Lens Position and Age: The Central India Eye and Medical Study.

Abstract

We assessed changes in the position of the lens with aging in a general population. The population-based Central India Eye and Medical Study included 4711 subjects. As part of an ophthalmic examination, anterior segment length (ASL) was measured sonographically and calculated as anterior chamber depth plus lens thickness. Subjects with nuclear cataract grades 5 or more (43.9% of the sample) were excluded. The study included 2468 subjects (1176 [47.6%] men) with a mean age of 41.2 ± 8.5 years (range, 30-78 years) and mean axial length of 22.68 ± 0.81 mm (range, 19.89-31.02 mm). In multivariate analysis, longer ASL was associated with older age (P = 0.04; correlation coefficient B, 0.002; 95% confidence interval [CI], 0.000, 0.005) after adjusting for male sex (P < 0.001), longer axial length (P < 0.001), higher degree of nuclear cataract (P = 0.001), and higher body mass index (P = 0.02). Greater lens thickness was associated with older age (P < 0.001; B, 0.009; 95% CI, 0.007, 0.0011) after adjusting for male sex (P < 0.001), shallower anterior chamber depth (P < 0.001), and higher degree of nuclear cataract (P < 0.001). Deeper anterior chamber depth was associated with younger age (P < 0.001; B, -0.007; 95% CI, -0.008, -0.005) after adjusting for male sex (P < 0.001), thinner lens thickness (P < 0.001), and longer axial length (P < 0.001). Combining both analyses revealed that for each year increase in age, lens thickness increased by 0.009 mm, anterior chamber depth decreased by 0.007 mm, the posterior lens pole moved backward by 0.002 mm, and the lens center moved forward by 0.0025 mm. Increasing age before the development of cataract is associated with a slight forward movement of the lens center, adding to the lens paradox.