Vigabatrin Safety and Vision Reporting: A FAERS and EudraVigilance Analysis

Vigabatrin is an antiepileptic medication used to treat infantile spasms and refractory focal seizures. However, its clinical use is limited by ophthalmic safety concerns, particularly concentric peripheral visual field loss, which occurs in approximately 30-40% of adults receiving long-term vigabatrin therapy. Consequently, upon the FDA's approval of vigabatrin in 2009, a Risk Evaluation and Mitigation Strategy (REMS) was implemented, requiring patient enrollment, prescribers and dispensing pharmacies certification, and regular vision monitoring. In July 2016, the Vigabatrin REMS program was revised to remove the patient registry, pharmacy tracking, and mandatory vision testing, thereby reducing administrative burdens. The FDA Adverse Event Reporting System (FAERS) is a publicly available U.S. database that tracks adverse event reports, while EudraVigilance serves the same function for the European Union. The primary objective of this study was to evaluate whether the 2016 revisions to the vigabatrin safety program were associated with changes in the reporting frequency of ophthalmic and visual-related adverse events using FAERS. The second objective was to compare the FAERS and EudraVigilance databases to evaluate ocular and vision-related adverse events associated with vigabatrin over the same study period. Vigabatrin-associated ophthalmic or vision-related adverse event reports submitted to FAERS and EudraVigilance between January 2010 and December 2025 were extracted. Demographic variables (age, sex), clinical indication, reporter type, report dates, and specific adverse events were included. Duplicate reports were excluded. Annual reporting proportions were calculated, and reporting patterns were compared before and after the July 2016 REMS revision using the Mann-Whitney U test and chi-square analysis. Of the 1032 vigabatrin-associated cases, 591 occurred during the pre-revision period, and 441 during the post-revision period. The median age of patients was 7 years (IQR 1.8,29.0) in the pre-revision group and 5 years (IQR 1.3,24.3) in the post-revision group (p = 0.193). Sex distribution was comparable between groups (p = 0.499). Healthcare providers submitted more reports than consumers in both the pre-revision group (84.4% vs. 15.6%) and post-revision group (67.9% vs. 32.1%) (p < 0.001). Indications for vigabatrin use included infantile spasms (19.3% vs. 21.5%), seizures (17.9% vs 30.4%), unknown indication (33.8% vs 14.3%), multiple indications (27.2% vs. 28.8%), and other indications (1.69% vs. 4.99%) in the pre-revision and post-revision groups (p < 0.001), respectively. In FAERS, visual impairment, particularly visual field defects, was the most frequently reported adverse event in both pre- and post-revision periods (n = 255 vs. n = 174; p < 0.001). Significant decreases were also observed in reports of retinal abnormalities (n = 79 vs. n = 51; p = 0.014) and optic nerve abnormalities (n = 54 vs. n = 27; p = 0.003). Other ocular and vision adverse event categories did not differ significantly between periods. The annual proportion of vigabatrin ophthalmic or vision-related adverse event reports differed between the two pharmacovigilance databases over time. EudraVigilance consistently reported a higher proportion of adverse reactions than FAERS, with notable peaks in 2016 (34.7%) and 2019 (28.8%). In contrast, FAERS demonstrated a relatively stable downward trend, declining from 13.8% in 2010 to 4.4% in 2025. The 2016 revision of the Vigabatrin REMS program was associated with a decline in reported ophthalmic and visual-related adverse events in FAERS. However, because FAERS and EudraVigilance are spontaneous reporting systems, these findings likely represent changes in reporting patterns rather than the actual incidence of vigabatrin-associated ocular and visual adverse events. Differences between FAERS and EudraVigilance highlight the influence of regional pharmacovigilance practices and emphasize the importance of continued post-marketing surveillance to monitor the ocular safety of vigabatrin.