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1.
  • Baptista, Antonio M. G., et al. (författare)
  • Causes of Vision Impairment in Portugal : A hospital based study
  • 2015
  • Ingår i: Investigative Ophthalmology and Visual Science. - 0146-0404 .- 1552-5783. ; 56:7
  • Tidskriftsartikel (refereegranskat)abstract
    • Purpose Causes of vision impairment (VI) are influenced by factors such as race or socio-economic circumstances. Because of this collecting national information is important for planning reduction of vision loss. The aim of this study was to determine causes of vision impairment in a population visiting ophthalmology departments in public hospitals in Portugal.Methods This study was designed according with the guidelines of the Vancouver Economic Burden of Vision Loss Group (IOVS, 2010, V51/4/1801). Recommendations are to collect hospital data during 1 year to determine causes of VI. We selected four public hospitals that are expected to have over 120-140K appointments per year. Files are analysed weekly to detect patients with vision impairment. Inclusion criteria are: visual acuity with the current refractive correction equal or less than 0.5 (20/40) in the better-seeing eye and/or a visual field of less than 20 degrees. Patients were selected by trained hospital staff (medics and orthoptists) and inserted in a database. Diagnoses were classified according the ICD9. Data collected included fundamental demographic information, main diagnosis, secondary diagnosis and comorbidities.Results We have now 2462 patients selected that correspond to 4 to 33 weeks of data collection. The number of weeks is variable because we did not start all hospitals simultaneously. From the current number of cases detected, 58% are female, 1.9% are under 20, 8.2% are between 20 and 50 and 89.9% are 50 years or older. The leading causes of vision impairment among these patients are diabetic retinopathy (DR), cataract (C), glaucoma (GC) and age-related macular degeneration (AMD). Using the North American definition of VI the proportions are 26.8% for DR, 25.5% for C, 10.4% for GC and 8.2% for AMD. The remaining causes of VI have percentages below 5% and in total they correspond to approximately 29% of the cases detected.Conclusions Our results show that the most common causes of vision impairment are eye diseases related with systemic conditions and aging of the population. Vision impairment was relatively low under the age of 20 and the causes were mostly inherited diseases. Numbers reported now will be more accurate at the end of the study but they already highlight the importance of targeting conditions such as diabetes.
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2.
  • Baptista, António M. G., et al. (författare)
  • The macular photostress test in diabetes, glaucoma, and cataract
  • 2013
  • Ingår i: 8th Iberoamerican Optics Meeting and 11th Latin American Meeting on Optics, Lasers, and Applications. - : SPIE - International Society for Optical Engineering.
  • Konferensbidrag (refereegranskat)abstract
    • Purpose. The photostress recovery time test (PSRT) has been widely reported as a helpful screening clinical tool. However, the poor standardization of its measurement technique remains to be a limitation among clinicians. The purpose of this study is to apply a recommended clinical technique to measure the PSRT in some of the most commons eye diseases to ascertain whether these diseases affect the PSRT values. Methods. One hundred and one controls and 105 patients, with diagnosed diabetes (without visible signs of diabetic retinopathy), primary open angle glaucoma (POAG) or cataracts underwent photostress testing. The test was performed with a direct ophthalmoscope for illuminating the macula for 30 seconds. Participants belonged to three age classes: A, B and C; and were divided into four groups: control, diabetic, POAG and cataract. The age range for A, B and C classes were respectively 43-54, 55-64 and 65-74 years. The groups were also further compared within each age class. In addition, the influence of age on PSRT was evaluated using the control group. Results. Results demonstrate that PSRT changes with age (p<0.02). In class A, diabetic group had a faster PSRT than control group, (mean ± standard deviation) 20.22±7.51 and 26.14±8.34 seconds. The difference between these groups was statistical significant (t-test, p=0.012). Cataract and POAG groups did not affect the PSRT significantly. Conclusions. The technique used for the Photostress showed that diabetics, younger than 54 years, may have faster PSRT and that, aging delays PSRT
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4.
  • Baskaran, Karthikeyan, Senior Lecturer, 1983-, et al. (författare)
  • Reading performance in Portuguese children from second to tenth grade with the MNREAD reading acuity test
  • 2023
  • Ingår i: Journal of Optometry. - : Elsevier. - 1888-4296. ; 16:4, s. 261-267
  • Tidskriftsartikel (refereegranskat)abstract
    • PurposeTo assess reading performance and report normative values for normal sighted Portuguese schoolchildren using the Portuguese version of the MNREAD reading acuity chart.MethodsChildren in the 2nd, 4th, 6th, 8th, and 10th grade in Portugal were recruited for this study. One hundred and sixty-seven children from 7 to 16 years of age participated. The Portuguese version of the printed MNREAD reading acuity chart was used to measure reading performance in these children. The non-linear mixed effects model with negative exponential decay function was used to compute maximum reading speed (MRS) and critical print size (CPS) automatically. Reading acuity (RA) and reading accessibility index (ACC) were computed manually.ResultsThe mean MRS in words-per-minute (wpm) for the 2nd grade was 55 wpm (SD = 11.2 wpm), 104 wpm (SD = 27.9) for the 4th grade, 149 wpm (SD = 22.5) for 6th grade, 172 wpm (SD = 24.6) for 8th grade and 180 wpm for the 10th grade (SD = 16.8). There was a significant difference in MRS between school grades (p < 0.001). Participants’ reading speed increased by 14.5 wpm (95% CL: 13.1–15.9) with each year of increase in age. We found a significant difference between RA and school grades, but not for CPS.ConclusionsThis study provides normative reading performance values for the Portuguese version of the MNREAD chart. The MRS increased with increasing age and school grade, while RA shows initial improvement from early school years and gradually stabilizes in the more mature children. Normative values for the MNREAD test can now be used to determine reading difficulties or slow reading speed in, for example, children with impaired vision.
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5.
  • Baskaran, Karthikeyan, Senior Lecturer, 1983-, et al. (författare)
  • Scoring reading parameters : An inter-rater reliability study using the MNREAD chart
  • 2019
  • Ingår i: PLOS ONE. - : Public Library of Science. - 1932-6203. ; 14:6, s. 1-14
  • Tidskriftsartikel (refereegranskat)abstract
    • Purpose First, to evaluate inter-rater reliability when human raters estimate the reading performance of visually impaired individuals using the MNREAD acuity chart. Second, to evaluate the agreement between computer-based scoring algorithms and compare them with human rating. Methods Reading performance was measured for 101 individuals with low vision, using the Portuguese version of the MNREAD test. Seven raters estimated the maximum reading speed (MRS) and critical print size (CPS) of each individual MNREAD curve. MRS and CPS were also calculated automatically for each curve using two different algorithms: the original standard deviation method (SDev) and a non-linear mixed effects (NLME) modeling. Intra-class correlation coefficients (ICC) were used to estimate absolute agreement between raters and/or algorithms. Results Absolute agreement between raters was ‘excellent’ for MRS (ICC = 0.97; 95%CI [0.96, 0.98]) and ‘moderate’ to ‘good’ for CPS (ICC = 0.77; 95%CI [0.69, 0.83]). For CPS, inter-rater reliability was poorer among less experienced raters (ICC = 0.70; 95%CI [0.57, 0.80]) when compared to experienced ones (ICC = 0.82; 95%CI [0.76, 0.88]). Absolute agreement between the two algorithms was ‘excellent’ for MRS (ICC = 0.96; 95%CI [0.91, 0.98]). For CPS, the best possible agreement was found for CPS defined as the print size sustaining 80% of MRS (ICC = 0.77; 95%CI [0.68, 0.84]). Absolute agreement between raters and automated methods was ‘excellent’ for MRS (ICC = 0.96; 95% CI [0.88, 0.98] for SDev; ICC = 0.97; 95% CI [0.95, 0.98] for NLME). For CPS, absolute agreement between raters and SDev ranged from ‘poor’ to ‘good’ (ICC = 0.66; 95% CI [0.3, 0.80]), while agreement between raters and NLME was ‘good’ (ICC = 0.83; 95% CI [0.76, 0.88]). Conclusion For MRS, inter-rater reliability is excellent, even considering the possibility of noisy and/or incomplete data collected in low-vision individuals. For CPS, inter-rater reliability is lower. This may be problematic, for instance in the context of multisite investigations or follow-up examinations. The NLME method showed better agreement with the raters than the SDev method for both reading parameters. Setting up consensual guidelines to deal with ambiguous curves may help improve reliability. While the exact definition of CPS should be chosen on a case-by-case basis depending on the clinician or researcher’s motivations, evidence suggests that estimating CPS as the smallest print size sustaining about 80% of MRS would increase inter-rater reliability.
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6.
  • Baskaran, Karthikeyan, Senior Lecturer, 1983-, et al. (författare)
  • Scoring reading parameters: an inter-rater reliability study using the MNREAD test
  • 2017
  • Konferensbidrag (refereegranskat)abstract
    • Aim: Estimating MNREAD parameters such as Critical Print Size (CPS) and Maximum Reading Speed (MRS) - using the time taken to read blocks of text - often requires subjective analysis of the reading profile. Depending on the rater, parameters may be over- or under-estimated, resulting in difficult or even impossible between-study comparisons. The aim of this project was to evaluate the inter-rater reliability of MNREAD parameters in subjects with visual impairment. Methods: Reading times for the Portuguese version of the MNREAD chart from 32 subjects, reading binocularly were analyzed. Reading speed was computed by a single experimenter (AFM) using reading time and number of errors. Based on reading speeds, three experimented raters (AFM, AC and KB) computed MRS and CPS using the following method. CPS was defined as the print size at which subsequent smaller print sizes were read at 1.96 x standard deviation slower than the mean of the preceding print sizes; MRS was estimated as the mean reading speed for sentences in print larger than the CPS. Inter-rater reliability was assessed using intra-class correlation (ICC) coefficient for both MRS and CPS for all three raters. Results: Near acuity range was 0.14-1.9 logMAR. The average measure ICC for CPS was 0.896 with a 95% CI from 0.814 to 0.946 (p< 0.001). The average measure ICC for MRS was 0.984 with a 95% CI from 0.970 to 0.992 (p< 0.001). Conclusion: A high degree of reliability was found between the three raters for both CPS and MRS. Even though some small variability exists this may be due to raters’ high-level experience with MNREAD data. Future directions will involve: 1) including more raters with various level of experience in MNREAD rating; 2) investigating the degree of inter-rater reliability for raters using different estimation methods.
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7.
  • Baskaran, Karthikeyan, Senior Lecturer, 1983-, et al. (författare)
  • Swedish version of the Massof activity inventory to measure vision-related activity difficulties among patients with nAMD
  • 2024
  • Ingår i: Acta Ophthalmol, vol 102, issue S279: Special Issue:Abstracts from the 2023 European Association for Vision and Eye Research Festival, 26‐28 October 2023, Valencia. - : John Wiley & Sons.
