| 1. |
- Lennartsson, Finn, et al.
(author)
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Pre- and Postnatal Damage to the Retro-Geniculate Visual Pathways Cause Retinal Degeneration Predictive for Visual Function
- 2021
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In: Frontiers in Human Neuroscience. - : Frontiers Media SA. - 1662-5161. ; 15
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Journal article (peer-reviewed)abstract
- To increase the understanding of the relationship between structure and function in individuals with damage to the brain from different stages of maturation of the visual system, we examined 16 teenagers and young adults. We used diffusion-weighted magnetic resonance imaging (MRI) and fiber tractography of the optic radiation (OR) and optical coherence tomography (OCT) of the peripapillary retinal nerve fiber layer (pRNFL) and the ganglion cell layer + inner plexiform layer (GC+IPL) in the macula. Visual field (VF) function was assessed with the Humphrey Field Analyzer (HFA). Injuries to the immature OR were associated with thinning of the pRNFL and GC+IPL, and corresponding VF defects irrespectively of timing of the lesion. However, in cases with bilateral white-matter damage of immaturity (WMDI) we noticed a well preserved central VF despite a very thin GC+IPL. We speculate that this is due to plasticity in the immature visual system. Similar results were not noticed among cases with unilateral damage, acquired pre- or postnatally, in which the central VF was affected in most cases. OCT has proved to be a valuable targeted tool in children with damage to the retro-geniculate visual pathways, and that focal thinning of the GC+IPL predicts VF defects. This brief research report includes a review of four previously published papers. In addition, we present one new case and apply a recently developed classification system for CVI. The classification was applied on cases with bilateral WMDI to investigate its relation to retinal structure.
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| 2. |
- Nilsson, Maria, et al.
(author)
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Case report : Bilateral damage to the immature optic radiation and secondary massive loss of retinal ganglion cells causing tunnel vision
- 2023
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In: Frontiers in Neuroscience. - 1662-4548. ; 17
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Journal article (peer-reviewed)abstract
- We describe the case of a 30-year-old woman, who needed a formal report on her visual impairment to seek support from society. She was born preterm, and during her neonatal period, she suffered from bilateral intraventricular hemorrhage (IVH) grade 3, a condition that can cause cerebral visual impairment (CVI) due to damage to the retro-geniculate visual pathways. Individuals with such brain damage of this severity are often restricted by cerebral palsy (CP) and intellectual disability, and thus have a limited ability to cooperate in the assessment of visual function. However, our patient was capable of providing reliable test results, and she manifested only a small island of central vision in each eye, with additional reduced visual acuities. She cooperated well in examinations involving MRI of the brain, optical coherence tomography (OCT) of retinal ganglion cells, and multi-focal visual evoked potentials, with each test providing information about potential limitations in the structural prerequisites for visual function. What distinguishes our case is the severity of the damage to the optic radiations and the massive secondary loss of most of her retinal ganglion cells (GCs). However, there is some measurable visual function, which may be due to developmental neuroplasticity during early development, when surviving GCs prioritize the central visual field. Despite her visual difficulties, she is a keen portrait painter. Our patient may be representative of, and a spokesperson for, other individuals with extensive brain damage of the same etiology, who are unable to perform perimetric tests and therefore run the risk of not being recognized as severely visually impaired, and consequently, not being given the best conditions for habilitation. OCT may serve as a helpful diagnostic tool. Aim: This study aims to describe visual behavior and practical applications of visual function in relation to structural prerequisites for visual function.
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| 3. |
- Lin, An-Shen, et al.
(author)
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Novel flavonoids of Thelypteris torresiana
- 2007
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In: Chemical and Pharmaceutical Bulletin. - : Pharmaceutical Society of Japan. - 0009-2363 .- 1347-5223. ; 55:4, s. 635-637
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Journal article (peer-reviewed)abstract
- In our continuing research on cytotoxic components from the Formosan pteridophyte Thelypteris torresiana (GAUD.) ALSTONONE, two new compounds, a novel flavonoid, flavotorresin (1), and a flavonoid diglycoside, multi-florin C (2), along with five known compounds, were isolated. The structural elucidation was established on the basis of spectroscopic data analysis. The possible biosynthetic pathway of the flavonoids from this fern is summarized.
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| 4. |
- Öhnell, Hanna Maria, et al.
