Paradoxical Acute Angle Closure Following Topiramate Discontinuation: A Case Report

Background: Topiramate is a widely prescribed antiepileptic medication increasingly used for off-label indications such as migraine prevention, weight loss, and mood stabilization. While topiramate-induced acute angle closure (AAC) is rare, it has become more frequently recognized due to its expanding use. This condition is typically associated with ciliochoroidal effusion and anterior displacement of the lens-iris diaphragm. Although most cases occur shortly after therapy initiation, emerging reports suggest angle compromise may also occur after abrupt drug discontinuation. Methods: We describe 2 cases of bilateral AAC in female patients without prior history of glaucoma. Case 1 presented 2 days after discontinuing topiramate, while Case 2 developed symptoms during active treatment. Both cases were evaluated with slit lamp examination, gonioscopy, tonometry, optical coherence tomography (OCT), and ultra-widefield fundus imaging. Results: Case 1 showed shallow anterior chambers, optic disc cupping, and normal intraocular pressure (IOP) despite recent drug withdrawal. Case 2 demonstrated acute vision loss, significant myopic shift (>5.00 D), and IOP elevation up to 40 mmHg. Anterior segment OCT revealed quadrant-specific angle narrowing. Both patients improved with discontinuation of topiramate and appropriate medical therapy, including aqueous suppressants and cycloplegics. Anatomical normalization and refractive recovery were documented over follow-up. Conclusion: These cases broaden the known spectrum of topiramate-induced angle closure by highlighting both paradoxical post-discontinuation and classic acute presentations. Clinicians should maintain a high index of suspicion for AAC in patients with recent or current topiramate exposure, regardless of IOP. Early recognition and ophthalmology referral are essential to prevent permanent vision loss.