Aging studies on normal lens using the Scheimpflug slit-lamp camera

To study the changes in density and thickness in normal lenses related to aging, and to study changes in anterior chamber depth related to aging.

Eighty nine normal volunteers (ages 9-80 yr) were examined and their eyes were photographed to obtain Scheimpflug photographs. The images were digitized and linear densitometry was performed, dividing the lens into five areas: posterior capsular (area 1), posterior cortical (area 2), nuclear (area 3), anterior cortical (area 4), and anterior capsular (area 5). Total lens thickness and anterior chamber depth were similarly measured for 90 normal eyes from the densitometry profiles. These were correlated with age.

There was a strong positive correlation between increasing age and the density in all lens areas (area 2: r = 0.805; P < 0.0001; area 3: r = 0.836, P < 0.0001; area 4: r = 0.767, P < 0.0001; and area 5: r = 0.319, P < 0.0023), except the posterior capsular area, where correlation was negative (area 1: r = -0.426; P < 0.0001). In addition, there was a significant correlation between age and overall lens thickness (r = 0.756; P < 0.0001), thickness of nucleus (r = 0.543; P < 0.0001), and cortex (r = 0.632; P < 0.0001), and a negative correlation with anterior chamber depth (r = -0.513, P < 0.0001).

This report shows human lens changes in density and thickness correlated with aging using Scheimpflug photography and image analysis techniques. The results will aid future development of systems for automated detection, classification, and monitoring of human cataracts, as well as other anterior segment disorders.