Lack of Association Between Primary Angle-Closure Glaucoma Susceptibility Loci and the Ocular Biometric Parameters Anterior Chamber Depth and Axial Length

PURPOSE. Three susceptibility loci for primary angle-closure glaucoma (PACG) were recently identified: PLEKHA7 rs11024102, COL11A1 rs3753841, and rs1015213 located in the intergenic region between PCMTD1 and ST18. The purpose of this study was to investigate the associations of these loci with the ocular biometric parameters anterior chamber depth (ACD) and axial length (AL). METHODS. Genotype and ocular biometric data were available for four population-based studies, including three from Singapore (Singapore Chinese Eye Study, Singapore Malay Eye Study, and Singapore Indian Eye Study) and one from China (Beijing Eye Study), exceeding 7000 participants. ACD and AL were measured using the IOLMaster for the Singapore cohorts and optical low-coherence reflectometry (Lenstar 900 Optical Biometer) for the Beijing cohort. Five readings were obtained for each participant and the average was computed. Analysis excluded any eye that was pseudophakic or aphakic. RESULTS. ACD measurements and genotype data of the three loci were available for 7245, 7243, and 7239 subjects, respectively. We noted nominal evidence of association between single nucleotide polymorphism (SNP) rs1015213 (PCMTD1-ST18) and a shallower ACD when all data were meta-analyzed (beta = -0.033, P = 0.021). When multiple testing was considered, the observation was nonsignificant. There was no association between ACD and rs11024102 (PLEKHA7) or rs3753841 (COL11A1). We did not observe significant associations between AL and any of the three SNPs. CONCLUSIONS. The lack of association between the PACG susceptibility loci with ACD or AL suggests that predilection to PACG may be mediated by factors other than shallow anterior chamber or short eyeball length.