  • Konferensbidrag (refereegranskat)abstract
    • Aims/Purpose: The aim of this study was to assess vision-related activity difficulties among patients with neovascular AMD using a Swedish version of the mass of activity inventory (MAI). Methods: Participants were patients diagnosed with neovascular AMD receiving treatment for the disease in a hospital in southeast Sweden. Participants completed the Swedish version of the MAI questionnaire. MAI can be used to measure the overall visual ability and visual ability in 4 functional domains: reading, mobility, visual motor function and visual information processing. Best corrected distance and near visual acuity (VA) were also measured. Results: Among the 196 participants (mean age=78.5 years, SD=7.67, 66% female) the median VA in the better seeing eye was 0.18 logMAR (IQR=?0.34), and in the worse eye was 0.54 logMAR (IQR=0.98). The median visual ability for all participants was 1.92 logits (IQR=2.69). There was a significant negative correlation between distance VA in the better eye and visual ability (rho=0.4025, p<0.01). Using ROC curves, we tested the capacity of the MAI to detect cases of any vision impairment (VA worse than 0.3 logMAR in the better seeing eye), the area under the curve (AUC) was 0.717 (95% CI=0.643 - 0.791 p<0.001). When we tested for detection of moderate vision impairment (VA worse than 0.5 logMAR in the better seeing eye) the AUC was 0.738 (95% CI=0.648 - 0.829 p?<0.001). Conclusions: The results indicate that the Swedish version of the MAI produce measures of visual ability that are consistent with clinical measures among patients with nAMD. The Swedish version of the MAI can be used as outcome measure in interventions for people with nAMD.References1. Macedo, A.F. et al. Predictors of problems reported on the EQ-5D-3L dimensions among people with impaired vision in northern Portugal. Health Qual Life Outcomes 2022; 20: 132.
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8.
  • Carneiro de Freitas, Rui, et al. (författare)
  • Prevalence of Visual Impairment in Portugal : study design and initial results
  • 2015
  • Ingår i: Investigative Ophthalmology and Visual Science. - 0146-0404 .- 1552-5783. ; 56:7
  • Tidskriftsartikel (refereegranskat)abstract
    • Purpose Information about the prevalence of visual impairment is fundamental to define policies that deal with vision loss. The aim of this study is to determine the prevalence of visual impairment (VI) in the population looking for eye care in public hospitals in Portugal.Methods We designed an observation, cross-sectional prospective study (Prevalence and Costs of Visual Impairment in Portugal: PC-VIP study) to investigate the prevalence of VI in patients attending outpatient appointments in four public hospitals in Portugal. Hospital selected provide from general eye care (3-6 ophthalmologists) to high-specialized eye care (40+ ophthalmologists) that in total have between 120-140K hospital appointments per year. Files of patients are analysed weekly to detect patients with VI. Inclusion criteria were: visual acuity equal or worse than 0.5 (USA definition 20/40) in the better eye and/or a visual field of less than 20deg. Cases are selected by trained hospital staff and inserted in a database. Data collected included demographic information, acuity from both eyes, qualitative information about visual field (good, reduced, requires investigation), main diagnosis, secondary diagnosis and comorbidities. Diagnoses were classified according with ICD9.Results We have now detected 2462 cases of VI that correspond to 4 to 33 weeks of data collection. The number of weeks is variable because collection did not start simultaneously in all sites. From the number of cases detected, 58% were female, 1.9% were under 20y, 8.2% were between 20y and 50y and 89.9% were ≥50y. The mean prevalence of visual impairment was 13.6% (SD=5.6) using the USA definition and it was 7.0%(SD=4.1) using the WHO definition (acuity equal or worse than 0.3 or ~20/63). With a methodology that controls for demographics the lowest and highest estimates were calculated. Considering the USA definition, the prevalence in the general population would be in the range 0.4 -0.4% (age<40y) and 0.8-2.4% (age>=40y). Considering WHO definition, it would be 0.2-0.5% (age<40y) and 0.4-1.0% (age>=40y).Conclusions A hospital-based study can provide effective estimates of the prevalence of visual impairment in a population. Estimates for the country are in agreement with the expected results that can be deducted from neighbour countries and self-reported visual impairment in census 2001.
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9.
  • Cima, Joana, et al. (författare)
  • EQ-5D and Activity Inventory : Measures of Visual Health Outcome
  • 2015
  • Ingår i: European Journal of Public Health. - : Oxford University Press (OUP). - 1101-1262 .- 1464-360X. ; 25:Suppl 3
  • Tidskriftsartikel (refereegranskat)abstract
    • The aim of the study is to test if EQ-5D, a more generic instrument, and Activity Inventory, a more specific instrument to the visual condition, produce consistent results when considering the different levels of visual impairment. By assessing how these instruments reflect visual status in a sample of patients with visual impairment, we will help to understand how they can work in cultural context and population in which they were never tested before.Method is based on Multivariate Analysis of Variance, in which the levels of visual impairment (slightly, moderate, severe/blindness) are defined through the visual acuity values, and the utility values derived from EQ-5D and the Activity Inventory.Participants were recruited in 3 public hospitals as a part of an ongoing study of prevalence and costs of visual impairment in Portugal. Patients attending outpatient appointments in these hospitals with acuity in the better eye of 0,30logMAR or worse and/or visual field in the better eye <20 degrees were invited to take part in face-to-face interviews. Additional visual measures, as acuity was collected using standardize methods. Visual acuity was assessed using an internally illuminated ETDRS chart at 4 m with room lights extinguished.The results show that both instruments have a good explanatory power. However when considering different clinical conditions, the AI presents better results. The EQ-5D due its low sensitivity/adaptability does not capture differences in health status in patients with slightly and moderate visual impairment.Since EQ-5D is the instrument most used in the evaluation of public health programs performance, the results suggest that its use should be more cautious in a situation of different difficulty levels. The results indicate that in these cases the EQ-5D should be used with a complementary instrument more specific to the clinical condition.Key messagesThe results suggest that with different difficulty levels the EQ-5D should be used with a complementary instrument more specific to the clinical condition to be produced more reliable resultsThis study is supported by the Portuguese Foundation for Science and Technology (FCT) -POCTI & FSE GRANT: PTDC/DPT-EPI/0412/2012
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10.
  • Crossland, Michael D., et al. (författare)
  • Smartphone, tablet computer and e-reader use by people with vision impairment
  • 2014
  • Ingår i: Ophthalmic & physiological optics. - : Wiley. - 0275-5408 .- 1475-1313. ; 34:5, s. 552-557
  • Tidskriftsartikel (refereegranskat)abstract
    • PURPOSE:Consumer electronic devices such as smartphones, tablet computers, and e-book readers have become far more widely used in recent years. Many of these devices contain accessibility features such as large print and speech. Anecdotal experience suggests people with vision impairment frequently make use of these systems. Here we survey people with self-identified vision impairment to determine their use of this equipment.METHOD:An internet-based survey was advertised to people with vision impairment by word of mouth, social media, and online. Respondents were asked demographic information, what devices they owned, what they used these devices for, and what accessibility features they used.RESULTS:One hundred and thirty-two complete responses were received. Twenty-six percent of the sample reported that they had no vision and the remainder reported they had low vision. One hundred and seven people (81%) reported using a smartphone. Those with no vision were as likely to use a smartphone or tablet as those with low vision. Speech was found useful by 59% of smartphone users. Fifty-one percent of smartphone owners used the camera and screen as a magnifier. Forty-eight percent of the sample used a tablet computer, and 17% used an e-book reader. The most frequently cited reason for not using these devices included cost and lack of interest.CONCLUSIONS:Smartphones, tablet computers, and e-book readers can be used by people with vision impairment. Speech is used by people with low vision as well as those with no vision. Many of our (self-selected) group used their smartphone camera and screen as a magnifier, and others used the camera flash as a spotlight.
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11.
  • Crossland, Michael, et al. (författare)
  • Electronic books as low vision aids
  • 2010
  • Ingår i: British Journal of Ophthalmology. - : BMJ. - 0007-1161 .- 1468-2079. ; 94:8, s. 1109-
  • Tidskriftsartikel (refereegranskat)abstract
    • Recently, several electronic book readers have become commercially available. These consist of a low glare electronic paper screen and internal memory, which can typically hold the full text of between 150 and 2000 full-length novels. Electronic paper has a wide viewing angle of almost 1808 but a slow refresh speed of about 250 ms. Amazon’s Kindle device has 300 000 books available in electronic format, and 11 000 are available through Waterstones in the UK for the Sony Reader. Table 1 shows the parameters of these and other popular electronic books. Here, we explore the utility of these two electronic books for use by the visually impaired.
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12.
  • Crossland, Michael, et al. (författare)
  • Use of tablet computers and e-readers by people with visual impairment
  • 2014
  • Ingår i: Clinical and experimental optometry. - : Informa UK Limited. - 0816-4622 .- 1444-0938. ; 97, s. e19-e19
  • Tidskriftsartikel (refereegranskat)abstract
    • Background: We have observed many people with visual impairment using tablet computers and electronic books and have previously shown that these devices can be used by people with relatively low visual acuity and contrast sensitivity.Method: An online survey was advertised to people with visual impairment using personal contacts, social media and online discussion groups. Participants were asked to specify whether they used tablet computers and/or electronic books and if so, which device they used, what they used the device for and which accessibility functions they used.Results: Forty-four of 75 (59 per cent) respondents used a tablet computer. Of these, 30 (65 per cent) used an Apple iPad. All tablet users accessed the internet on their device and more than half read electronic books, took photographs and used apps. The ability to enlarge print was seen as the most useful accessibility option, cited by 76 per cent. Forty-nine per cent used contrast adjustment and 58 per cent used speech. Only 16 of the 75 respondents (22 per cent) used an electronic reader. Enlarged print was the most popular accessibility option on ereaders.Conclusions: Tablet computers are widely used by people with visual impairment. Large print is the most commonly used accessibility option, although speech and contrast reversal are also frequently used.
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13.
