| 1. |
- Agardh, Elisabet, et al.
(författare)
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Stable refraction and visual acuity in diabetic patients with variable glucose levels under routine care
- 2011
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Ingår i: Acta Ophthalmologica. - : Wiley-Blackwell. - 1755-375X .- 1755-3768. ; 89:2, s. 107-110
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Tidskriftsartikel (refereegranskat)abstract
- PURPOSE: To investigate how refraction and visual acuity may vary in patients with diabetes under routine care.METHODS: Fifty-three eyes of 53 patients with various degrees of diabetic retinopathy were examined prospectively on four different occasions within a month. Refraction, best-corrected visual acuity (expressed as logMAR score) and blood glucose were measured on each occasion. Intraindividual variability was calculated as the range between the highest and lowest measurements. Associations between blood glucose levels and each of the other variables were tested by linear regression analysis for each patient.RESULTS: Refraction was completely stable in 43 patients and changed only slightly in 10, in whom the mean intraindividual variability of the spherical equivalent was 0.4 dioptres. Visual acuity test results were also highly reproducible. Mean intraindividual variability in visual acuity was 0.08 logMAR. Mean haemoglobin A1c (HbA1c) was 7.3 ± 1.5% but individual blood glucose levels ranged from 2.8 to > 22.2 mmol/l. Intraindividual variability ranged from 0.5 to 18.1 mmol/l, with a median of 6.0 mmol/l for the entire group. There were no associations between refraction or visual acuity and blood glucose levels or inter- or intraindividual glucose variations.CONCLUSION: Refraction and visual acuity test results were highly reproducible and stable in patients with reasonably well controlled diabetes but variable blood glucose levels under routine care.
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| 2. |
- Andersson, Sabina, et al.
(författare)
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Comparison of clinicians and an artificial neural network regarding accuracy and certainty in performance of visual field assessment for the diagnosis of glaucoma.
- 2013
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Ingår i: Acta Ophthalmologica. - : Wiley. - 1755-3768 .- 1755-375X. ; 91:5, s. 413-417
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Tidskriftsartikel (refereegranskat)abstract
- Purpose: To compare clinicians and a trained artificial neural network (ANN) regarding accuracy and certainty of assessment of visual fields for the diagnosis of glaucoma. Methods: Thirty physicians with different levels of knowledge and experience in glaucoma management assessed 30-2 SITA Standard visual field printouts that included full Statpac information from 99 patients with glaucomatous optic neuropathy and 66 healthy subjects. Glaucomatous eyes with perimetric mean deviation values worsethan -10 dB were not eligible. The fields were graded on a scale of 1-10, where 1 indicated healthy with absolute certaintyand 10 signified glaucoma; 5.5 was the cut-off between healthy and glaucoma. The same fields were classified by a previously trained ANN. The ANN output was transformed into a linear scale that matched the scale used in the subjective assessments. Classification certainty was assessed using a classification error score. Results: Among the physicians, sensitivity ranged from 61% to 96% (mean 83%) and specificity from 59% to 100% (mean 90%). Our ANN achieved 93% sensitivity and 91% specificity, and it was significantly more sensitive than the physicians (p < 0.001) at a similar level of specificity. The ANN classification error score was equivalent to the top third scores of all physicians, and the ANN never indicated a high degree of certainty for any of its misclassified visual field tests. Conclusion: Our results indicate that a trained ANN performs at least as well as physicians in assessments of visual fields for the diagnosis of glaucoma.
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| 3. |
- Bengtsson, Boel, et al.
(författare)
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Performance of time-domain and spectral-domain Optical Coherence Tomography for glaucoma screening.
