When Postoperative Inflammation Isn’t Benign: Thyroid Eye Disease Following Cataract Surgery

Thyroid eye disease (TED) is an autoimmune inflammatory disorder of the orbital tissues, most commonly associated with Graves' hyperthyroidism. Although it typically occurs in the presence of thyroid dysfunction, TED may also arise in euthyroid or subclinical states. Its onset after ocular surgery is uncommon and may mimic routine postoperative inflammation, delaying diagnosis. A 67-year-old Chinese-Malaysian man developed eyelid swelling, redness, and blurred vision two weeks after uncomplicated left-eye cataract surgery. He was initially treated for common postoperative complications, but his condition progressively worsened, with visual acuity declining from 6/12 (6/9 with pinhole preoperatively) to 6/30 without pinhole improvement over six months, accompanied by proptosis, diplopia, and optic nerve dysfunction. Laboratory tests revealed subclinical hyperthyroidism, and orbital contrast-enhanced computed tomography confirmed tendon-sparing enlargement of all extraocular muscles, consistent with sight-threatening TED. He received intravenous methylprednisolone, mycophenolate mofetil, and carbimazole, followed by urgent medial wall decompression due to worsening optic neuropathy, with subsequent visual improvement. TED following cataract surgery is rare but underscores the importance of considering atypical postoperative courses. Early recognition and adherence to guideline-based management are crucial to preserve vision.