  • Daelman, Bo, et al. (författare)
  • Frailty and cognitive function in middle-aged and older adults with congenital heart disease
  • 2024
  • Ingår i: Journal of the American College of Cardiology. - : Elsevier. - 0735-1097 .- 1558-3597. ; 83:12, s. 1149-1159
  • Tidskriftsartikel (refereegranskat)abstract
    • Background: Life expectancy of patients with congenital heart disease (CHD) has increased rapidly, resulting in a growing and aging population. Recent studies have shown that older people with CHD have higher morbidity, health care use, and mortality. To maintain longevity and quality of life, understanding their evolving medical and psychosocial challenges is essential.Objectives: The authors describe the frailty and cognitive profile of middle-aged and older adults with CHD to identify predictor variables and to explore the relationship with hospital admissions and outpatient visits.Methods: Using a cross-sectional, multicentric design, we included 814 patients aged ≥40 years from 11 countries. Frailty phenotype was determined using the Fried method. Cognitive function was assessed by the Montreal Cognitive Assessment.Results: In this sample, 52.3% of patients were assessed as robust, 41.9% as prefrail, and 5.8% as frail; 38.8% had cognitive dysfunction. Multinomial regression showed that frailty was associated with older age, female sex, higher physiologic class, and comorbidities. Counterintuitively, patients with mild heart defects were more likely than those with complex lesions to be prefrail. Patients from middle-income countries displayed more prefrailty than those from higher-income countries. Logistic regression demonstrated that cognitive dysfunction was related to older age, comorbidities, and lower country-level income.Conclusions: Approximately one-half of included patients were (pre-)frail, and more than one-third experienced cognitive impairment. Frailty and cognitive dysfunction were identified in patients with mild CHD, indicating that these concerns extend beyond severe CHD. Assessing frailty and cognition routinely could offer valuable insights into this aging population.
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14.
  • Demir, Pelsin, 1994-, et al. (författare)
  • All retinas are not created equal : Fovea‐to‐macula thickness ratio and foveal microvasculature in healthy young children
  • 2022
  • Ingår i: Ophthalmic & physiological optics. - : John Wiley & Sons. - 0275-5408 .- 1475-1313. ; 42:3, s. 644-652
  • Tidskriftsartikel (refereegranskat)abstract
    • Purpose: Markers for the relationships between structural and microvasculature measures given by optical coherence tomography angiography are necessary to increase the diagnostic and prognostic value of this technique. The aim of this study was to investigate relationships between structural and microvasculature measures around the fovea in healthy eyes of healthy children.Methods: Observational cross-sectional study involving children aged 8–17 years, born at full-term, with no eye disease. The better of two 3 × 3 mm macular scans obtained with a Cirrus 5000HD-OCT was analysed. Images were corrected for lateral magnification errors. Vessel density and perfusion were measured with ImageJ/Fiji software for the superficial capillary plexus. Structural measures including foveal and macular thicknesses were performed manually.Results: The sample included 86 participants, 51 (59%) females. Mean age was 12.4 years (SD = 2.5); mean best-corrected acuity was −0.10 logMAR (SD = 0.09); mean refractive error was +0.59 D (SD = 1.3) and mean axial length was 23.1 mm (SD = 0.86). Mean area of the foveal avascular zone (AFAZ) was 0.20 mm2 (SD = 0.88); median fovea-to-macula thickness ratio (FMTR) was 0.63 (IQR = 0.08); mean central vessel density was 12.42 mm−1 (SD = 2.78) and mean central perfusion was 38.66% (SD = 3.83). AFAZ was correlated with central vessel density (p < 0.001), perfusion (p < 0.001), foveal thickness (p < 0.001) and FMTR (p < 0.001). Central vessel density was correlated with foveal thickness (p < 0.001) and FMTR, (p = 0.01). Central perfusion was correlated with foveal thickness (p < 0.001) and FMTR, (p = 0.003).Conclusion: In this study, foveal thickness, FMTR and foveal microvasculature measurements were correlated. Clinicians need to be aware that shallow foveal pits and persistent foveal microvasculature are likely to occur in optical coherence tomography angiography images. In healthy eyes from healthy children, an atypical high FMTR and a small AFAZ may be associated with incomplete foveal development. The mechanism and functional implications of this remain unknown.
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15.
  • Demir, Pelsin, 1994-, et al. (författare)
  • Comparison of an open view autorefractor with an open view aberrometer in determining peripheral refraction in children
  • 2023
  • Ingår i: Journal of Optometry. - : Elsevier. - 1888-4296. ; 16:1, s. 20-29
  • Tidskriftsartikel (refereegranskat)abstract
    • PurposeThe aim of this study was to compare central and peripheral refraction using an open view Shin-Nippon NVision-K 5001 autorefractor and an open view COAS-HD VR aberrometer in young children.MethodsCycloplegic central and peripheral autorefraction was measured in the right eye of 123 children aged 8 to 16 years. Three measurements each were obtained with both Shin-Nippon NVision-K 5001 autorefractor and COAS-HD VR aberrometer along the horizontal visual field up to 30° (nasal and temporal) in 10° steps. The refraction from the autorefractor was compared with aberrometer refraction for pupil analysis diameters of 2.5-mm and 5.0-mm.ResultsThe Shin-Nippon was 0.30 D more hyperopic than COAS-HD VR at 2.5-mm pupil and 0.50 D more hyperopic than COAS-HD VR at 5-mm pupil for central refraction. For both pupil sizes, the 95% limits of agreement were approximately 0.50 D for central refraction, and limits were wider in the nasal visual field compared to the temporal visual field. The mean difference for both J0 and J45 were within 0.15 D and the 95% limits of agreement within 0.90 D across the horizontal visual field.ConclusionDefocus components were similar between the Shin-Nippon autorefractor and the COAS-HD VR aberrometer with a 2.5-mm pupil for most visual field angles. However, there was a significant difference in defocus component between the Shin-Nippon autorefractor and the COAS-HD VR aberrometer with a 5.0-mm pupil, wherein the autorefractor measured more hyperopia. The astigmatic components J0 and J45 were similar between instruments for both central and peripheral refraction.
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16.
  • Demir, Pelsin, 1994-, et al. (författare)
  • Incidence of myopia in Swedish schoolchildren : A longitudinal study.
  • 2024
  • Ingår i: Ophthalmic & physiological optics. - : John Wiley & Sons. - 0275-5408 .- 1475-1313. ; 44:6, s. 1301-1308
  • Tidskriftsartikel (refereegranskat)abstract
    • PURPOSE: The prevalence of myopia in Scandinavia tends to be lower than in other parts of the world. This study aimed to investigate the incidence of myopia and its predictors in Swedish children to characterise this trend.METHODS: A 2-year longitudinal study was conducted following a cohort of schoolchildren aged 8-16 years. Myopia was defined as a spherical equivalent refraction (SER) ≤ -0.50 D. The study enrolled 128 participants, 70 (55%) females with a mean age of 12.0 years (SD = 2.4).RESULTS: The cumulative incidence of myopia during the follow-up period was 5.5%, and the incidence rate of myopia was 3.2 cases per 100 person-years. Participants with myopia at baseline exhibited a faster increase in refractive error during the follow-up period. Likewise, participants with two myopic parents exhibited a more marked change towards myopia, regardless of their initial refractive error.CONCLUSION: In the current study, similar to prevalence, the incidence of myopia was low when compared with other parts of the world. These results lead us to formulate a new hypothesis that the normal emmetropisation process may be protected by low educational pressure practised in Sweden during early childhood. Further research is necessary to test this new hypothesis.
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17.
  • Demir, Pelsin, 1994- (författare)
  • Prevalence of refractive errors and incidence of myopia in Swedish schoolchildren
  • 2022
  • Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
    • PurposeThe aim of this thesis was to investigate the prevalence, incidence, and risk factors for myopia development in a cohort of Swedish schoolchildren. The specific goals were: - to recruit a cohort of children aged 8 to 16 years and to follow the cohort over a period of 24 months with regular study visits; - to investigate the predictive value of relative peripheral error and other optical parameters for the prevalence and incidence of myopia; - to determine and investigate the predictive value of genetic and environmental factors, and structural characteristics of the eye to the incidence of myopia.MethodsThis was a longitudinal study with a follow-up period of 2-years conducted at Linnaeus University in Kalmar. All participants underwent eye examinations and completed questionnaires at regular intervals during the follow-up period. Data analysis was performed assuming hypotheses such as: - myopia development is associated with genetic factors and environmental factors (Papers I and IV); - changes in refractive error over time are explained by multiple genetic and environmental factors (Paper IV) - instruments with different measurement principles can lead to different refraction results (Paper II); - there is a relationship between refractive error and the characteristics of the choroid (Exploratory study, not published) and the characteristics of the microvasculature of the retina (Paper III).ResultsA total of 128 children (70 females and 58 males) participated in this study with mean age of 12.0 years (SD=2.4). Paper I: based on cycloplegic SER of the right eye, the distribution of refractive errors was: hyperopia 48.0% (CI95=38.8-56.7), emmetropia 42.0% (CI95=33.5-51.2) and myopia 10.0%. (CI95=4.4-14.9). Participants with two myopic parents had higher myopia and increased axial length than those with one or no myopic parents. Paper II: The Shin-Nippon was 0.30 D more hyperopic than COAS-HD VR at 2.5-mm pupil and 0.50 D more hyperopic than COAS-HD VR at 5-mm pupil for central refraction. Paper III: The sample included 86 out of the 128 participants, 51 (59%) females. The area of the foveal avascular zone (AFAZ) was correlated with central vessel density, perfusion, foveal thickness and with fovea-to-macula thickness ratio. Paper IV: The cumulative incidence of myopia during the two-years was 5.5%, incidence rate of myopia was 3.2 cases per 100 person-years. Cox regression revealed that the probability of myopic shift reduced with “age” and increased with “axial length/corneal-curvature ratio”. Myopic children at the baseline and children with two myopic parents showed a significant faster-paced SER change over time.ConclusionThe prevalence and incidence of myopia in Sweden was lower than expected when compared with countries in East Asia. Genetic factors such as parental myopia remains a critical factor to consider when predicting myopia onset and progression. Children born full-term and visual acuity within the normal range can have very different retinal microvasculature at the centre of the macula that may influence refractive error development. Future studies are necessary to find out possible relationships between vasculature, structural changes and refractive error development. In addition, more studies involving children from different ethnicities and incorporating longer follow-up period are necessary to increase our understanding of the incidence of myopia in Swedish schoolchildren.
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18.