- 2010
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Ingår i: Acta Ophthalmologica. - : Wiley. - 1755-3768 .- 1755-375X. ; :Nov
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Tidskriftsartikel (refereegranskat)abstract
- Purpose: To investigate the measures of validity for selective or population screening of the time-domain Stratus and the spectral-domain Cirrus Optical Coherence Tomography (OCT) imaging techniques in a population-based sample and in clinical glaucoma patients at different stages of glaucoma. Patients and methods: A random sample of 307 subjects living in two rural areas in southern Sweden, and a random sample of 394 clinical glaucoma patients were selected. A large battery of examinations, including Stratus and Cirrus OCT was performed. OCT retinal nerve fibre layer (RNFL) thickness analyses for average thickness, quadrant and clock-hour sectors were compared with normative significance limits available in the instruments. Results: The population-based sample included 129 healthy and nine glaucoma subjects, and the sample of clinical glaucoma patients included 138 patients. Specificity and positive predictive values were generally better with Stratus than for Cirrus, and sensitivity was generally better with Cirrus. With the average RNFL thickness parameter, Stratus reached 100% specificity and a positive predictive value of 100% and 68% sensitivity in the whole group of the clinical glaucoma patients, but sensitivity was only 28% among the earliest stage glaucoma patients. Sensitivity increased considerably when relying on the quadrant sector parameter, while specificity decreased only marginally. Conclusion: Stratus, with high specificity and positive predictive values, seemed to be best of choice for screening purposes, while Cirrus, with high sensitivity, was the better choice for early detection.
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| 4. |
- Bizios, Dimitrios, et al.
(författare)
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Machine learning classifiers for glaucoma diagnosis based on classification of retinal nerve fibre layer thickness parameters measured by Stratus OCT.
- 2010
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Ingår i: Acta Ophthalmologica. - : Wiley. - 1755-3768 .- 1755-375X. ; 88, s. 44-52
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Tidskriftsartikel (refereegranskat)abstract
- Abstract. Purpose: To compare the performance of two machine learning classifiers (MLCs), artificial neural networks (ANNs) and support vector machines (SVMs), with input based on retinal nerve fibre layer thickness (RNFLT) measurements by optical coherence tomography (OCT), on the diagnosis of glaucoma, and to assess the effects of different input parameters. Methods: We analysed Stratus OCT data from 90 healthy persons and 62 glaucoma patients. Performance of MLCs was compared using conventional OCT RNFLT parameters plus novel parameters such as minimum RNFLT values, 10th and 90th percentiles of measured RNFLT, and transformations of A-scan measurements. For each input parameter and MLC, the area under the receiver operating characteristic curve (AROC) was calculated. Results: There were no statistically significant differences between ANNs and SVMs. The best AROCs for both ANN (0.982, 95%CI: 0.966-0.999) and SVM (0.989, 95% CI: 0.979-1.0) were based on input of transformed A-scan measurements. Our SVM trained on this input performed better than ANNs or SVMs trained on any of the single RNFLT parameters (p
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| 5. |
- Edén, Ulla, et al.
(författare)
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Aniridia among children and teenagers in Sweden and Norway.
- 2008
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Ingår i: Acta Ophthalmologica. - : Wiley. - 1755-3768 .- 1755-375X. ; 86, s. 730-734
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Tidskriftsartikel (refereegranskat)abstract
- Purpose: To investigate patients under the age of 20 with aniridia in Sweden and Norway in order to estimate the prevalence of aniridia, to describe clinical signs and identify complications in the young, which will help improve diagnostic tools and treatment. Methods: A thorough search for patients with aniridia (of all ages) was performed. Sixty-two of the 181 patients were under the age of 20. Fifty-two of them were examined and they constituted the study population. Patient history was obtained and all participants underwent clinical ophthalmologic examination, including photography. Blood samples were taken for mutation analysis. Results: Epidemiological data are only based on the results in Sweden. The age-specific prevalence in Sweden was 1:47 000, male/female ratio was 0.57, mean age 12 years and median age 14 years. The proportion of sporadic cases including WAGR (Wilms tumour, Aniridia, Genitourinary abnormalities, Mental Retardation) and Gillespie syndrome (aniridia, cerebellar ataxia and mental retardation) was 48%. In the entire study population (Sweden and Norway), the mean visual acuity (VA) was 0.2 (range 0.04-0.9). We found VA < 0.3 in 80% and <0.1 in 18% of the patients. Twenty-two patients (42%) had one or more of the sight threatening complications such as cataract/lens luxation, corneal clouding or glaucoma. Conclusion: Descriptions of aniridia in the younger are rare. This study shows that aniridia seems to be more common than previously estimated and that some complications appear early in life. Watchfulness as regards these complications and regular examinations are essential even in the youngest.
