Analysis of LOXL1 gene variants in Japanese patients with branch retinal vein occlusion

PURPOSE: Previous studies have described a possible association between exfoliation syndrome (EX) and various ocular and systemic vascular disorders; however, the association between EX and branch retinal vein occlusion (BRVO) remains unclear. Because slit-lamp examination may overlook latent deposits of exfoliation materials, an ocular biopsy is usually needed for a precise diagnosis. We evaluated a possible association between EX and BRVO using lysyl oxidase-like 1 (LOXL1) gene variants as alternative markers for EX. METHODS: Allelic and genotypic frequencies of three LOXL1 variants (rs1048661, rs3825942, and rs2165241) were determined for 78 consecutive Japanese patients with BRVO (11 patients with exfoliation syndrome [EX+], 67 patients without exfoliation syndrome [EX-]), and 158 patients with cataract without EX (CT) as controls. RESULTS: The rs1048661 variant differed between the BRVO and CT groups in allelic and genotypic frequencies (p=0.0137 and p=0.0203, respectively). Subgroup analysis, compared to the CT group, showed that BRVO EX+ had significantly different allelic and genotypic frequencies of rs1048661 (p=0.00011 and p=0.000189, respectively), while BRVO EX- did not (p=0.175 and p=0.288, respectively). The frequencies of rs3825942 and rs2165241 did not differ between the BRVO and CT groups. CONCLUSIONS: No association was found between BRVO and EX if LOXL1 variants were used as disease markers for clinically undetectable EX. The results suggested that LOXL1 variants, well established markers for EX, are not likely genetic markers for BRVO in Japanese subjects.