Fibrous dysplasia: A rare cause of optic neuropathy.

Fibrous dysplasia (FD) is a progressive and benign osteodystrophic disease where cranial bones are most commonly affected. In this case report, we present a 27-year-old patient with previous diagnosis of FD who was referred to our clinic with sudden loss of visual acuity and color discrimination. Examination of the right eye was normal, whereas visual acuity on the left eye was 6/9 and color vision (CV) with Ishihara test plates was 9/12. The visual field (VF) demonstrated a peripheral concentric defect on the left eye. As visual acuity in the left eye decreased to 6/30 and computed tomography imaging of the brain and orbit showed optic nerve compression by immature bony structures, optic nerve decompression was recommended with the diagnosis of compressive optic neuropathy. Endoscopic transnasal orbital and optic canal decompression was performed. At the postoperative course, visual acuity on the left eye turned to 6/6, CV was 12/12, and VF improved markedly. In subjects with craniofacial FD, a multidisciplinary approach is important. If there is evidence of compressive optic neuropathy, surgery should be performed.