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- Gränse, Lotta, et al.
(författare)
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Electrophysiologic findings in two young patients with Bothnia dystrophy and a mutation in the RLBP1 gene
- 2001
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Ingår i: Ophthalmic Genetics. - : Swets & Zeitlinger Publishers. - 1744-5094 .- 1381-6810. ; 22:2, s. 97-105
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Tidskriftsartikel (refereegranskat)abstract
- Purpose: To characterize the clinical phenotype, with emphasis on electrophysiology, of two children with suspected Bothnia dystrophy. Methods: Two unrelated affected patients, 10 and 11 years old, were studied. Ophthalmological examination included testing of visual acuity, fundus inspection and fundus photography, kinetic perimetry, full-field electroretinogram (ERG), and multifocal ERG. The presence of a mutation in exon 7 of the RLBP1 gene was investigated by DNA sequencing. Results: Both patients were homozygous for the Arg234Trp-causing mutation in the RLBP1 gene, but the resulting disease phenotype appeared to vary somewhat between them. Visual acuity was moderately reduced in one patient and normal in the other. Fundus inspection at this age revealed no pathology in either patient and there were no signs of retinitis punctata albescens, which has been described previously as a frequent clinical feature of Bothnia dystrophy. The result of kinetic perimetry was normal. The final rod threshold was moderately elevated. Full-field ERG demonstrated the uncommon combination of absent rod response and normal cone response after 40 minutes of dark adaptation. However, after prolonged dark adaptation (20-24 h), both the rod response and the dark adaptation threshold became normal. Multifocal ERG was performed in one of the patients (the one with normal visual acuity and normal fundus appearance) and showed a reduced cone response in the central region of the tested area. There was no improvement of the multifocal ERG result after 20-24 h of dark adaptation. Conclusion: Patients with mutations in the RLBP1 gene (Arg234Trp) may have a normal fundus appearance early in the disease course. Multifocal ERG can be used for the objective documentation of the disturbed macular function, especially when the patient's visual acuity and fundus appearance are normal. The rod response is absent in the electroretinogram; however, after prolonged dark adaptation (20-24 hours), the rods recover completely. The central cones do not seem to recover.
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| 2. |
- Gränse, Lotta, et al.
(författare)
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Electrophysiology and ocular blood flow in a family with dominant optic nerve atrophy and a mutation in the OPA1 gene
- 2003
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Ingår i: Ophthalmic Genetics. - : Swets & Zeitlinger Publishers. - 1744-5094 .- 1381-6810. ; 24:4, s. 233-245
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE: To characterize the clinical phenotype, with emphasis on electrophysiology and blood flow measurements, of a family with dominant optic nerve atrophy and an identified mutation in the OPA1 gene. METHODS: Seven family members were examined. Ophthalmological evaluation included testing of visual acuity, ophthalmolscopy, kinetic perimetry, color vision testing, full-field electroretinography (ERG), multifocal electroretinography (MERG), and multifocal visual evoked potential (MVEP). Retrobulbar arterial blood flow and retinal capillary perfusion was measured in three patients using scanning laser Doppler flowmetry (SLDF) and color Doppler imaging techniques. PCR-SSCP and DNA sequencing determined the presence of a mutation in exon 18 of the OPA1 gene. RESULTS: The clinical characteristics varied considerably in the family. The ERG and the MERG demonstrated normal retinal function, while the MVEP was abnormal in all examined patients. Retinal and optic nerve head capillary perfusion was significantly decreased in the three patients examined with SLDF. Retrobulbar blood flow velocities were significantly decreased in the central retinal and ophthalmic arteries. In all seven examined subjects, a microdeletion (1756-1767del(12 bp)) in the OPA1 gene was identified. CONCLUSION: Patients with a mutation in the OPA1 gene have a very variable phenotype. MVEP and blood flow measurements are two new objective methods for an easier detection of this specific genetic optic nerve atrophy.
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| 6. |
- Ponjavic, Vesna, et al.