  • Demir, Pelsin, 1994-, et al. (författare)
  • Refractive error, axial length, environmental and hereditary factors associated with myopia in Swedish children
  • 2021
  • Ingår i: Clinical and experimental optometry. - : Taylor & Francis Group. - 0816-4622 .- 1444-0938. ; 104:5, s. 595-601
  • Tidskriftsartikel (refereegranskat)abstract
    • Clinical relevance: Investigation of refractive errors amongst Swedish schoolchildren will help identify risk factors associated with myopia development.Background: Genetic and hereditary aspects have been linked with the development of myopia. Nevertheless, in the case of ‘school myopia’ some authors suggest that environmental factors may affect gene expression, causing school myopia to soar. Additional understanding about which environmental factors play a relevant role can be gained by studying refractive errors in countries like Sweden, where prevalence of myopia is expected to be low.Methods: Swedish schoolchildren aged 8-16 years were invited to participate. Participants underwent an eye examination, including cycloplegic refraction and axial length (AL) measurements. Predictors such as time spent in near work, outdoor activities and parental myopia were obtained using a questionnaire. Myopia was defined as spherical equivalent refraction (SER) ≤ −0.50D and hyperopia as SER ≥ +0.75D.Results: A total of 128 children (70 females and 58 males) participated in this study with mean age of 12.0 years (SD = 2.4). Based on cycloplegic SER of the right eye, the distribution of refractive errors was: hyperopia 48.0% (CI95 = 38.8-56.7), emmetropia 42.0% (CI95 = 33.5-51.2) and myopia 10.0%. (CI95 = 4.4-14.9). The mean AL was 23.1 mm (SD = 0.86), there was a correlation between SER and AL, r = −0.65 (p < 0.001). Participants with two myopic parents had higher myopia and increased axial length than those with one or no myopic parents. The mean time spent in near work, outside of school, was 5.3 hours-per-day (SD = 3.1), and mean outdoor time reported was 2.6 hours-per-day (SD = 2.2) for all the participants. The time spent in near work and outdoor time were different for different refractive error categories.Conclusion: The prevalence of myopia amongst Swedish schoolchildren is low. Hereditary and environmental factors are associated with refractive error categories. Further studies with this sample are warranted to investigate how refractive errors and environmental factors interact over time.
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19.
  • Ferreira, Marisa Borges, et al. (författare)
  • Relationships between neuropsychological and antisaccade measures in multiple sclerosis patients
  • 2018
  • Ingår i: PeerJ. - : PeerJ, Inc. - 2167-8359. ; 6, s. 1-18
  • Tidskriftsartikel (refereegranskat)abstract
    • BackgroundThe Stroop test is frequently used to assess deficits in inhibitory control in people with multiple sclerosis (MS). This test has limitations and antisaccade eye movements, that also measure inhibitory control, may be an alternative to Stroop.ObjectivesThe aim of this study was twofold: (i) to investigate if the performance in the antisaccade task is altered in patients with MS and (ii) to investigate the correlation between performances in neuropsychological tests, the Stroop test and the antisaccade task.MethodsWe measured antisaccades (AS) parameters with an infrared eye tracker (SMIRED 250 Hz) using a standard AS paradigm. A total of 38 subjects diagnosed with MS and 38 age and gender matched controls participated in this study. Neuropsychological measures were obtained from the MS group.ResultsPatients with MS have higher error rates and prolonged latency than controls in the antisaccade task. There was a consistent association between the Stroop performance and AS latency. Stroop performance but not AS latency was associated with other neuropsychological measures in which the MS group showed deficits.ConclusionsOur findings suggest that AS may be a selective and independent measure to investigate inhibitory control in patients with MS. More studies are necessary to confirm our results and to describe brain correlates associated with impaired performance in the antisaccade task in people diagnosed with MS.
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20.
  • Freitas, Cristina, et al. (författare)
  • Functional impairment with minimal macular damage in femtosecond laser plasma injury : case report : [ Comprometimento funcional com dano macular mínimo em lesão com plasma de laser de femtosegundo: relato de caso ]
  • 2013
  • Ingår i: Arquivos Brasileiros de Oftalmologia. - 0004-2749 .- 1678-2925. ; 76:5, s. 317-319
  • Tidskriftsartikel (refereegranskat)abstract
    • A 26 years old female patient was examined twenty-four hours after observing laser-induced plasma formation in a process of nanoparticle production complaining of bilateral central scotoma. The ophthalmologic evaluation included dilated fundus observation, fluorescein angiography, and optical coherence tomography (OCT). In the first assessment, visual acuity was 20/20 in the right eye and 20/25 in the left eye. Ophthalmologic evaluation revealed colour changes in the macular region of both eyes. Optical coherence tomography showed a central interruption of the photoreceptor layer in both eyes and fluorescein angiography was normal. In subsequent appointments acuity was always 20/20 in both eyes. Abnormal optical coherence tomography findings disappeared in less than 5 months, but subjective complaints of scotoma in the left eye remained. Extra care must be taken in this type of experiment by, for example, reducing the time that the retina is directly exposed to the plasma radiation. 
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21.
  • Goncalves Fernandes Ferreira, Flavio Pedro, et al. (författare)
  • Artificial eye for calibration of an eye-tracker, eye tracking calibration system and method thereof
  • 2021
  • Patent (populärvet., debatt m.m.)abstract
    • Abstract(EN) An artificial eye for eye tracking calibration of an eye-tracker, comprising: an eye model comprising a foveal region; an optical position sensor arranged at the foveal region for transducing the position of a foveal light spot into a sensor position signal; a two-axis rotational pivoting support upon which the eye model is mounted; a two-axis actuator for rotating the eye model in said pivoting support; a feed-back electronic circuit, connected between the sensor and actuator, arranged to cause rotation of the eye model by said actuator such that the sensor position signal matches a reference position signal. The reference position signal may be adjustable to cause an off-set between the pupillary-axis of the eye model and a visual-axis defined by the reference position signal, in particular the reference position signal being adjustable by configuration of the feed-back electronic circuit.(FR) L'invention concerne un oeil artificiel pour l'étalonnage de suivi de l'oeil d'un oculomètre, comprenant : un modèle d'oeil comprenant une région fovéale ; un capteur de position optique disposé au niveau de la région fovéale pour convertir la position d'un point lumineux fovéal en un signal de position de capteur ; un support pivotant rotatif à deux axes sur lequel est monté le modèle oculaire ; un actionneur à deux axes pour faire tourner le modèle d'oeil dans ledit support pivotant ; un circuit électronique de rétroaction, connecté entre le capteur et l'actionneur, agencé pour provoquer la rotation du modèle d'oeil par ledit actionneur de telle sorte que le signal de position de capteur corresponde à un signal de position de référence. Le signal de position de référence peut être réglé pour provoquer un décalage entre l'axe pupillaire du modèle d'oeil et un axe visuel défini par le signal de position de référence, en particulier le signal de position de référence étant réglable par la configuration du circuit électronique de rétroaction.
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22.
  • Hernandez-Moreno, Laura, et al. (författare)
  • Absent Foveal Pit, Also Known as Fovea Plana, in a Child without Associated Ocular or Systemic Findings
  • 2018
  • Ingår i: Case Reports in Ophthalmological Medicine. - : Hindawi Publishing Corporation. - 2090-6722 .- 2090-6730. ; , s. 1-5
  • Tidskriftsartikel (refereegranskat)abstract
    • The purpose of this report is to describe a case of bilateral foveal hypoplasia in the absence of other ophthalmological or systemic manifestations. We characterize the case of a 9-year-old Caucasian male who underwent full ophthalmologic examination, including functional measures of vision and structural measurements of the eye. Best corrected visual acuity was 0.50 logMAR in the right eye and 0.40 logMAR in the left eye. Ophthalmoscopy revealed a lack of foveal reflex that was further investigated. Optical coherence tomography (OCT) confirmed the absence of foveal depression (pit). OCT images demonstrated the abnormal structure of retina in a region in which we expected a fovea; these findings were decisive to determine the cause of reduced acuity in the child.
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23.
  • Hernández-Moreno, Laura, et al. (författare)
  • Cost‐effectiveness of basic vision rehabilitation (The basic VRS‐effect study): study protocol for a randomised controlled trial
  • 2020
  • Ingår i: Ophthalmic & physiological optics. - : John Wiley & Sons. - 0275-5408 .- 1475-1313. ; 40:3, s. 350-364
  • Tidskriftsartikel (refereegranskat)abstract
    • Abstract Purpose To investigate the cost-effectiveness of a basic vision rehabilitation service (basic-VRS) in Portugal. We designed a parallel group, randomised controlled trial whose aim is to compare the effects and costs of ?usual low vision care? with a ?basic-VRS intervention? on self-reported visual ability and other psychosocial and health-related quality-of-life outcomes. Methods The trial will recruit participants that meet the following inclusion criteria: (1) visual acuity between 0.4?1.0 logMAR in the better-seeing eye, (2) cause of vision loss is diabetic retinopathy or age-related macular degeneration, (3) 18 years or older and iv) live in the community (not in nursing homes or other type of institution). Participants will be randomised to one of the study arms consisting of immediate intervention and delayed intervention. The delayed intervention group will receive ?usual care? or no intervention in the first 12 weeks. Visual acuity, contrast sensitivity and retinal structure will be assessed during the study. Results The primary outcome measure is visual ability, which will be evaluated with the Massof Activity Inventory, we expect that the intervention will raise the overall person measure or visual ability. Reading, health-related quality-of-life, anxiety and depression and social support will be also assessed. The analysis will be undertaken on an intention-to-treat basis. A cost-effectiveness analysis will be performed to provide information about the cost per unit of utility. To evaluate the cost-effectiveness of the intervention we will adopt the perspective of the healthcare system. Conclusion This study will provide additional evidence about the effects of basic-VRS on self-reported visual ability. Findings from this study should also contribute to better planning of low vision provision and, consequently, may contribute to reduce barriers to basic-VRS.
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24.
  • Hernández-Moreno, Laura, et al. (författare)
  • Is perceived social support more important than visual acuity for clinical depression and anxiety in patients with age-related macular degeneration and diabetic retinopathy? : Är uppfattat socialt stöd viktigare än synskärpa för klinisk depression och ångest hos patienter med åldersrelaterad makulär degeneration och diabetesretinopati?
  • 2021
  • Ingår i: Clinical Rehabilitation. - : Sage Publications. - 0269-2155 .- 1477-0873. ; 35:9, s. 1341-1347
  • Tidskriftsartikel (refereegranskat)abstract
    • Objective:To investigate whether visual acuity has the same importance as a factor of depression and anxiety comparing with other psychological variables, particularly perceived social support, in patients diagnosed with age-related eye diseases, with and without low vision.Design:Observational cross-sectional study.Setting:Patients attending outpatient appointments at the department of ophthalmology of a general hospital in Portugal.Subjects:Patients with age-related macular degeneration and patients with diabetic retinopathy attending routine hospital appointments were recruited for this study.Measures:Anxiety and depression were measured using the hospital anxiety and depression scale and perceived social support using the multidimensional scale of perceived social support. Visual acuity was measured with ETDRS charts.Results:Of the 71 patients, 53 (75%) were diagnosed with diabetic retinopathy, 37 (52%) were female and age (mean±SD) was 69±12 years. Acuity in the better seeing eye was 0.41±?0.33logMAR. The mean anxiety score was 4.38±3.82 and depression 4.41±3.39. Clinically significant levels of anxiety were found in 21% (n=15) of the participants and depression in 18%(n=13). The total social support score was 5.29±0.61. Significant multivariate regression models were found for anxiety (R2=0.21, P=0.016) and for depression (R2=0.32, P<0.0001). Social support was independently associated with levels of anxiety and with levels of depression. Gender was independently associated with levels of anxiety.Conclusion:This study suggests that patients? perceived social support might be more important than visual acuity as a factor of clinical depression and anxiety in a sample of age-related eye disease patients.