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| 6. |
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| 7. |
- Gustavsson, Carin, et al.
(författare)
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Profile of intraocular tumour necrosis factor-α and interleukin-6 in diabetic subjects with different degrees of diabetic retinopathy.
- 2013
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Ingår i: Acta Ophthalmologica. - : Wiley. - 1755-3768 .- 1755-375X. ; 91:5, s. 445-452
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Tidskriftsartikel (refereegranskat)abstract
- Purpose: To assess and correlate the levels of inflammatory mediators in the eyes from non-diabetic and diabetic subjects without retinopathy (NDR), with non-proliferative diabetic retinopathy (NPDR) or with proliferative diabetic retinopathy (PDR) to corresponding erum levels. Methods: The levels of interleukin 1β, interleukin-6 (IL-6) and tumour necrosis factor-α (TNF-α) were analysed by an ELISA-mimicking technique in the vitreous from 26 diabetic subjects with active PDR and 27 non-diabetic subjects, or by a multiplex bead assay in the aqueous humour from 35 diabetic subjects with NDR/NPDR and 40 non-diabetic subjects. Intraocular protein production was estimated in vitreous specimens by calculating a vitreous/serum ratio. Results: In the vitreous, IL-6 was higher in diabetic [157.5 (25.0-1401.0) pg/ml; median (min-max)] than in non-diabetic subjects [44.0 (5.0-4425) pg/ml; p = 0.021]. The vitreous/serum ratio was high (55.5:1 and 16:1, respectively), suggesting intraocular production. TNF-α was lower in diabetic [18.0 (8.0-46.0) pg/ml] than in non-diabetic subjects [22.0 (13.0-47.0) pg/ml; p = 0.034], but the vitreous/serum ratio was elevated in both groups (2:1 and 3.4:1, respectively). TNF-α levels were higher in serum from diabetic subjects [9.0 (5.0-53.0) pg/ml versus 6.7 (3.0-11.0) pg/ml; p < 0.001]. Aqueous levels of inflammatory mediators did not differ between diabetic subjects with NDR/NPDR and non-diabetic subjects despite elevated TNF-α in serum [27.8 (6.8-153.7) pg/ml versus 16.4 (4.1-42.4) pg/ml; p = 0.021]. Conclusion: Intraocular inflammation seems to be involved in PDR but does not seem to be prominent in early retinopathy stages, i.e. NDR or NPDR. Diabetic subjects have an overall increased inflammatory activity compared to non-diabetic subjects, as demonstrated by increased serum levels of TNF-α.
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| 8. |
- Hammar, Björn, et al.
(författare)
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Dystrophia Helsinglandica : a new type of hereditary corneal recurrent erosions with late subepithelial fibrosis
- 2009
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Ingår i: Acta ophthalmologica. - : Wiley. - 1755-3768 .- 1755-375X. ; 87:6, s. 659-667
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Tidskriftsartikel (refereegranskat)abstract
- Purpose: To describe the phenotype of an autosomal-dominant corneal dystrophy with an early onset of recurrent corneal erosions and development of subepithelial fibrosis in the cornea, and also to exclude genetic linkage to known corneal dystrophies with autosomal-dominant inheritance and clinical resemblance. Methods: We describe the medical history and clinical findings in individuals from a seven-generation family with recurrent corneal erosions. A total of 43 individuals were evaluated by ophthalmological examination. Genomic DNA was prepared from peripheral blood and polymorphic microsatellite markers were analysed to study haplotypes surrounding genes causing corneal dystrophies with similar phenotypes. Results: Erosive symptoms usually lasted for between 1 and 10 days. By the age of 7 almost all of the affected individuals suffered from recurrent corneal erosions. The attacks generally declined in frequency and intensity from the late 20s, but all examined individuals had developed subepithelial fibrosis by the age of 37. The fibrosis generally started in the mid periphery and was followed in some family members by central fibrosis and the development of gelatinous superficial elevations. Only a marginal reduction of visual acuity was seen in a few individuals. The affected individuals did not share haplotypes for genetic microsatellite markers surrounding genes that are known to cause autosomal-dominant corneal dystrophies. Conclusion: We describe a new type of autosomal-dominant corneal disorder with recurrent corneal erosions and subepithelial fibrosis not significantly affecting visual acuity.