(författare)
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Alterations in electroretinograms and retinal morphology in rabbits treated with vigabatrin
- 2004
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Ingår i: Documenta Ophthalmologica. - 1573-2622. ; 108:2, s. 125-133
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Tidskriftsartikel (refereegranskat)abstract
- PURPOSE: To determine whether long-term treatment with the anti-epileptic drug vigabatrin causes damage to rabbit retina.METHODS: Five rabbits were treated continuously with a daily dose of vigabatrin solution per orally during a period of 1-8 months. Two rabbits receiving water were used as controls. Repeated full-field electroretinograms (every two weeks) were assessed during this period. Vigabatrin serum concentration was repeatedly measured for securing successful drug administration. After termination of treatment the rabbits were sacrificed and the morphology of the sectioned retina was studied.RESULTS: In all rabbits treated with vigabatrin the serum analyses repeatedly demonstrated elevated drug concentration. Full-field electroretinograms demonstrated normal rod function in all treated rabbits, but reduced cone function in two of the five treated rabbits verified by 30Hz flicker stimulation. Morphologic studies of the sectioned retina demonstrated GFAP immunoactivity of the glial cells localized in the retinal periphery in all five treated rabbits, one of which had staining also in the centrally localized glial cells. The treated rabbits also demonstrated a weaker GAD staining in the IPL and less positive amacrine cells, compared to the controls. Only two treated rabbits had normal GABA staining while three had an enhanced GABA immunoreactivity and undistinguishable fibers in the IPL. In three out of five treated rabbits the Müller cells were short, stubby and fragmented, with swollen endfeet.CONCLUSION: This study demonstrates changes in histopathology caused by vigabatrin in an animal model, which has not been reported previously. We have found that vigabatrin orally administrated to rabbits does not affect rod function but may reduce cone function in the full-field electroretinogram, which is similar to the previously reported vigabatrin effect on the human ERG. The results indicate that vigabatrin may damage or influence, at least one cell type in the rabbit retina.
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| 7. |
- Ponjavic, Vesna, et al.
(författare)
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Reduced full-field electroretinogram (ERG) in a patient treated with methotrexate.
- 2004
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Ingår i: Acta Ophthalmologica Scandinavica. - : Wiley. - 1395-3907 .- 1600-0420. ; 82:1, s. 96-99
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Tidskriftsartikel (refereegranskat)abstract
- Purpose: To examine retinal function in a patient with decreased vision possibly due to treatment with methotrexate. Methods: Ophthalmological examination included testing of visual acuity (VA), fundus inspection, fundus photography and kinetic perimetry. Retinal function was tested objectively with three electrophysiological methods: full-field electroretinography (ERG), multifocal electroretinography (mfERG) and electro-oculography (EOG). Results: A 13-year-old boy with psoriasis arthritis had been treated with methotrexate on a weekly basis for 8.5 years. After terminating treatment, his VA, which was reduced to 0.3 in both eyes initially, improved during the following 3 years but did not return to normal. No visual field defects were found with kinetic perimetry. The rod and cone responses in the full-field ERG were markedly reduced in b-wave amplitude initially, but grew slowly to nearly normal values 3 years later. After withdrawal of the drug, the mfERG demonstrated normal responses in the macular region. The Arden index in the EOG was normal. Conclusion: Chronic treatment with methotrexate may affect VA, and may reversibly reduce rod and cone function. In patients who use systemic medication and whose vision is reduced, objective evaluation of retinal function with electrophysiological methods is recommended.
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| 8. |
- Ponjavic, Vesna, et al.
(författare)
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Retinal dysfunction and anterior segment deposits in a patient treated with rifabutin
- 2002
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Ingår i: Acta Ophthalmologica Scandinavica. - : Wiley. - 1395-3907. ; 80:5, s. 553-556
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Tidskriftsartikel (refereegranskat)abstract
- Purpose: To describe the clinical and electrophysiological findings in a young boy with decreased vision possibly due to retinal damage by rifabutin. Methods: An 8-year-old boy with osteomyelitis was referred due to visual disturbance. During a period of 4 years, the boy was examined six times with electroretinography. Ophthalmological examination included testing of visual acuity, slit-lamp inspection, fundus inspection, fundus photography and kinetic perimetry. Two electrophysiological methods were performed for objective evaluation of retinal function, namely full-field electroretinography and multifocal electroretinography. Results: We found a slightly reduced visual acuity, a slowly increasing amount of yellow-white deposits on the posterior surface of the cornea and on the anterior part of the lens, a normal fundus appearance, and normal visual fields. However, the electroretinogram was abnormal on several occasions during therapy with rifabutin, but returned to normal 3 months after withdrawal of the medication. The multifocal electroretinogram returned to normal after the full-field electroretinogram had done so. The anterior chamber deposits still remain. Conclusion: Long-term treatment with rifabutin may have a reversible and previously undescribed side-effect on retinal function. The drug may also accumulate irreversibly on the posterior surface of the cornea and on the anterior surface of the lens. We suggest that objective evaluation of retinal function with electrophysiological methods should be performed in patients with visual disturbance during treatment with rifabutin.
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