Background:​ Fibrous dysplasia (FD) is a rare disorder of expansile fibro-osseous lesions that may be associated with extraskeletal features as part of McCune-Albright syndrome (MAS). Optic disc edema is a potentially serious ophthalmologic finding that has been rarely reported in patients with FD/MAS. The purpose of this study was to investigate the prevalence and potential clinical associations of optic disc edema in a large cohort.

Methods:​ Clinical records were reviewed from subjects in an ongoing FD/MAS natural history study. Computed Tomography scans were evaluated for the presence of structural craniofacial abnormalities associated with optic disc edema, including Chiari I malformation and space-occupying lesions. Craniomorphometric analyses were performed to determine optic canal diameter and intracranial volume. Statistical analyses were performed to compare clinical and radiographic features between subjects with and without optic disc edema.

Results:​ Optic disc edema was diagnosed in 7/187 subjects, for a prevalence of 3.7%. All subjects with optic disc edema were diagnosed before age 18 years and had mild, non-progressive disease. Radiographic structural abnormalities, including Chiari I malformation, aneurysmal bone cysts, and arachnoid cysts, were associated with higher odds of optic disc edema (odds ratio [OR] 24.3;​ 95% confidence interval [CI], 4.2 to 121.4;​ p < 0.01) (OR 18.0;​ 95% CI, 3.4 to 108.2;​ p < 0.01). Treatment with leuprolide, a gonadotropin releasing hormone analog, was also associated with optic disc edema (OR 26.0;​ 95% CI 3.3 to 177.5;​ p < 0.05). There was no significant association of optic disc edema with other MAS endocrinopathies, medications, optic canal diameter, or intracranial volume.

Conclusion:​ Optic disc edema is an uncommon but potentially serious complication of craniofacial FD, which may occur more frequently in pediatric patients and those with structural craniofacial abnormalities. The potential association of leuprolide therapy with optic disc edema in this population warrants further study.