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| 9. |
- Hammar, Björn, et al.
(författare)
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Dystrophia Smolandiensis: a novel morphological picture of recurrent corneal erosions
- 2010
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Ingår i: Acta Ophthalmologica. - : Wiley. - 1755-3768 .- 1755-375X. ; 88:4, s. 394-400
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Tidskriftsartikel (refereegranskat)abstract
- Purpose: The aim of this study was to describe morphological changes in Dystrophia Smolandiensis, a corneal disease that is characterized by recurrent corneal erosive episodes and the formation of central corneal keloid-like opacities in approximately half of those affected. Methods: The corneas of seven affected individuals were examined using in-vivo confocal microscopy. Specimens of one primary corneal graft, one regraft and one biopsied keloid-like region - all obtained from members of a large family with the disease - were re-examined with a light microscope. Sections were stained with Congo red and analysed immunohistochemically for fibronectin and S100A4. Results: Light microscopic examination revealed epithelial hyperplasia, absence of Bowman's layer and subepithelial fibrosis. Fibronectin was expressed in the area of subepithelial fibrosis, and the keratocytes in this area generally expressed S100A4. The biopsy specimen stained positive for Congo red, suggesting an amyloid deposit. In-vivo confocal microscopy confirmed epithelial abnormalities, loss of Bowman's layer and significant alterations of the subbasal nerve plexus in affected individuals. Conclusion: The morphological picture in Dystrophia Smolandiensis is novel for a condition dominated by recurrent corneal erosions at the clinical level. Although no single morphological feature unique to the disease could be found, the general morphological pattern of pathology (true keloid formation, absence of Bowman's layer, subepithelial fibrosis and abnormal subbasal nerves) probably reflects a novel phenotypic expression of the healing response to recurrent erosion of the corneal epithelium. However, the pathogenesis of Dystrophia Smolandiensis remains to be elucidated fully.
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| 10. |
- Heijl, Anders, et al.
(författare)
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Rates of visual field progression in clinical glaucoma care.
- 2013
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Ingår i: Acta Ophthalmologica. - : Wiley. - 1755-3768 .- 1755-375X. ; 91:5, s. 406-412
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Tidskriftsartikel (refereegranskat)abstract
- Purpose: To investigate rates of visual field progression and factors associated with progression rate in open-angle glaucoma in clinical glaucoma care. Methods: We performed a retrospective chart review of all patients with manifest primary open-angle glaucoma (POAG) and pseudoexfoliation glaucoma (PEXG) followed ≥ 5 years with ≥5 SITA Standard fields. Exclusion criteria were minimal. Demographics, intraocular pressure values (IOP), treatment and treatment changes, and visual field (VF) data were recorded. VF progression rates were calculated as slopes of mean deviation (MD) over time. Results: Five hundred and eighty-three patients were eligible. Three hundred and sixty-seven (62%) had POAG and 221 (38%) PEXG. Median MD at study start was -10.0 dB. Mean follow-up time was 7.8 years (SD ± 1.2); mean number of VF tests was 8.9 (SD ± 2.8). Progression rates varied very much among patients with a mean of -0.80 dB/year (SD ± 0.82; median rate, -0.62), and 5.6% of patients progressed at rates worse than -2.5 dB per year A negative slope of MD values was observed in 89% of patients. Mean IOP of all visits decreased over the study period from 20.15 to 18.10 mmHg. Higher age and mean IOP, and more intensive treatment were associated with more rapid progression, while PEXG and IOP variation were not, if treatment intensity was taken into account. Conclusion: Rates of visual field progression in manifest glaucoma with field loss in ordinary clinical care were highly variable. Progression rates rapid enough to influence quality of life were common.
