Characteristics of a unique visual field defect attributed to vigabatrin

Area of Science:

• Neuro-ophthalmology
• Epileptology
• Pharmacovigilance

Background:

• Vigabatrin (VGB) therapy is linked to peripheral vision impairment.
• Understanding the characteristics and risk factors of VGB-attributed visual field loss (V-AVFL) is crucial for patient management.

Purpose of the Study:

• To evaluate the characteristics and prevalence of VGB-attributed visual field loss (V-AVFL) in epilepsy patients.
• To identify associated risk factors for V-AVFL.

Main Methods:

• Analysis of visual fields and case notes from 88 patients with suspected V-AVFL.
• Inclusion of 42 patients on alternative antiepileptic drugs (AEDs) as a reference cohort.
• Utilized spontaneous reports and an open-label extension trial for case identification.

Main Results:

• 42 confirmed cases of V-AVFL were identified, predominantly bilateral and nasally profound.
• The prevalence of V-AVFL was 29%, with male gender showing a 2.1-fold increased relative risk.
• Age, weight, epilepsy duration, VGB dose, and concomitant AEDs did not predict V-AVFL occurrence.

Conclusions:

• VGB-attributed visual field defect is characterized by significant frequency, location, and severity.
• The typically asymptomatic nature of V-AVFL necessitates routine visual field examination for early detection.
• V-AVFL represents a unique and profound visual field defect associated with Vigabatrin therapy.