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25.
  • Hernández-Moreno, Laura, et al. (författare)
  • The Basic VRS-Effect Study : Clinical Trial Outcomes and Cost-Effectiveness of Low Vision Rehabilitation in Portugal
  • 2023
  • Ingår i: Ophthalmology and Therapy. - : Springer. - 2193-8245 .- 2193-6528. ; 12, s. 307-323
  • Tidskriftsartikel (refereegranskat)abstract
    • IntroductionThe aim of this study was twofold: (1) to investigate the clinical impact of vision rehabilitation in patients with vision impairment and (2) to investigate the cost-effectiveness of a basic vision rehabilitation service in Portugal.MethodsThe trial recruited patients diagnosed with age-related macular degeneration or diabetic retinopathy (DR) and visual acuity in the range 0.4–1.0logMAR in the better-seeing eye. Participants were randomised to one of the study arms consisting of immediate intervention and delayed intervention. The intervention included: new refractive correction, optical reading aids, in-office training and advice about modifications at home. Visual ability, health-related quality of life and costs were measured. Economic analysis was performed to evaluate whether the intervention was cost-effective. The trial compared the outcomes 12 weeks after the start in both arms.ResultsOf the 46 participants, 34 (74%) were diagnosed with DR, 25 (54%) were female, and mean age was 70.08 years (SD = 8.74). In the immediate intervention arm visual ability increased a mean of 0.523 logits (SE = 0.11) (p < 0.001). Changes in the delayed intervention arm were not statistically significant (p = 0.95). Acuity in the better-seeing eye, near acuity and critical print size also improved during the study. The mean cost of the intervention was €118.79 (SD = 24.37). The incremental cost-effectiveness ratio using the EQ-5D-5L was 30,421€/QALY and 1186€/QALY when using near acuity.ConclusionThe current study gives evidence of positive clinical impact of a basic vision rehabilitation intervention and shows that a basic vision rehabilitation service is cost-effective. These findings are important to clinical and rehabilitation practices and for planning vision rehabilitation services.Trial RegistrationRetrospectively registered, 21/01/2019. ISRCTN10894889, https://www.isrctn.com/ISRCTN10894889
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26.
  • Hernández-Moreno, Laura, et al. (författare)
  • The Portuguese version of the activity inventory
  • 2015
  • Ingår i: Investigative Ophthalmology and Visual Science. - 0146-0404 .- 1552-5783. ; 56:7
  • Tidskriftsartikel (refereegranskat)abstract
    • Purpose: To characterize interventions needed by the population with visual impairment or to assess interventions in vision rehabilitation validated and standardized instruments used in different cultural contexts are necessary. The aim of this work was to characterize the functional status of a sample of people with visual impairment with the Portuguese version of the activity inventory (AI)Methods: A group of participants in the study Prevalence and Costs of Visual Impairment in Portugal (PC-VIP) was recruit to face-to-face interviews and the activity inventory was administered. The AI examines 50 goals split between three objectives: social functioning, recreation and daily living. Goals rated ‘not important’ were skipped, but for all other goals the participant was asked to rate its difficulty on a five point scale ranging from ‘not difficult’ to ‘impossible without help’. The difficulty responses were Rasch analysed (Winsteps v3.81.0) to produce a continuous measure of visual ability (AI score). Additional information about distance and near visual acuity (ETDRS scale), contrast sensitivity (MARS test) and critical print size (MNREAD test) was collected.Results: A total of 94 persons participated in this study. Some participants were not able to read or recognize letters due to their poor vision or poor literacy and were excluded from further analysis. Data reported here are from 62 participants, median age 63y (range=12-85) and the most common cause of visual impairment were retinal diseases. Mean presenting acuity in the better eye was 0.93logMAR (SD=0.5). The mean difficulty (item measure) in the AI was -0.33 logits (SD=0.96). The most difficult items were "sew or do needlework", "read the newspaper", "drive" and the easiest items were "provide care for a pet", "eat your meals", "use the restroom in a public place". The mean ability score (person measures) was 1.11 logits (SD=2.04). The ability measures in the AI were correlated with distance visual acuity (r=-0.57, p<.001), near visual acuity (r=-0.66, p<0.001), contrast sensitivity (r=0.62, p<.001) and critical print size (r=-0.60, p<.001).Conclusions: Our results indicate that the AI scores in a sample of people Portuguese people with visual impairment were in line with what has been found in other cultural contexts. The visual ability measured by the AI was correlated with visual function assessed by different visual tests, which shows that this instrument can be used with confidence.
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27.
  • Lima Ramos, Pedro, et al. (författare)
  • A review of capture-recapture methods and its possibilities in ophthalmology and vision sciences
  • 2020
  • Ingår i: Ophthalmic Epidemiology. - : Taylor & Francis. - 0928-6586 .- 1744-5086. ; 27:4, s. 310-324
  • Forskningsöversikt (refereegranskat)abstract
    • Epidemiological information is expected to be used to develop key aspects of eye care such as to control and minimise the impact of diseases, to allocate resources, to monitor public health actions, to determine the best treatment options and to forecast the consequence of diseases in populations. Epidemiological studies are expected to provide information about the prevalence and/or incidence of eye diseases or conditions. To determine prevalence is necessary to perform a cross-sectional screening of the population at risk to ascertain the number of cases.The aim of this review is to describe and evaluate capture-recapture methods (or models) to ascertaining the number of individuals with a disease (e.g. diabetic retinopathy) or condition (e.g. vision impairment) in the population.The review covers the fundamental aspects of capture-recapture methods that would enable non-experts in epidemiology to use it in ophthalmic studies. The review provides information about theoretical aspects of the method with examples of studies in ophthalmology in which it has been used. We also provide a problem/solution approach for limitations arising from the lists obtained from registers or other reliable sources.We concluded that capture-recapture models can be considered reliable to estimate the total number of cases with eye conditions using incomplete information from registers. Accordingly, the method may be used to maintain updated epidemiological information about eye conditions helping to tackle the lack of surveillance information in many regions of the globe.
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28.
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29.
  • Lima Ramos, Pedro, et al. (författare)
  • Cross-sectional study investigating the prevalence and causes of vision impairment in Northwest Portugal using capture–recapture: [SV] Tvärsnittsstudie som undersöker prevalensen och orsakerna till synnedsättning i nordvästra Portugal med hjälp av infångning-återfångst[PT] Estudo transversal que investiga a prevalência e as causas da deficiência visual no Noroeste de Portugal utilizando captura-recaptura
  • 2022
  • Ingår i: BMJ Open. - : BMJ Publishing Group Ltd. - 2044-6055. ; 12:9
  • Tidskriftsartikel (refereegranskat)abstract
    • Objectives: The aim of this study was to estimate the prevalence and causes of vision impairment (VI) in Portugal.Setting Information about people with VI was obtained from primary care centres, blind association (ACAPO) and from hospitals (the PCVIP study) in the Northwest of Portugal during a period spanning years 2014–2015. Causes of VI were obtained from hospitals.Participants Administrative and medical records of people with visual acuity in the better seeing eye of 0.5 decimal (0.30logMAR) or worse and/or visual field less than 20° were investigated. Capture–recapture with log-linear models was applied to estimate the number of individuals missing from lists of cases obtained from available sources.Primary and secondary outcome measures Log-linear models were used to estimate the crude prevalence and the category specific prevalence of VI.Results Crude prevalence of VI was 1.97% (95% CI 1.56% to 2.54%), and standardised prevalence was 1% (95% CI 0.78% to 1.27%). The age-specific prevalence was 3.27% (95% CI 2.36% to 4.90%), older than 64 years, 0.64% (95% CI 0.49% to 0.88%), aged 25–64 years, and 0.07% (95% CI 0.045% to 0.13%), aged less than 25 years. The female-to-male ratio was 1.3, that is, higher prevalence among females. The five leading causes of VI were diabetic retinopathy, cataract, age-related macular degeneration, glaucoma and disorders of the globe.Conclusions The prevalence of VI in Portugal was within the expected range and in line with other European countries. A significant number of cases of VI might be due to preventable cases and, therefore, a reduction of the prevalence of VI in Portugal seems possible. Women and old people were more likely to have VI and, therefore, these groups require extra attention. Future studies are necessary to characterise temporal changes in prevalence of VI in Portugal.No data are available. Raw data can be requested from the first author.
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30.
  • Lima Ramos, Pedro, et al. (författare)
  • Predicting participation of people with impaired vision in epidemiological studies
  • 2018
  • Ingår i: BMC Ophthalmology. - : BioMed Central (BMC). - 1471-2415. ; 18, s. 1-12
  • Tidskriftsartikel (refereegranskat)abstract
    • Background: The characteristics of the target group and the design of an epidemiologic study, in particular the recruiting methods, can influence participation. People with vision impairment have unique characteristics because those invited are often elderly and totally or partially dependent on help to complete daily activities such as travelling to study sites. Therefore, participation of people with impaired vision in studies is less predictable than predicting participation for the general population. Methods: Participants were recruited in the context of a study of prevalence and costs of visual impairment in Portugal (PCVIP-study). Participants were recruited from 4 Portuguese public hospitals. Inclusion criteria were: acuity in the better eye from 0.5 decimal (0.30logMAR) or worse and/or visual field of less than 20 degrees. Recruitment involved sending invitation letters and follow-up phone calls. A multiple logistic regression model was used to assess determinants of participation. The J48 classifier, chi-square and Fisher's exact tests were applied to investigate the possible differences between subjects in our sample. Results: Individual cases were divided into 3 groups: immediate, late and non-participants. A participation rate of 20% was obtained (15% immediate, 5% late). Factors positively associated with participation included years of education, annual hospital attendance, and intermediate visual acuity. Females and greater distance to the hospital were inversely associated with participation. Conclusion: In our study, a letter followed by a phone call was efficient to recruit a significant number of participants from a larger group of people with impaired vision. However, the improvement in participation observed after the phone call might not be cost-effective. People with low levels of education and women were more difficult to recruit. These findings need to be considered to avoid studies whose results are biased by gender or socioeconomic inequalities of their participants. Young subjects and those at intermediate stages of vision impairment, or equivalent conditions, may need more persuasion than other profiles.
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31.
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32.
