Determinants of Non-infectious Scleritis Complications and Their Impact on Visual Outcome: Results from the International AIDA Network Scleritis Registry

Introduction: Scleritis is a rare and severe ocular inflammatory disease that is often associated with potentially sight-threatening ocular complications. The aim of the present study was to characterize ocular complications in non-infectious scleritis and identify predictive variables for their development. Methods: Data for this registry-based study were extracted from the AutoInflammatory Disease Alliance Network for Scleritis Registry. Univariate analysis was performed to examine potential associations of demographic and clinical variables with the development of ocular complications. Uveitis and peripheral ulcerative keratitis were considered to be extensions of the inflammatory process and not to be true structural complications. Predictive factors of ocular complications were assessed using regression analysis. The impact of ocular complications on visual acuity—measured by best-corrected visual acuity (BCVA)—was also analyzed. Results: A total of 154 patients (218 eyes) with non-infectious scleritis were enrolled. In 58 of these patients (87 eyes), 102 ocular complications were recorded, with cataract, scleral and corneal thinning, and glaucoma and/or increased ocular pressure being the most frequently recorded complications. Ocular complications were found to be significantly more frequent among patients affected by granulomatosis with polyangiitis (GPA) (p < 0.0001) and concomitant uveitis (p = 0.023). The mean severity score was significantly higher among eyes experiencing ocular complications (p < 0.0001). Regression analysis identified three variables capable of predicting the development of ocular complications: a diagnosis of GPA [odds ratio (OR) 7.747, p < 0.0001]; the presence of concomitant uveitis (OR 3.648, p = 0.019); and a high severity score (OR 1.138, p = 0.044). Mean (± standard deviation) BCVA converted to logMAR was found to be significantly higher among eyes without ocular complications (0.12 ± 0.24 vs 0.27 ± 0.49; p = 0.005). Conclusion: Scleritis was accompanied by irreversible ocular complications in a considerable proportion of the patients enrolled in this study. Patients with a diagnosis of GPA, concomitant uveitis, and a higher severity score are more likely to develop ocular complications, and thus warrant a tighter follow-up schedule and early treatment in order to minimize the risk of poor visual prognosis.