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| 11. |
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| 12. |
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| 13. |
- Hellgren, Karl-Johan, 1971-, et al.
(författare)
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Functional and structural change in diabetic eyes. Interim results from an ongoing longitudinal prospective study
- 2013
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Ingår i: Acta Ophthalmologica. - : Wiley-Blackwell. - 1755-375X .- 1755-3768. ; 91:7, s. 672-677
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Tidskriftsartikel (refereegranskat)abstract
- Purpose: To presents results after 18months of follow-up of a longitudinal study aiming at exploring the correlation between diabetic retinal vascular lesions and functional change.Methods: Patients were consecutively recruited from attendees to the screening program for diabetic retinopathy. Subjects are followed every sixth month for the first 3years and thereafter annually up to 5years. Progression of diabetic retinopathy is evaluated using the Early Treatment Diabetic Retinopathy Study (ETDRS) scale and improvement/deterioration in visual fields by predefined significance limits for change.Results: Of 81 subjects, with no/mild/moderate diabetic retinopathy included, 76 have passed the 18-month visit. At that time, retinal progression by two steps according to the ETDRS scale had occurred in two subjects. Visual acuity was -0.14 logMAR and had decreased with two letters (0.04 logMAR) (p<0.001) from baseline. The global visual field index mean deviation was almost unchanged with a negligible improvement of 0.03dB (p=0.79). In 21 subjects, repeated significant deterioration was seen in 10% of all points tested in the field, while almost no improved points were noted. The two subjects with retinal progression were not among those 21 with indication of perimetric progression.Conclusions: This is, to our knowledge, the first longitudinal study evaluating change of visual fields in a representative diabetic cohort with no or mild/moderate retinopathy. In this interim report, we demonstrate deteriorated perimetric sensitivity in subjects already at 18months of follow-up. The results will have implications for evaluating change in visual function in future clinical trials.
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| 14. |
- Lövestam Adrian, Monica, et al.
(författare)
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Multifocal electroretinography amplitudes increase after photocoagulation in areas with increased retinal thickness and hard exudates.
- 2010
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Ingår i: Acta Ophthalmologica. - : Wiley. - 1755-3768 .- 1755-375X. ; 88, s. 188-192
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Tidskriftsartikel (refereegranskat)abstract
- Abstract. Purpose: This study aimed to evaluate local response on multifocal electroretinography (mfERG) and to assess retinal thickness with optical coherence tomography (OCT) after focal laser treatment in areas with retinal oedema and exudates in patients with diabetic retinopathy. Methods: Twelve diabetes patients (aged 60 +/- 14 years, diabetes duration 16 +/- 8 years) treated with focal or grid photocoagulation in areas with retinal oedema and/or exudates underwent mfERG and OCT before and 3 months after treatment. The average thickness (in mum) in any of the nine sectors (defined according to the ETDRS) treated with photocoagulation was measured. Amplitudes and implicit times were analysed in corresponding areas on the mfERG. Results: Mean mfERG amplitudes increased after photocoagulation (21.5 +/- 8.0 nV/deg(2) versus 16.8 +/- 6.1 nV/deg(2); p = 0.012), whereas no difference was seen in implicit times. Mean OCT values in the treated regions were lower at follow-up (272 +/- 23 mum versus 327 +/- 79 mum; p = 0.013). No correlation was seen between changes in mfERG response and changes in OCT values. The decrease in retinal thickness was correlated with the number of laser spots applied (p = 0.002). Conclusions: Focal argon laser treatment is effective in reducing retinal thickness. In addition, treated areas tend to show improved retinal function as demonstrated by increased amplitudes on mfERG.
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| 15. |
- Selvander, Madeleine, et al.
(författare)
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Cataract surgeons outperform medical students in Eyesi virtual reality cataract surgery: evidence for construct validity.