  • Lima Ramos, Pedro (författare)
  • Studying prevalence using capture-recapture methods : visual impairment in Portugal
  • 2021
  • Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
    • Visual impairment (VI) due to eye diseases remains a significant healthproblem worldwide and, also, in Europe. There are an estimated 15 million peoplesuffering from moderate or severe visual impairment in Western Europe. VI has asignificant impact on the quality of life by reducing functional status and interferingwith the ability of the subject to maintain independence in a safe manner. Prevalenceof VI needs to be estimated regularly so that the progress of the vision health of apopulation can be evaluated and monitored. In addition, it is important to ascertainthe causes behind VI so that health programs can be designed to lower itsprevalence. There is currently a lack of epidemiological information about theprevalence and causes of VI in Portugal. Therefore, the aim of this thesis was todetermine the prevalence of VI in a large region Portugal using data from lists ofcases of VI.Capture-recapture models have been applied in several disciplines, asbiomedical sciences, epidemiology or ecology, to estimate the size of populations. Inparticular, they have been used to estimate the prevalence of several diseases orconditions. Developing these inferential models is of great importance to avoid thehigh costs and unreasonable time spending of cross-sectional studies. However,applying capture-recapture models is challenging, as they are very sensitive to listdependence and possible capture rates heterogeneity among subgroups of thepopulation. In particular, applying these models to human population samples isadditionally challenging, as in most epidemiologic studies only a small number oflists are available. There are two main differences between human and wildlifepopulations. First, human population lists generally have not a well-defined timeorder. Second, in wildlife studies there are often more trapping samples than inhuman population studies. In most epidemiologic surveys, only two to four lists areavailable. This can be problematic and is an additional difficulty when applyingcapture-recapture models in the context of human populations.The main objective of this work was to estimate the prevalence of VI usingcapture-recapture models. We estimated a crude prevalence of1.97%,95%CI=[1.56,2.54] to the Northwest of Portugal in the time period between2014 and 2015, specifically at the regions of Minho and Douro Litoral. Almost 2 ofevery 100 inhabitants of the Portuguese Northwest suffer from visual impairment.This prevalence value is in line with the values in some countries, particularly withSpain. Diabetic Retinopathy was the main cause (31%), followed by Cataract (15%),Age-related Macular Degeneration (14%) and Glaucoma (10%). This thesis provides asignificant contribution to the understanding of the CR methodology in human populations and for the knowledge of the epidemiological information about VI inPortugal.
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33.
  • Lincke, Alisa, 1989-, et al. (författare)
  • AI-Based Decision-Support System for Diagnosing Acanthamoeba Keratitis Using In Vivo Confocal Microscopy Images
  • 2023
  • Ingår i: Translational Vision Science & Technology. - : Association for research in vision and ophthalmology (ARVO). - 2164-2591. ; 12:11
  • Tidskriftsartikel (refereegranskat)abstract
    • Purpose: In vivo confocal microscopy (IVCM) of the cornea is a valuable tool for clinical assessment of the cornea but does not provide stand-alone diagnostic support. The aim of this work was to develop an artificial intelligence (AI)-based decision-support system (DSS) for automated diagnosis of Acanthamoeba keratitis (AK) using IVCM images.Methods: The automated workflow for the AI-based DSS was defined and implemented using deep learning models, image processing techniques, rule-based decisions, and valuable input from domain experts. The models were evaluated with 5-fold-cross validation on a dataset of 85 patients (47,734 IVCM images from healthy, AK, and other disease cases) collected at a single eye clinic in Sweden. The developed DSS was validated on an additional 26 patients (21,236 images).Results: Overall, the DSS uses as input raw unprocessed IVCM image data, successfully separates artefacts from true images (93% accuracy), then classifies the remaining images by their corneal layer (90% accuracy). The DSS subsequently predicts if the cornea is healthy or diseased (95% model accuracy). In disease cases, the DSS detects images with AK signs with 84% accuracy, and further localizes the regions of diagnostic value with 76.5% accuracy.Conclusions: The proposed AI-based DSS can automatically and accurately preprocess IVCM images (separating artefacts and sorting images into corneal layers) which decreases screening time. The accuracy of AK detection using raw IVCM images must be further explored and improved.Translational Relevance: The proposed automated DSS for experienced specialists assists in diagnosing AK using IVCM images.
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34.
  • Macedo, António Filipe, 1976-, et al. (författare)
  • An exploratory study of temporal integration in the peripheral retina of myopes
  • 2017
  • Ingår i: Proceedings of SPIE 10453. - : SPIE - International Society for Optical Engineering. - 9781510613843 - 9781510613836
  • Konferensbidrag (refereegranskat)abstract
    • The visual system takes time to respond to visual stimuli, neurons need to accumulate information over a time span in order to fire. Visual information perceived by the peripheral retina might be impaired by imperfect peripheral optics leading to myopia development. This study explored the effect of eccentricity, moderate myopia and peripheral refraction in temporal visual integration. Myopes and emmetropes showed similar performance at detecting briefly flashed stimuli in different retinal locations. Our results show evidence that moderate myopes have normal visual integration when refractive errors are corrected with contact lens; however, the tendency to increased temporal integration thresholds observed in myopes deserves further investigation.
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35.
  • Macedo, António Filipe, et al. (författare)
  • Anti-saccades in early stages of multiple sclerosis
  • 2015
  • Ingår i: Investigative Ophthalmology and Visual Science. - 0146-0404 .- 1552-5783. ; 56:7
  • Tidskriftsartikel (refereegranskat)abstract
    • Purpose: Eye movements disability is common finding in multiple sclerosis (MS) but the exact stage at which changes are visible is not clear. The aim of study was to assess if anti-saccade (AS) planning and execution are altered at early stages of the disease.Methods: A total of 48 participants with MS selected by a neurologist (JJC) at Hospital de Braga and 52 controls participated in this study. Inclusion criteria: relapsing-remitting course, EDSS≤3, 1 month or more without MS crisis, and normal or corrected visual acuity. Exclusion criteria (MS and Control): cognitive impairment, traumatic brain injury or stroke. The mean age in the MS group was 37y and 33y in the control group. Eye movements were monitored using a binocular infrared eyetracker running at 250Hz(RED250, SMI Gmb Germany), precision <0.4deg, stimuli were presented in a 22 monitor (Dell P2210). Code for running the experiment and data analysis was written using the Matlab (Mathworks Inc). Participants were seated in a room dim light at 74cm from the monitor and head movements were minimized by a headband. The task was to fixate, after a variable period between steady fixation and the stimulus of 1250ms or 1600ms, participants looked as quickly as possible for the opposite direction where the target (a 30x30mm cross) was presented (anti-saccade movement). Each subject performed 40 trails.Results: The main results were the proportion of the directional errors (wherein the participant voluntarily looked for the wrong side), and latencies for: i) anti-saccades, ii) pro-saccades (movement in the same direction of the stimulus) and iii) correction (reaction time that the participant takes from the error fixation until to start the movement). The mean number of errors was 28%(SD=19) in MS group and 16%(SD=11) in the control group, mean difference 12%, t(74)=3.83, p<.001. Anti-saccades latency was 330msec (SD=61) in the MS group and 294ms(SD=59) in the control group, mean difference 36ms, F(1,98)=10.99, p<.05. The mean of the correction latency value was 178ms(SD=111) in the MS group and 129ms(SD=107) in the control group with a mean difference of 49ms, F(1,98)=6, p<.05. No statistically significant differences were found in accuracy and pro-saccade latency between groups.Conclusions: This study shows that anti-saccades latency and errors are increased at early stages of multiple sclerosis. Anti-saccades might be a sensitive tool to assess functional status in people with this condition.
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36.
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37.
  • Macedo, António Filipe, 1976-, et al. (författare)
  • Fixation in Patients with Juvenile Macular Disease
  • 2007
  • Ingår i: Optometry and Vision Science. - 1040-5488 .- 1538-9235. ; 84:9, s. 852-858
  • Tidskriftsartikel (refereegranskat)abstract
    • Purpose. The instability of fixation with central scotoma has been mainly studied in patients with age-related macular diseases (MDs). However, early macular lesions can lead to different characteristics of fixation. The aim of this work was to study fixation in patients with juvenile MD.Methods. Eye movements of 10 patients and 10 controls were monitored during fixation. Visual fields were assessed by static perimetry to determine the extent of the field defects. Eye movements were separated into saccades and drifts, with fixation stability assessed by bivariate contour ellipse area (BCEA). To quantify the number and location of preferred retinal loci (PRL), the kernel density estimator and expectation maximization for mixtures of gaussians were used.Results. Patients have worse fixation stability than controls and large BCEAs resulted in more than one PRL. It was found that central field defects (10°) have negative correlation with the size of BCEA. In addition, the meridian of saccades during fixation was correlated with the meridian inter-PRL.Conclusions. Patients with juvenile MDs have large BCEAs, frequently associated with two PRL. Similar results had been found for patients with age-related MDs. Also, the meridian of involuntary saccades during fixation was found to be correlated with the location of PRLs, suggesting a useful role of these movements in alternating between them.
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38.
  • Macedo, António Filipe, et al. (författare)
  • Investigating unstable fixation in patients with macular disease
  • 2011
  • Ingår i: Investigative Ophthalmology and Visual Science. - : Association for Research in Vision and Ophthalmology (ARVO). - 0146-0404 .- 1552-5783. ; 52:3, s. 1275-1280
  • Tidskriftsartikel (refereegranskat)abstract
    • Purpose.: To assess the effect on visual acuity of compensating fixation instability by controlling retinal image motion in people with macular disease.Methods.: Ten patients with macular disease participated in this study. Crowded and noncrowded visual acuity were measured using an eye tracking system to compensate for fixation instability. Four conditions, corresponding to four levels of retinal image motion, were tested: no compensation (normal motion), partial compensation (reduced motion), total compensation (no motion), and overcompensation (increased motion). Fixation stability and the number of preferred retinal loci were also measured.Results.: Modulating retinal image motion had the same effect on crowded and noncrowded visual acuity (P = 0.601). When fixation instability was overcompensated, acuity worsened by 0.1 logMAR units (P < 0.001) compared with baseline (no compensation) and remained equal to baseline for all other conditions.Conclusions.: In people with macular disease, retinal image motion caused by fixation instability does not reduce either crowded or noncrowded visual acuity. Acuity declines when fixation instability is overcompensated, showing limited tolerance to increased retinal image motion. The results provide evidence that fixation instability does not improve visual acuity and may be a consequence of poor oculomotor control.
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39.
