1 IntroductionThyroid-associated ophthalmopathy (TAO) is an immune-mediated inflammatory disorder that affects the orbital tissues, commonly associated with Graves’ disease. The condition is characterized by symptoms such as eyelid retraction, exophthalmos, diplopia due to extraocular muscle involvement, and in severe cases, optic nerve compression leading to vision loss1. Treatment modalities for TAO include systemic corticosteroids, orbital radiotherapy and orbital decompression surgery2,3.Choroidal folds are a clinical sign observed as undulations in the retina and choroid, typically presented with blurred vision or metamorphopsia4. These folds can result from various conditions that cause sufficient compressive stress within the choroid, such as choroidal and orbital tumors and scleral buckling procedures4. Patients with TAO who exhibit choriordal folds often experience severe and chronic compression. However, this finding can also be observed during acute and severe exacerbations5,6. Treatment approaches for choroidal folds are primarily directed at the underlying cause, which may involve immunosuppressive therapy or surgical intervention7.The authors report a case of a 54-year-old male presenting with a one-year history of bilateral vision loss and choroidal folds, who was diagnosed with TAO previously. Subsequent examinations revealed bilateral cataracts and lens dislocation. Computed Tomography scan showed mild bilateral extraocular muscle thickening without orbital apex crowding. So the patient was advised to undergo cataract surgery at first, and his vision was restored. Two months following the procedure, the patient again exhibited blurred vision, along with severe restriction of eye movements in all directions in the right eye. Further assessment confirmed the diagnosis of dysthyroid optic neuropathy (DON), and the patient was subsequently treated with tocilizumab.