- 2013
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Ingår i: Acta Ophthalmologica. - : Wiley. - 1755-3768 .- 1755-375X. ; 91:5, s. 469-474
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Tidskriftsartikel (refereegranskat)abstract
- Purpose: To investigate construct validity for modules hydromaneuvers and phaco on the Eyesi surgical simulator. Methods: Seven cataract surgeons and 17 medical students performed capsulorhexis, hydromaneuvers, phaco, navigation, forceps, cracking and chopping modules in a standardized manner. Three trials were performed on each module (two on phaco) in the above order. Performance parameters as calculated by the simulator for each trial were saved. Video recordings of the second trial of the modules capsulorhexis, hydromaneuvers and phaco were evaluated with the modified Objective Structured Assessment of Surgical Skill (OSATS) and Objective Structured Assessment of Cataract Surgical Skill (OSACSS) tools. Results: Cataract surgeons outperformed medical students with regard to overall score on capsulorhexis (p < 0.001, p = 0.035, p = 0.010 for the tree iterations, respectively), navigation (p = 0.024, p = 0.307, p = 0.007), forceps (p = 0.017, p = 0.03, p = 0.028). Less obvious differences in overall score were found for modules cracking and chopping (p = 0.266, p = 0.022, p = 0.324) and phaco (p = 0.011, p = 0.081 for the two iterations, respectively). No differences in overall score were found on hydromaneuvers (p = 0.588, p = 0.503, p = 0.773), but surgeons received better scores from the evaluations of the modified OSATS (p = 0.001) and OSACSS (capsulorhexis, p = 0.003; hydromaneuvers, p = 0.017; phaco, p = 0.001). Conclusions: Construct validity was found on several modules previously not investigated (phaco, hydromaneuvers, cracking and chopping, navigation), and our results confirm previously demonstrated construct validity for capsulorhexis and forceps modules. Interestingly, validation of the hydromaneuvers module required OSACSS video evaluation tool. A further development of the scoring system in the simulator for the hydromaneuvers module would be advantageous and make training and evaluation of progress more accessible and immediate.
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| 16. |
- Selvander, Madeleine, et al.
(författare)
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Virtual reality cataract surgery training: learning curves and concurrent validity.
- 2012
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Ingår i: Acta Ophthalmologica. - : Wiley. - 1755-3768 .- 1755-375X. ; 90, s. 412-417
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Tidskriftsartikel (refereegranskat)abstract
- Purpose: To investigate initial learning curves on a virtual reality (VR) eye surgery simulator and whether achieved skills are transferable between tasks. Methods: Thirty-five medical students were randomized to complete ten iterations on either the VR Caspulorhexis module (group A) or the Cataract navigation training module (group B) and then two iterations on the other module. Learning curves were compared between groups. The second Capsulorhexis video was saved and evaluated with the performance rating tool Objective Structured Assessment of Cataract Surgical Skill (OSACSS). The students' stereoacuity was examined. Results: Both groups demonstrated significant improvements in performance over the 10 iterations: group A for all parameters analysed including score (p < 0.0001), time (p < 0.0001) and corneal damage (p = 0.0003), group B for time (p < 0.0001), corneal damage (p < 0.0001) but not for score (p = 0.752). Training on one module did not improve performance on the other. Capsulorhexis score correlated significantly with evaluation of the videos using the OSACSS performance rating tool. For stereoacuity < and ≥120 seconds of arc, sum of both modules' second iteration score was 73.5 and 41.0, respectively (p = 0.062). Conclusion: An initial rapid improvement in performance on a simulator with repeated practice was shown. For capsulorhexis, 10 iterations with only simulator feedback are not enough to reach a plateau for overall score. Skills transfer between modules was not found suggesting benefits from training on both modules. Stereoacuity may be of importance in the recruitment and training of new cataract surgeons. Additional studies are needed to investigate this further. Concurrent validity was found for Capsulorhexis module.
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| 17. |
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| 18. |
- Wittström, Elisabeth, et al.
(författare)
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Electrophysiological evaluation and visual outcome in patients with central retinal vein occlusion, primary open-angle glaucoma and neovascular glaucoma.
