Ocular and Genetic Risk Factors in Branch Retinal Vein Occlusion: a Comprehensive Review.

Introduction: Branch retinal vein occlusion (BRVO) is a leading cause of vision impairment globally and the second most common retinal vascular disease leading to blindness. Affecting over 20 million people worldwide, the prevalence of BRVO is expected to increase with the aging population. Branch retinal vein occlusion occurs due to the obstruction of small veins draining blood from the retina, leading to hemorrhages, fluid leakage and retinal damage. Its pathogenesis involves a complex interplay of ocular conditions and genetic predispositions.

Methods: A comprehensive literature search was conducted using PubMed and Google Scholar for articles published between January 2010 and January 2024. The search terms included "retinal vein occlusion", "BRVO" and "risk factors." After initial screening of 642 articles, non-English articles, animal studies and in vitro models were excluded. In total, 63 articles were analyzed for ocular and genetic risk factors associated with BRVO.

Results: Ocular risk factors for BRVO include glaucoma, short axial length and optic disc drusen. Elevated intraocular pressure in glaucoma can compress retinal veins, while short axial length increases the likelihood of venous compression. Optic disc drusen cause vascular anomalies that heighten BRVO risk. Genetic polymorphisms affecting coagulation, endothelial function, inflammation and oxidative stress, such as MTHFR C677T and Factor V Leiden, also influence BRVO susceptibility. Familial clustering and genetic variations in inflammatory pathways further contribute to the risk.

Conclusion: The significant impact of BRVO on vision health underscores the need for comprehensive strategies for early detection, prevention and treatment. Understanding the ocular and genetic risk factors is crucial for developing personalized treatment and effective public health initiatives. Ongoing research into genetic and molecular mechanisms will enhance management approaches and improve patient outcomes.