  • Macedo, António Filipe, Senior Lecturer, 1976-, et al. (författare)
  • Predictors of problems reported on the EQ-5D-3L dimensions among people with impaired vision in northern Portugal
  • 2022
  • Ingår i: Health and Quality of Life Outcomes. - : BioMed Central (BMC). - 1477-7525. ; 20:1
  • Tidskriftsartikel (refereegranskat)abstract
    • Background:The EQ-5D index often fails to detect the effect of ophthalmic diseases and sight loss. Investigating predictors of individual EQ-5D health dimensions might reveal the underlying reasons. The aim of this study was to investigate predictors of health dimension ratings obtained with the EQ-5D-3L from participants with impaired vision representing a spectrum of eye diseases.Methods: Observational cross-sectional study with participants recruited at four public hospitals in Portugal. Outpatients with visual acuity of 0.30 logMAR(6/12) or worse in the better-seeing eye were invited to participate. Participants completed two instruments: the EQ-5D-3L (measures participants’ perceived health-related quality-of-life) and the Massof Activity Inventory (measures visual ability–ability to perform vision-related activities). This study used logistic regression models to identify factors associated with responses to the EQ-5D-3L.Results: The study included 492 participants, mean age 63.4 years (range = 18–93), 50% females. The most common diagnosis was diabetic retinopathy (37%). The mean visual acuity in the better seeing eye was 0.65 logMAR (SD = 0.48) and the mean visual ability was 0.62 logits (SD = 2.04), the correlation between the two was r = − 0.511 (p < 0.001). Mobility and self-care were the health dimensions with the fewest problems (1% reported extreme problems), anxiety and depression the dimension with the most problems (24% reported extreme problems). ROC curve analysis showed that the EQ-5D index was a poor predictor of cases of vision impairment whilst visual ability given was a good predictor of cases of vision impairment. Visual ability was an independent predictor of the response for all dimensions, higher ability was always associated with a reduced odds of reporting problems. The odds of reporting problems were increased for females in 3 out of 5 dimensions. Comorbidities, visual acuity and age-category were predictors of the odds of reporting problems for one dimension each.Conclusions: The odds of reporting problems for the five health dimensions of the EQ-5D-3L were strongly influenced by the ability to perform vision-related activities (visual ability). The EQ-5D index showed poor performance at detecting vision impairment. These findings are informative and relevant for the clinic and for research evaluating the impact of eye diseases and disease treatments in ophthalmology.
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40.
  • Macedo, António Filipe, et al. (författare)
  • Smartphones in visual impairment
  • 2014
  • Ingår i: Investigative Ophthalmology and Visual Science. - 0146-0404 .- 1552-5783. ; 55:13
  • Tidskriftsartikel (refereegranskat)abstract
    • Purpose We have previously shown that electronic devices can be used by people with relatively low visual acuity and contrast sensitivity. The aim of this study was to determine if people with visual impairment use smartphones to compensate their visual deficits.Methods An online survey was advertised to people with visual impairment using personal contacts, social media and online discussion groups. This survey was administered in two languages: English and Portuguese. The first author is fluent in both languages and ensured accurate translation. The questionnaire was designed to collect basic demographic information and self-reported cause of visual impairment. Participants were asked to specify whether they used smartphones, and if so which operating system they used, what they used the device for, and which accessibility functions they used.Results In total 131 responses were obtained: 75 to the English and 56 to the Portuguese survey. 93% of the respondents were younger than 64 years and 25% had no perception of light. From the total number of 131 respondents, 101 used smartphone. Of these, 57% used an Apple OS, 22% used Android and 15% used Symbian. 98% of smartphone users made phone calls with their device and sending text messages was reported by 93%. Internet navigation was used by 84%, photo capabilities were used by 53% to help them to see and by 73% for other purposes. 80% also used apps on their device. Speech navigation was used by 67% of respondents, ability to enlarge print was used by 58% and a large screen was important to 40%. Font type and contrast changes were less commonly used. Only 14% received information about these devices from a vision care professional. Other sources included online search, recommendations from friends or blind associations.Conclusions Smartphones are widely used by people with visual impairment. The current accessibility features such as speech navigation and large print allow people with visual impairment to use of these devices not only as phones but also as an electronic low vision aid.
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41.
  • Macedo, António Filipe, et al. (författare)
  • Temporal Processing in the Peripheral Retina
  • 2012
  • Ingår i: Investigative Ophthalmology and Visual Science. - 0146-0404 .- 1552-5783. ; 53:14
  • Tidskriftsartikel (refereegranskat)abstract
    • Purpose: There is an increasing number of reports in the literature about the possible influence of the peripheral refraction in myopia development. The aim of this work was to determine whether the peripheral refractive differences lead to changes in visual performance. We used a forced choice procedure to assess the speed and accuracy (visual processing) of people with and without myopia at detecting the direction of a Gabor patch presented at different retinal locations. Methods: Visual processing was measured twice in random order at 6 retinal locations: 10, 20 and 30 degrees eccentricity at the temporal and at the nasal retina. We tested the dominant eye of 8 adults (aged 19 to 33 years) with moderate myopia (spherical equivalent ranging from -4.25 to -2.00 D) and 8 age-matched adults without myopia (spherical equivalent from -0.63 to 0.75 D). Participants’ task was to report via bottom press whether the Gabor patch, with suprathreshold contrast and spatial frequency, was tilted 30º to the right or to the left. The target was preceded by a 50 msec duration cue, exposed for variable periods of 10, 30, 60, 90 and 140 msec, selected in random order, and followed by a noise mask until response was given. For each block, processing time was determined using the method of constant stimuli based in 400 trials per retinal location (80 trials per exposure). Threshold was defined as the exposure time yielding 75% of correct responses; results were analysed using linear mixed models (SPSS, v18). Results: The mean processing time in the group with myopia was 73 msec and in the group without myopia was 66 msec; the difference between groups was not statistically significant (p = 0.087). There was a statistically significant difference between the nasal and temporal retina, mean difference was 13 msec (p = 0.002) with smaller processing time in the nasal retina. Conclusions: For the type of paradigm used in this study, there was no difference in processing time of the peripheral retina between people with and people without myopia. Despite extensive reports in the literature about different refraction patterns in this study we found evidences that this does not translate into functional changes.
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42.
  • Macedo, António Filipe, 1976-, et al. (författare)
  • The effect of retinal image slip on peripheral visual acuity
  • 2008
  • Ingår i: Journal of Vision. - : Association for Research in Vision and Ophthalmology (ARVO). - 1534-7362. ; 8:14, s. 1-11
  • Tidskriftsartikel (refereegranskat)abstract
    • Abstract Retinal image slip promoted by fixational eye movements prevents image fading in central vision. However, in the periphery a higher amount of movement is necessary to prevent this fading. We assessed the effect of different levels of retinal image slip in peripheral vision by measuring peripheral visual acuity (VA), with and without crowding, while modulating retinal image slip by using gaze-linked stimuli. Measurements were carried out at four isoeccentric positions at 5 and at 10 degrees eccentricity. Gaze position was monitored throughout using an infrared eyetracker. The target was presented for up to 500 msec, either with no retinal image slip, with reduced retinal slip, or with increased retinal image slip. Without crowding, peripheral visual acuity improved with increased retinal image slip compared with the other two conditions. In contrast to the previous result, under crowded conditions, peripheral visual acuity decreased markedly with increased retinal image slip. Therefore, the effects of increased retinal image slip are different for simple (noncrowded) and more complex (crowded) visual tasks. These results provide further evidence for the importance of fixation stability on complex visual tasks when using the peripheral retina.
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43.
  • Macedo, António Filipe, et al. (författare)
  • Visual and health outcomes, measured with the activity inventory and the EQ-5D, in visual impairment
  • 2017
  • Ingår i: Acta Ophthalmologica. - : Wiley-Blackwell. - 1755-375X .- 1755-3768. ; 95:8, s. e783-e791
  • Tidskriftsartikel (refereegranskat)abstract
    • PurposeGeneric instruments to assess health utilities can be used to express the burden of health problems in widely used indexes. That is in contrast with what can be obtained with condition-specific instruments, outcomes are very specific and difficult to compare across conditions. The purpose of this study was to assess health and visual outcomes and its determinants in patients with visual impairment (VI) using the EQ-5D-3L and the Activity Inventory (AI).MethodsParticipants were recruited in different hospitals during the PCVIP-study. A total of 134 patients with acuity 0.30 logMAR or less in the better eye were interviewed. The AI includes 46 goals split between three objectives: social functioning, recreation and daily living, and was used to measure visual ability. The EQ-5D consists of five questions covering one domain each and was used to provide a measure of health states. Responses to each domain were combined to produce a single individual index.ResultsThe AI and the EQ-5D-3L showed enough discriminatory power between VI levels (p < 0.001), and their results were strongly correlated r(134) = 0.825, (p < 0.001). Explanatory factors for visual ability were level of VI in better eye, age and gender, R2 = 0.43, (p < 0.001). Explanatory factors for the EQ-5D-3L were level of VI in the better eye, comorbidities and gender, R2 = 0.36, (p < 0.001).ConclusionOur results showed that the EQ-5D-3L is useful when characterizing the burden of VI and to compute, when necessary, quality-adjusted-life-years (QALY) changes due to VI. However, it is important to consider that the EQ-5D-3L uses a coarse response scale, assesses a limited spectrum of domains and is influenced by comorbidities. This might limit its responsiveness to small changes in visual ability.
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44.
  • Marisa, Ferreira, 1992-, et al. (författare)
  • Using endogenous saccades to characterize fatigue in multiple sclerosis
  • 2017
  • Ingår i: Multiple Sclerosis and Related Disorders. - : Elsevier. - 2211-0348 .- 2211-0356. ; 14, s. 16-22
  • Tidskriftsartikel (refereegranskat)abstract
    • PurposeMultiple Sclerosis (MS) is likely to cause dysfunction of neural circuits between brain regions increasing brain working load or a subjective overestimation of such working load leading to fatigue symptoms. The aim of this study was to investigate if saccades can reveal the effect of fatigue in patients with MS.MethodsPatients diagnosed with MS (EDSS<=3) and age matched controls were recruited. Eye movements were monitored using an infrared eyetracker. Each participant performed 40 trials in an endogenous generated saccade paradigm (valid and invalid trials). The fatigue severity scale (FSS) was used to assess the severity of fatigue. FSS scores were used to define two subgroups, the MS fatigue group (score above normal range) and the MS non-fatigue. Differences between groups were tested using linear mixed models.ResultsThirty-one MS patients and equal number of controls participated in this study. FSS scores were above the normal range in 11 patients. Differences in saccade latency were found according to group (p<0.001) and trial validity (p=0.023). Differences were 16.9 ms, between MS fatigue and MS non-fatigue, 15.5 ms between MS fatigue and control. The mean difference between valid and invalid trials was 7.5 ms. Differences in saccade peak velocity were found according to group (p<0.001), the difference between MS fatigue and control was 22.3°/s and between MS fatigue and non-fatigue was 12.3°/s. Group was a statistically significant predictor for amplitude (p<0.001). FSS scores were correlated with peak velocity (p=0.028) and amplitude (p=0.019).ConclusionConsistent with the initial hypothesis, our study revealed altered saccade latency, peak velocity and amplitude in patients with fatigue symptoms. Eye movement testing can complement the standard inventories when investigating fatigue because they do not share similar limitations. Our findings contribute to the understanding of functional changes induced by MS and might be useful for clinical trials and treatment decisions.