- 2010
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Ingår i: Acta Ophthalmologica. - : Wiley. - 1755-3768 .- 1755-375X. ; 88, s. 86-90
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Tidskriftsartikel (refereegranskat)abstract
- Purpose: To evaluate patients with central retinal vein occlusion (CRVO) and neovascular glaucoma (NVG) using electrophysiology in order to gain better understanding of visual outcome and risk factors, such as previously diagnosed primary open-angle glaucoma (POAG). Methods: Eighty-three patients (83 eyes) initially presenting with CRVO and examined with full-field electroretinography (ERG) within 3 months of the thrombotic event were analysed retrospectively regarding treatment, risk factors and visual outcome. In addition, 30 patients initially presenting with NVG caused by CRVO were also investigated regarding risk factors using electrophysiology in order to determine the cause of their visual impairment. Results: Nineteen (23%) of the 83 patients initially presenting with CRVO had been diagnosed previously with POAG. Ninety-five per cent (18/19) of all the patients with previously diagnosed glaucoma developed ischaemic CRVO. Thirty-four per cent of the patients initially presenting with CRVO (28/83) developed NVG. Sixty-eight per cent (13/19) of the patients with previous glaucoma developed NVG, compared to 23% (15/64) of the patients without previous POAG. In the patients who initially presented with NVG, full-field ERG demonstrated a remaining retinal function of both cones and rods, indicating that the main cause of visual impairment is ischaemia of the ganglion cell layer. Conclusion: Glaucoma is a significant risk factor for developing ischaemic CRVO and subsequent NVG. The presence of POAG in CRVO worsens visual outcome. NVG is associated with preserved photoreceptor function, thus indicating ischaemia of the ganglion cell layer as the primary cause of visual impairment. This emphasizes the importance of prompt treatment of ischaemia and elevated intraocular pressure in these patients.
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| 19. |
- Xu, Can, et al.
(författare)
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Transscleral visible/near-infrared spectroscopy for quantitative assessment of haemoglobin in experimental choroidal tumours.
- 2012
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Ingår i: Acta Ophthalmologica. - : Wiley. - 1755-3768 .- 1755-375X. ; 90, s. 350-356
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Tidskriftsartikel (refereegranskat)abstract
- Purpose: To study the feasibility of using transscleral visible/near-infrared spectroscopy (Vis/NIRS) to estimate the content of haemoglobin in choroidal tumour phantoms of ex vivo porcine eyes. Methods: Thirty enucleated porcine eyes were prepared with a tumour phantom made by injecting a suspension of gelatine, titanium dioxide and human blood into the suprachoroidal space. The blood concentrations used were 2.5%, 25% and 50%, with 10 eyes in each group. Alternating Vis/NIRS measurements were taken over the phantom inclusion and on the opposite (normal) side of each eye. For statistical analysis, a genetic algorithm was utilized to suppress insignificant wavelengths in the spectra. The processed spectra were then used to build a regression model based on partial least squares regression and evaluated by twofold cross-validation. Results: Ultrasonography revealed that all phantoms were localized within the suprachoroidal space with no penetration through the retina. The largest mean diameters of the phantoms with 2.5%, 25% and 50% blood were 15.5, 15.2 and 15.7 mm, respectively (p > 0.05). The largest mean thicknesses were 4.5, 4.5 and 4.8 mm, respectively (p > 0.05). Statistical analysis of the spectral data showed that it was possible to correctly discriminate between the normal side and the tumour phantom side of the eyes in 99.88% of cases. The phantoms could be correctly classified according to their blood concentrations in 99.42% of cases. Conclusions: This study demonstrates that transscleral Vis/NIRS is a feasible and accurate method for the detection of choroidal tumours and to assess the haemoglobin content in such lesions.
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| 20. |
- Åsman, Peter, et al.
