Ocular adverse events associated with endocrine-based breast cancer therapies: a 20-year global faers disproportionality analysis

Objective/Purpose : To evaluate ocular adverse event (AE) reporting signals associated with endocrine-based breast cancer therapies, including selective estrogen receptor modulators, aromatase inhibitors, and selective estrogen receptor degraders, using a large-scale global pharmacovigilance database. Design : Retrospective pharmacovigilance disproportionality analysis. Subjects, Participants, and/or Controls : Adverse event reports from the U.S. Food and Drug Administration Adverse Event Reporting System (FAERS), January 2004–September 2024. Methods, Intervention, or Testing : Reports were deduplicated and standardized using validated methods. Ocular AEs were identified using MedDRA Preferred Terms and categorized by anatomical involvement. Disproportionality analysis was performed using reporting odds ratios (RORs) with 95% confidence intervals (CIs), applying Evans criteria (ROR >2, χ² >4, n ≥3) and a Bayesian information component criterion (IC025 >0) to identify disproportionality signals. Results : Distinct patterns of ocular AE reporting were observed across endocrine therapies. Tamoxifen showed the broadest and strongest reporting signals, particularly involving the posterior segment and optic nerve, including macular hole (ROR=81.68), maculopathy (64.23), retinopathy (58.26), vitreous detachment (44.24), and optic neuropathy (33.73). Anastrozole showed a distinctive signal for vitreoretinal traction syndrome (ROR=382.55, based on 15 reports), along with cystoid macular edema, papilledema, and optic atrophy. Conclusions : Endocrine-based breast cancer therapies are associated with distinct and clinically notable ocular AE reporting signals, most prominently for tamoxifen and anastrozole, involving the posterior segment and optic nerve. As disproportionality analysis identifies reporting signals rather than incidence, comparative risk, or causality, these hypothesis-generating findings support increased ophthalmic vigilance and further study rather than definitive monitoring recommendations.