Post-radioiodine De Novo Onset Graves' Ophthalmopathy: Case Reports and a Review of the Literature

New-onset Graves' ophthalmopathy (GO) following radioiodine treatment (RAI) and worsening of existing GO are well-described in the endocrinology literature. These phenomena are recognized by ophthalmologists, yet poorly documented in the ophthalmology literature. Two male patients, aged 43 and 62 years, respectively, with Graves' disease without GO, received RAI. Four months later, one patient developed acute GO with unilateral reduction in visual acuity, conjunctival chemosis, lagophthalmos, bilateral severely restricted ocular motility, and lid retraction. High-dose intravenous steroids, followed by oral steroids, led to a dramatic clinical improvement. The second patient received a second dose of RAI for persistent hyperthyroidism and subsequently developed acute GO-comprising restricted ocular motility, peri-orbital swelling, and conjunctival chemosis. Symptoms gradually resolved on continued carbimazole treatment. Neither patient received pre-RAI prophylactic glucocorticoids, as currently they are only recommended for patients with pre-existing GO or multiple risk factors. We discuss the limitations of using this risk-based approach in preventing new-onset GO following RAI therapy.