Abstract
Purpose: :
Vigabatrin is still prescribed for the treatment of West syndrome and refractory epilepsy despite visual loss reported in a third of treated patients. Visual loss can be demonstrated by visual field assessment and electroretinogram measurements. Our objective was to determine if retinal damages observed in the retina of vigabatrin-treated animals can be detected by in vivo imaging easier to achieve in infants.
Methods: :
The eye fundus of living vigabatrin-treated rats was examined at different periods of the treatment with a scanninglaser ophthalmoscope normally used in clinical studies.
Results: :
Eye fundus examination indicated that the disorganisation of the photoreceptor layer can be detected under either green or red illuminations. These retinal damages were more prominent in the dorsal retina as confirmed on histological sections. When the in vivo retina was examined under blue stimulation, autofluorescent spots were detected in a deep retina layer. Histological sections showed large fluorescent materials in the retinal pigment epithelium. Finally, whenindocyanine green was intravenously injected, no difference in choroids vascularization could be detected. However, the dye was observed to produce a honey comb pattern highlyreminiscent of the retinal pigment mosaic in vigabatrin-treated animals.
Conclusions: :
These in vivo observations indicate that vigabatrin-elicited retinal damages can be detected in theleaving animals by techniques classically used in clinical ophthalmology. Therefore, they suggest that in vivo imaging could be used to detect and follow the progression of retinaldamages in epileptic patients provided these damages have similar features in humans and animals.
Keywords: drug toxicity/drug effects • imaging methods (CT, FA, ICG, MRI, OCT, RTA, SLO, ultrasound) • retina