Moyamoya Disease increased the risk of Retinal Vascular Occlusion: A Nationwide Cohort Study in Korea.

Purpose: To investigate the risk of retinal vascular occlusion in patients with Moyamoya disease (MMD).

Design: Retrospective, longitudinal cohort study using the Korean National Health Insurance Service database.

Participants: Newly diagnosed MMD patients (n=34,627), who were diagnosed between 2004 and 2022, and their propensity score matched controls (n=136,945) were included.

Methods: We identified retinal vascular occlusion events using diagnostic codes for central retinal artery occlusion, other retinal artery occlusion, and retinal vein occlusion. After a washout-period from 2002 to 2003, information on the diagnosis of retinal vascular occlusion was extracted in both MMD and control group during the follow up period. The association between MMD and the risk of subsequent retinal vascular occlusion was investigated using a time-dependent Cox proportional hazard model and Kaplan-Meier survival analysis with log-rank test adjusted for age, sex, and comorbidities.

Main outcome measures: Hazard ratios (HRs) and 95% confidence intervals (CIs) for retinal vascular occlusion development according to the MMD.

Results: MMD was associated with an increased risk of subsequent retinal vascular occlusion even after adjusting for confounding variables (HR, 1.22; 95% CI, 1.09-1.36). Among the subtypes of retinal vascular occlusion, central retinal artery occlusion showed a highest HR (2.23; 95% CI, 1.35-3.7). Incidence probability of retinal vascular occlusion was significantly higher among MMD patients than controls (P < 0.001, log-rank test).

Conclusion: In this nationwide population-based cohort study, patients with MMD in Korea had an elevated risk of retinal vascular occlusion, suggesting that the MMD is one of the risk factors for retinal vascular occlusion.