Automated biometry and densitography of anterior segment of the eye

Abstract

Twenty-eight fresh donor eyes (Georgia Lions Eye Bank), ranging in age from 4 months to 87 years, were utilized for an in vitro study to determine the feasibility of obtaining accurate AC diameter measurements with our Scheimpflug UV-visible slit lamp densitography apparatus. The in vivo study was performed on 16 hybrid monkeys (of varying age). These data were within 0.1 mm of measurements obtained with a modified paracentesis needle specially designed to obtain such measurements (sensitivity within 0.01 mm). The results of the foregoing study demonstrate that Scheimpflug slit lamp photographic analysis can measure the AC diameter accurately without entering the globe surgically. This will enable the surgeon to determine the AC diameter and order an anterior chamber IOL of a specified size prior to surgery. We have devised an automated program to analyze the negatives and provide direct AC diameter measurements. In addition, this program can provide other data including: (1) radius of curvature of anterior and posterior cornea and corneal thickness; (2) depth of anterior chamber; (3) radius of curvature of anterior and posterior lens surfaces and lens thickness; and (4) densitographic analysis of cornea and lens with UV as well as visible light, thus providing fluorescence data for these two tissues as well.