Research of lens parameter on pathogenesis of primary angle closure glaucoma via ultrasound examination

Abstract

Objective To research lens parameters in the pathogenesis of primary angle closure glaucoma (PACG).Methods Of 40 acute PACG in-patients (80 eyes),40 chronic PACG ones (80eyes) and 40 healthy individuals with wide chamber angle (80 eyes),parameters of ocular anterior segment were calculated and correlation analyzed among the lens parameters,anterior chamber depth and parameters of anterior chamber angle by B ultrasound,self-developed computer image processing software and ultrasound biomicroscope (UBM).Results Compared with the normal group,PACG had thicker lens,steeper anterior surface curvature of lens and relatively more anterior lens position,among which there were statistically significant differences (P ＜0.01),but no significant differences among the lens diameter,lens volume and the curvature radius of posterior lens surface (P ＞0.05).For PACG,both the curvature radius of anterior lens surface and relative position of lens had moderately positive correlation with anterior chamber depth,angle open distance at 500μ m and trabecular iris angle (TIA)(P ＜0.01).Conclusions The PACG pathogenesis show relevance to the abnormalities of lens anatomical structures,including the thicker lens,steeper curvature of anterior lens surface,and the relative more anterior position of lens.Lens diameter,its volume and its curvature of posterior surface do not confirm correlation with PACG.Compare with that of acute PACG,anterior segment of chronic PACG crowd relatively less. Key words: Primary angle closure glaucoma; Lens; Pathogenesis