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45.
  • Markoulli, Maria, et al. (författare)
  • BCLA CLEAR Presbyopia : Epidemiology and impact
  • 2024
  • Ingår i: Contact lens & anterior eye. - : Elsevier. - 1367-0484 .- 1476-5411.
  • Tidskriftsartikel (refereegranskat)abstract
    • The global all-ages prevalence of epidemiologically-measured 'functional' presbyopia was estimated at 24.9% in 2015, affecting 1.8 billion people. This prevalence was projected to stabilise at 24.1% in 2030 due to increasing myopia, but to affect more people (2.1 billion) due to population dynamics. Factors affecting the prevalence of presbyopia include age, geographic location, urban versus rural location, sex, and, to a lesser extent, socioeconomic status, literacy and education, health literacy and inequality. Risk factors for early onset of presbyopia included environmental factors, nutrition, near demands, refractive error, accommodative dysfunction, medications, certain health conditions and sleep. Presbyopia was found to impact on quality-of-life, in particular quality of vision, labour force participation, work productivity and financial burden, mental health, social wellbeing and physical health. Current understanding makes it clear that presbyopia is a very common age-related condition that has significant impacts on both patient-reported outcome measures and economics. However, there are complexities in defining presbyopia for epidemiological and impact studies. Standardisation of definitions will assist future synthesis, pattern analysis and sense-making between studies.
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46.
  • Marques, Ana Patrícia, et al. (författare)
  • Diffusion of anti-VEGF injections in the Portuguese National Health System
  • 2015
  • Ingår i: BMJ Open. - : BMJ Publishing Group Ltd. - 2044-6055. ; 5:11, s. 11-
  • Tidskriftsartikel (refereegranskat)abstract
    • ObjectivesTo analyse the temporal and geographical diffusion of antivascular endothelial growth factor (anti-VEGF) interventions, and its determinants in a National Health System (NHS).SettingNHS Portuguese hospitals.ParticipantsAll inpatient and day cases related to eye diseases at all Portuguese public hospitals for the period 2002–2012 were selected on the basis of four International Classification of Diseases 9th revision, Clinical Modification (ICD-9-CM) codes for procedures: 1474, 1475, 1479 and 149.Primary and secondary outcome measuresWe measured anti-VEGF treatment rates by year and county. The determinants of the geographical diffusion were investigated using generalised linear modelling.ResultsWe analysed all hospital discharges from all NHS hospitals in Portugal (98 408 hospital discharges corresponding to 57 984 patients). National rates of hospitals episodes for the codes for procedures used were low before anti-VEGF approval in 2007 (less than 12% of hospital discharges). Between 2007 and 2012, the rates of hospital episodes related to the introduction of anti-VEGF injections increased by 27% per year. Patients from areas without ophthalmology departments received fewer treatments than those from areas with ophthalmology departments. The availability of an ophthalmology department in the county increased the rates of hospital episodes by 243%, and a 100-persons greater density per km2 raised the rates by 11%.ConclusionsOur study shows a large but unequal diffusion of anti-VEGF treatments despite the universal coverage and very low copayments. The technological innovation in ophthalmology may thus produce unexpected inequalities related to financial constraints unless the implementation of innovative techniques is planned and regulated
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47.
  • Marques, Ana Patricia, et al. (författare)
  • Emergence of intravitreal injections in a National Health System : 2002-2012
  • 2014
  • Ingår i: Investigative Ophthalmology and Visual Science. - 0146-0404 .- 1552-5783. ; 55:13
  • Tidskriftsartikel (refereegranskat)abstract
    • Purpose Intravitreal injections of antivascular endothelial growth factor (anti-VEGF) are an innovative procedure with well-proven benefits to preserve vision in certain eye conditions. The aim of this study was to examine the diffusion of this treatment in the Portuguese National Health System.Methods We used a database of all in-patient and day cases stays from all Portuguese public hospitals during period 2002-2012. We selected cases based on four procedures, ICD-9-CM codes: 1414, 1475, 1479, 149. Given that these procedures are not specific for intravitreal injections it is likely that our results captured cases that are not anti-VEGF injections. Because we were only interested in the diffusion of new anti-VEGF treatments we included years 2002-2005 as baseline because during that period drugs anti-VEGF were not licenced. We calculated absolute values, yearly rates of episodes and rates of patients treated per 100,000 habitants.Results Our final sample included 98,408 episodes, 52% performed in men. The total number of episodes increased from 1,815 in 2002 to 25,106 in 2012 (mean annual increase of 32%). These values corresponded to an increase in ratios per 100,000 from 17.4 to 238.77. The highest increase was observed between 2007 and 2009 with an increase of 337%. The number of treated patients was six times higher in 2012 with 11,937 treated compared with 1,561 in 2002 (mean annual increase of 24%). The highest increase was also observed between 2006 and 2009. In 2012, 86.2% of the procedures were performed as day cases, representing an increase of 78.3% as compared to 2002. The percentage of patients older than 60 years increased from 60% in 2002 to 80% in 2012. Five diagnoses (See Figure: wet AMD, diabetic macular oedema, oedema of the retina, retinal neovascularization and non-specific AMD) were associated with 73% of these procedures in 2012, in contrast with only 16% in 2002.Conclusions The number of procedures grew exponentially since anti-VGEF treatments were approved. The aging of the population and the expected growth in conditions such as diabetes and AMD are likely to increase the demand for these procedures in years to come. These factors are likely to impose tremendous challenges to health services. That will happen not only due to the price of the procedures but also for number of physicians and other staff needed in Ophthalmology departments. View
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48.
  • Marques, Ana Patricia, et al. (författare)
  • Estimating the cost of visual impairment : initial results
  • 2015
  • Ingår i: Investigative Ophthalmology and Visual Science. - 0146-0404 .- 1552-5783. ; 56:7
  • Tidskriftsartikel (refereegranskat)abstract
    • Purpose: Vision loss can have a substantial human and economic impact on individuals and society that include disability, loss of productivity and reduction in quality of life. The purpose of this study was to estimate economic burden of visual impairment in Portugal.Methods: A prevalence-based cost of illness approach was adopted to estimate costs of vision impairment. We estimated direct medical costs and indirect economic costs. Direct medical hospital costs were determined using a bottom up approach. For those meeting the inclusion criteria (visual acuity of 20/40 or 0.5decimal or worse in the better eye and/or visual field of less than 20deg) we estimated direct costs by collecting information from administrative records that included: physician’s office visits, emergency and outpatient visits. We developed a survey based in parts of the annotated cost questionnaire-HERU Discussion Paper N.03/01 (UK Working Party on Patient Costs) and the Service Receipt Inventory-European Version. Using the questionnaire that we developed, in face-to-face interviews, we collect direct medical expenditures supported by patients that included: costs with medical prescriptions, low vision aids and devices. With the same questionnaire we collected information for indirect costs calculations. Indirect costs were calculated by estimating the value of productivity losses including employment participation, absenteeism and caregiver costs.Results: Results presented here correspond to 442 patients that met the inclusion criteria. The four main causes of visual impairment in this sample were Diabetic Retinopathy, Cataract, Glaucoma and Age-related macular degeneration. Direct medical hospital costs were accountable for 12% of total costs calculated. Patient expenditures represented 25% of expenses with visual impairment and indirect costs corresponded to 63% of the total. From this data we estimated that the average annual direct cost per patient with VI was 958 euro and average annual indirect cost was 1655 euro.Conclusions: With the instruments and methodology that was adopted we were able quantify direct medical hospital costs as well as indirect costs of visual impairment. Results of this study show that more than half of the costs with VI are indirect. This highlights that particular attention should be given to costs that arise for individuals with vision loss.
  •  
49.
  • Marques, Ana Patricia, et al. (författare)
  • Productivity Losses and Their Explanatory Factors Amongst People with Impaired Vision
  • 2019
  • Ingår i: Ophthalmic Epidemiology. - : Taylor & Francis Group. - 0928-6586 .- 1744-5086. ; 26:6, s. 378-392
  • Tidskriftsartikel (refereegranskat)abstract
    • Purpose: To estimate productivity losses amongst people with impaired vision in Portugal and to investigate explanatory factors associated with non-participation in the labour market.Methods: A total of 546 visually impaired individuals participated in face-to-face interviews. Participants were asked about their workforce participation to determine productivity (employment status questionnaire), their health-related quality of life – HRQoL (EQ-5D) and their visual acuity and visual ability (Activity Inventory). Productivity losses included absenteeism and reduction in workforce participation. Logistic regression was used to determine independent factors associated with participation in the labour market.Results: From the 546 participants, 50% were retired, 47% were of working age and 3% were students. The employment rate was 28%, and the unemployment rate was 21% for the working age sample. For those of working age, productivity losses were estimated at €1.51 million per year, mean of €5496 per participant. The largest contributor to productivity losses was reduced workforce participation, estimated from 159 early retired or unemployed participants. After controlling for visual acuity and ability, younger individuals, with more years of education, without comorbidities and high HRQoL had a higher probability of being employed.Conclusions: Our findings show a high unemployment rate and high productivity losses amongst people with impaired vision. The probability of being employed was associated with education, HRQoL and comorbidities. We speculate that promoting education and health through effective visual rehabilitation programs may help to increase participation in the labour market. These findings can inform decisions to intervene to reduce the burden of vision loss.
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50.
  • Marques, Ana Patricia, et al. (författare)
  • The use of informal care by people with vision impairment
  • 2018
  • Ingår i: PLOS ONE. - : Public Library of Science. - 1932-6203. ; 13:6
  • Tidskriftsartikel (refereegranskat)abstract
    • PurposeTo estimate and characterize the use of informal care by people with vision impairment in Portugal.MethodsA total of 546 visually impaired individuals were recruited from Portuguese hospitals. Clinical information was obtained from medical records, socio-demographic details and informal care use were collected during face-to-face interviews. In addition, participants responded to a functional vision questionnaire (activity inventory) to assess their visual ability. Logistic regression was used to determine independent factors associated with informal care use and linear regression was used to determine independent predictors of intensity of informal care use.ResultsInformal care was reported by 39.6% of the participants. The probability of reporting informal care was higher in non-married, those with comorbidities, with lower visual ability and worse visual acuity. The median number of caregivers’ hours per year was 390 (mean = 470; 95%CI = 488–407), which represent a median opportunity cost of €2,586. Visual ability was the only independent predictor of number of hours of informal care received.ConclusionsInformal care was frequently used by individuals with impaired vision. Improving visual ability of people with impaired vision when performing valued activities may reduce the burden of visual loss at personal and societal level. This could be achieved with person-centred visual rehabilitation.
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