Characterization of vigabatrin-associated optic atrophy.
OBJECTIVE
To report the discovery of a previously unknown form of optic atrophy associated with use of the anti-epileptic drug vigabatrin.


METHODS
We conducted a retrospective analysis of digitally enhanced ocular fundus photographs, kinetic visual field maps and treatment parameters for 25 patients, who were selected to represent a large spectrum of visual field defects.


RESULTS
In all, 21 patients (84%) evidenced subtle, diffuse atrophy of the retinal nerve fibre layer, in a pattern accessible to scoring. Atrophy scores correlated with visual field remains and cumulative vigabatrin doses. A pathophysiological model is proposed that involves the lengths of intraocular (unmyelinated) retinal ganglion cell axons.


CONCLUSIONS
Optic atrophy attests to the irreversible nature of vigabatrin's visual toxicity. Ocular fundus imaging should prove useful for objectively monitoring vigabatrin-treated subjects for visual toxicity.
D000927:Anticonvulsants / Q000008:administration & dosage / Q000009:adverse effects*; D004305:Dose-Response Relationship, Drug; D005654:Fundus Oculi; D006801:Humans; D007091:Image Processing, Computer-Assisted; D009412:Nerve Fibers / Q000473:pathology; D009896:Optic Atrophy / Q000139:chemically induced* / Q000473:pathology / Q000503:physiopathology; D012165:Retinal Ganglion Cells / Q000473:pathology; D012171:Retinal Vessels / Q000473:pathology; D012189:Retrospective Studies; D020888:Vigabatrin / Q000008:administration & dosage / Q000009:adverse effects*; D014794:Visual Fields
D000927:Anticonvulsants; D020888:Vigabatrin