Cross-sectional study of ocular optical components interactions in emmetropes

Purpose of the paper was to evaluate ocular optical components (OOC) interactions in a large number of emmetropes. A cross-sectional study of 1,000 emmetropes, aged from 18-40 years, has been conducted. Complete ophthalmological examination, corneal radius (CR) measurement, keratometry and echobiometry of both eyes were performed. The highest correlation of OOC was that of axial length (Ax) with vitreal body (CV) on both eyes (r = 0.79 for the right eye (RE); r = 0.81 for the left eye (LE)). The axial length had a positive correlation with the anterior chamber depth (ACD) on both eyes as well, but the coefficient was very low (r = 0.29 for the RE; r = 0.32 for the LE). The only negative correlation Ax had on both eyes was with the lens (L) (r = -0.17 for the RE; r = -0.19 for the LE). Keratometry of the horizontal (K1) and vertical meridian (K2) showed a negative correlation with CV and Ax on both eyes (for K1 r = -0.64 for CV r = -0.54 for Ax; for K2 r = -0.67 for CV r = -0.68 for Ax). CR had a positive correlation with Ax (r = 0.74) and CV (r = 0.79). It showed a negative correlation with L (r = -0.58). CV had a high, positive correlation with Ax (r = 0.72 for the RE; r = 0.75 for the LE). The correlation with K1 and K2 was negative. Our study showed that the axial length, keratometry, corneal radius, lens thickness and vitreal body were the most important OOC that correlated with each other following a pattern in our group of emmetropes. They interacted in such a way that in the subjects with axial length above the average value, the vitreal body was longer but the lens was thinner and the cornea was of less power. This could explain at least one of the mechanisms of emmetropization.