Analysis of Clinical Characteristics and Posterior Segment Parameters in Multiple Sclerosis-Associated Uveitis with Optical Coherence Tomography Angiography.

Purpose: To describe the clinical characteristics of multiple sclerosis-associated uveitis (MSAU), to examine its relationship with multiple sclerosis (MS), using optical coherence tomography angiography (OCT-A) and spectral-domain optical coherence tomography (SD-OCT) parameters of patients.

Methods: The study included 58 eyes of 29 patients with MSAU, 102 eyes of 55 patients with MS, and 41 eyes of 41 healthy controls (HC). The eyes were divided into four subgroups depending on history of optic neuritis (MSON+, MSAUON+, MSON-, MSAUON-). All underwent OCT-A and SD-OCT. The data collected from MS, MSAU and control groups was compared.

Results: In MS patients, intermediate uveitis was the most common type of uveitis (41.4%). In unilateral MSON+ patients; a significant decrease was observed in the radial peripapillary capillary plexus (RPC), superficial capillary plexus (SCP), pRNFL and macular thickness in the ON+ eye compared to the healthy eye (p < 0.05). In ON- eyes, SCP density was found as control group, MS, and MSAU, respectively, from highest to lowest (p < 0.005). In the MSAUON- group; SCP, deep capillary plexus density (DCP) were significantly decreased compared to MS and control groups (p < 0.005). Macular thickness was decreased in the MSON- group compared to the control group (p < 0.005).

Conclusion: Intermediate uveitis is the most common form of uveitis in MS patients. Optic neuritis causes a decrease in SCP, RPC, RNFL, and macular thickness, it does not create a significant change in DCP. The diffuse reduction in all retinal capillary plexus layers in MSAU may accelerate the neurodegenerative process in ganglion cells.