(author)
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Ageing and glaucoma progression of the retinal nerve fibre layer using spectral-domain optical coherence tomography analysis
- 2021
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In: Acta Ophthalmologica. - : Wiley. - 1755-375X .- 1755-3768. ; 99:3, s. 260-268
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Journal article (peer-reviewed)abstract
- Purpose: To compare the effects of ageing and glaucoma progression on the thickness of the circumpapillary retinal nerve fibre layer (cpRNFL) and to evaluate the performance of a set of optical coherence tomography (OCT) progression analyses. Methods: The cpRNFL was measured twice by OCT at each of two visits made 10 years apart in 69 healthy individuals and 49 glaucoma patients. Both visits also included Humphrey 24-2 SITA standard testing. The change in cpRNFL thickness was analysed by linear regression, and a sub-analysis was performed on glaucoma patients with a perimetric mean deviation better than −10 dB at the first visit. The proportion of individuals whose OCT progression analyses indicated progression was also evaluated for the same groups. Results: The average cpRNFL thickness deteriorated by a mean of −0.16 μm/year in the healthy cohort, increased by 0.03 μm/year in the glaucoma cohort, and deteriorated by −0.24 μm/year in eyes with less severe glaucoma; there were no statistically significant differences between the groups. For 17 (30%) of 56 healthy individuals, at least one of the three different OCT progression analyses incorrectly indicated progression. Conclusions: No significant differences in change of cpRNFL thickness between visits were found when comparing healthy subjects with glaucoma patients. Also, further cpRNFL thinning was not observed in glaucomatous eyes in which at least one-third of the visual field had been lost. The OCT progression analyses generated a relatively high proportion of false positives. Using OCT for glaucoma follow-up may not be entirely straightforward.
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| 5. |
- Öhnell, Hanna Maria, et al.
(author)
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Detection of glaucoma progression by perimetry and optic disc photography at different stages of the disease : Results from the Early Manifest Glaucoma Trial
- 2017
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In: Acta Ophthalmologica. - : Wiley. - 1755-375X. ; 95:3, s. 281-287
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Journal article (peer-reviewed)abstract
- Purpose: To compare the earliest detection of progression in visual fields and monoscopic optic disc photographs at different stages of manifest glaucoma. Methods: This study evaluated 306 eyes in 249 patients with manifest open-angle glaucoma included in the Early Manifest Glaucoma Trial (EMGT). All patients in the trial were followed up regularly by standard automated perimetry and monoscopic optic disc photography, and the median follow-up time was 8 years. Progression was assessed in series of optic disc photographs and in series of visual fields using glaucoma change probability maps and the predefined EMGT progression criterion. The proportion of progressions detected first in visual fields and the proportion detected first in optic disc photographs were compared at different stages of glaucoma severity defined by the perimetric mean deviation (MD) of the baseline visual field. Results: Assessment of 210 eyes with early visual field loss, 83 eyes with moderate field loss, and 13 eyes with advanced field loss showed that, among the eyes exhibiting progression, the progression was detected first in the visual field in 80%, 79% and 100%, respectively. The predominance of visual field progressions at all stages was still apparent when using narrower (3-dB) MD intervals for staging. Conclusion: In the EMGT material on eyes with manifest open-angle glaucoma, the initial progression was detected much more often in the visual field series than in the optic disc photographs at all stages of disease.
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| 6. |
- Öhnell, Hanna Maria, et al.
(author)
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Dexamethasone eye-drops for treatment of retinopathy of prematurity
- 2022
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In: Ophthalmology Retina. - : Elsevier BV. - 2468-6530. ; 6:2, s. 181-182
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Journal article (peer-reviewed)abstract
- Both studies on animals and humans have demonstrated the role of inflammatory mediators on the retinopathy process.2,3 Dexamethasone is a glucocorticoid with a known reductive effect on several of these mediators and on the expression of VEGF.4Starting in 2016, infants receiving laser ablation for type 1 ROP at Skåne University Hospital were administered dexamethasone eye-drops postoperatively, usually three times daily. None of the infants receiving postoperative topical steroids needed retreatment, in comparison to a general retreatment frequency of 26% nationally when postoperative dexamethasone wasn’t administered routinely.5 During 2018 and 2019, two premature infants started the dexamethasone regimen before the planned laser treatment could be performed and in one the laser could be postponed, in the other the laser treatment was cancelled. Successively, several other infants with type 2 ROP that were considered at very high risk of requiring laser ablation were administered dexamethasone drops preoperatively and the regression of ROP changes were observed on multiple occasions. Consequently, for infants with type 2 ROP born in 2020, all were administered dexamethasone drops before the laser treatment, but usually in a lower dosage of one drop daily.We therefore aim to compare the treatment frequency for screened infants in the southern healthcare region of Sweden born during 2016 through 2020 to make a systematic retrospective analysis to compare dexamethasone treated and untreated infants.The retrospective study was carried through in accordance with the declaration of Helsinki and received ethical approval from the Swedish ethical board. The study followed the Strengthening and Reporting of Observational Studies in Epidemiology (STROBE) reporting guideline for cohort studies.
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| 7. |
- Öhnell, Hanna Maria, et al.
