A

Sudden, painless visual decline occurring months after cataract extraction is classically due to pseudophakic cystoid macular edema (Irvine-Gass syndrome), the most common cause of vision loss after cataract surgery [Radeck 2020, PMID 32468102]. Hydroxychloroquine/chloroquine toxicity produces a slowly progressive “bull’s-eye” maculopathy rather than an abrupt loss, and macular holes or chronic choroiditis are not specifically linked to recent cataract surgery.