(författare)
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Internet-based assessment of medical students' ophthalmoscopy skills
- 2010
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Ingår i: Acta Ophthalmologica Scandinavica. - : Wiley. - 1395-3907 .- 1600-0420 .- 1755-375X .- 1755-3768. ; 88:8, s. 854-857
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Tidskriftsartikel (refereegranskat)abstract
- Purpose: Ophthalmoscopy is an important skill in undergraduate medical education. The use and outcome of a novel Internet-based method for assessing motor skills-related aspects of ophthalmoscopy skills in medical students are described. Methods: A total of 139 students in Malmö and 255 students in Umeå were assessed during four consecutive semesters. An optic disc photograph was obtained in each student. At assessment each student was asked to examine the eye of a fellow student. Fifteen disc photographs were displayed on a computer screen. One of the photographs was from the fellow student. The remaining images had been randomly selected. The student was asked to identify the optic disc of the fellow student from the 15 photographs on the screen. In one semester, the time spent on this by each student was recorded. Results: All students completed the task. The average pass ratio was 96.4% (ranging from 94.0% to 98.0%). Median student times were 5.53 mins in Malmö and 6.36 mins in Umeå. Conclusions: This is the first automated, Internet-based assessment of an ophthalmic motor skill performed in co-operation between universities. The method used bears more similarities to real-life ophthalmoscopy than methods that use model eyes. Time investments and infrastructure demands were comparatively low. The method was designed for stand-alone assessment of ophthalmoscopy or as an objective structured clinical examination station, but it may also be used during the learning process. The collaboration between universities was easily transformed into routine practice and similar projects should be encouraged to increase the standardization of assessment
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| 21. |
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| 22. |
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| 23. |
- Edén, Ulla, et al.
(författare)
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Epidemiology of aniridia in Sweden and Norway.
- 2008
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Ingår i: Acta Ophthalmologica. - : Wiley. - 1755-3768 .- 1755-375X. ; 86, s. 727-729
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Tidskriftsartikel (refereegranskat)abstract
- Purpose: To investigate the epidemiology of aniridia in the populations of Sweden and Norway. Methods: A thorough search for aniridia patients has been performed in Sweden and Norway. All participants had a clinical ophthalmological examination documented through photography. Blood samples were taken for mutation analysis and pedigrees were established. Results: A total of 181 patients with aniridia were identified in the two countries. This gives an age-specific prevalence of 1:72 000 in the entire region, 1:70 000 in Sweden and 1:76 000 in Norway. A total of 124 individuals (69%) were examined. Male/female ratio was 0.94 (Sweden 0.85 and Norway 1.2). Mean age of the examined patients was 29 years and median age 25 years. We did not find any significant age difference between the two countries. The mean visual acuity (VA) was 0.19 (Sweden 0.19 and Norway 0.18).The number of families with more than one affected member was 31 and the number of sporadic cases was 40. Conclusion: We have done a thorough search of the literature, but we have found no earlier studies describing aniridia in an entire country and only a few reports from larger areas. We assume that most aniridia patients have been found and the aniridia prevalence of 1:72 000 can be regarded as well supported. Further studies on other aspects of aniridia are in progress, and information from these can contribute to guidelines for the care of patients with this rare but serious disease.
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| 24. |
- Ehinger, Berndt, et al.
(författare)
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Allvar Gullstrand (1862-1930) - the Gentleman with the Lamp.
- 2011
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Ingår i: Acta Ophthalmologica. - : Wiley. - 1755-3768 .- 1755-375X. ; 89, s. 701-708
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Tidskriftsartikel (refereegranskat)abstract
- This is a biography of Allvar Gullstrand (1862-1930) on the occasion of the centennial of his 1911 Nobel Prize in physiology or medicine. We reviewed pertinent literature and we did archival studies at the Uppsala University Library and the Regional State Archives at Lund as well as the Nobel Archives at the Royal Swedish Academy of Sciences in Stockholm. Allvar Gullstrand was a brilliant scientist with an exceptional personality. He gave mathematical descriptions of the dioptric system of the human eye with unprecedented accuracy, and he invented and designed ophthalmological instruments of far-reaching importance. The two most valuable ones are the slit lamp and the reflexless ophthalmoscope. Both are in everyday use by any ophthalmologist in the world. Allvar Gullstrand is so far the only ophthalmologist who has been given a Nobel Prize for work in ophthalmology, and he deserved it well.
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