(author)
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Making a Correct Diagnosis of Glaucoma : Data from the EMGT
- 2019
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In: Journal of Glaucoma. - 1057-0829. ; , s. 859-864
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Journal article (peer-reviewed)abstract
- Précis: A correct diagnosis of glaucoma established at initial visits. Purpose: It has been suggested that a diagnosis of glaucoma cannot be certain until progression has been demonstrated. Our aim was to evaluate the correctness of a glaucoma diagnosis established after 2 initial visits. Patients and Methods: Patients included in the Early Manifest Glaucoma Trial (EMGT) who had continued follow-up for at least 15 years were included in this analysis. The patients had been recruited primarily through a population screening and were diagnosed with glaucoma if the Glaucoma Hemifield Test was outside normal limits in the same sector at two consecutive visits. A Glaucoma Hemifield Test classification of borderline was also diagnostic if corresponding optic disc findings were present. At least one of the following criteria had to be fulfilled during follow-up to confirm the initial diagnosis: (1) visual field progression in at least one eye according to the EMGT criterion; (2) development of manifest glaucoma in an initially ineligible fellow eye; (3) optic disc progression in at least one eye; (4) optic disc hemorrhages in at least 1 eye. Results: Of the 255 patients included in the EMGT, 117 were followed for at least 15 years, representing 147 eyes eligible for our study. During follow-up, 134 eyes (91%) showed visual field progression, and, of the remaining 13 eyes, only 4 (3%) did not fulfill any of the criteria to confirm the diagnosis. Conclusions: A diagnosis made applying strict criteria to 2 initial visual field tests, supported by optic disc findings if visual field findings were borderline, was almost always correct.
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| 8. |
- Öhnell, Hanna Maria, et al.
(author)
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Ophthalmic manifestations in children with tuberous sclerosis complex
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In: Acta Ophthalmologica. - 1755-375X.
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Journal article (peer-reviewed)abstract
- Purpose: To report on the ophthalmic findings in children with tuberous sclerosis complex (TSC) in southern Sweden, and to investigate the frequency of refractive errors, strabismus and cerebral visual impairment associated with this condition. Methods: This was a retrospective cohort study including all paediatric patients with TSC in southern Sweden born between 1983 and 2020. Medical records were reviewed regarding retinal findings, visual acuity, refractive error, strabismus, full-field electroretinography results and cerebral visual impairment. Results: Ophthalmological records were available for 50 of the 52 children in the region diagnosed with TSC. The mean age at the last visit was 12.4 (SD 7.2) years. Monocular visual acuity had been measured in 38 patients, and the median value did not deviate from that expected for their age in the better eye, but by −0.2 Snellen decimal acuity in the worse eye. Refractive errors were found in 62% of the patients, and strabismus in 16%. Retinal astrocytic hamartomas were found in 34% and achromatic patches in 34%. Ten of the patients on medication with vigabatrin were examined with full-field electroretinography and treatment had to be stopped or lowered in three (30%), due to a reduced response. Investigation of cerebral visual impairment had not been conducted in any of the children. Conclusion: Refractive errors and strabismus were common among children with TSC. None of the patients in this cohort had undergone investigation for cerebral visual impairment. The general awareness of cerebral visual impairment among ophthalmologists is poor and constitutes an important area for improvement.
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| 9. |
- Öhnell, Hanna Maria
(author)
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Progression in Glaucoma
- 2020
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Doctoral thesis (other academic/artistic)abstract
- The treatment of glaucoma is focused on reducing the intraocular pressure to a level at which progression is impeded. A diagnosis of glaucoma is not considered certain until progression is confirmed, and thus detecting progression is a central aspect in both the diagnosing and the monitoring of glaucoma patients. Progression can be identified either through examination of either functional changes in the visual field or structural changes in the retinal nerve fibre layer in the optic disc or in the retina. Optic disc photography, and optical coherence tomography (OCT) that uses laser light, are two methods that are widely used to detect structural changes.The objectives of the present research were three-fold: (1) to assess how often a correct diagnosis was made during the few initial clinical visits, when no knowledge of progression was available; (2) to compare visual field examination and optic disc photography as methods to detect progression in glaucoma patients; (3) to evaluate the capacity of OCT to detect the rate of change in the retinal nerve fibre layer. For the first and second objectives, we studied glaucoma patients that had been included in the Early Manifest Glaucoma Trial, in which up to 20 years of regular prospective examinations were performed. To achieve the third objective, two different cohorts of healthy individuals and glaucoma patients were re-examined at a 10-year follow-up visit.Automated visual field examinations with strict criteria for defining glaucoma resulted in a correct diagnosis in 97% of patients after only two initial visits. Comparing visual fields and optic disc photographs among the glaucoma patients, the visual field examinations detected progression approximately four times as often. However, in eyes without glaucoma, progression was detected equally often by the two methods. The OCT method could not demonstrate a statistically significant difference in rate of change between healthy individuals and glaucoma patients. The automated OCT progression analysis, which is designed to assist the clinician in detecting glaucoma progression, gave excessively high rates of false positives.Guidelines recommend examinations of both functional and structural measures throughout the lifelong follow-up of glaucoma, a goal that is seldom achieved in reality. Inasmuch as health care resources are limited, the results presented in this thesis can aid in selecting the optimal method to monitor this large group of patients with different stages of glaucoma.
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| 10. |
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