Effect of Gentamicin and Chloramphenicol on Bovine Lens Optical Function During Culture

Abstract

Lens refractive function was monitored during long-term bovine lens culture experiments in which low concentrations of potentially damaging agents were added to the culture media. The agents tested were the antibiotics gentamicin and chloramphenicol. Both are injected intravitreally in patients with endophthalmitis. A computer-driven scanning laser system was used to monitor lens focusing behavior during culture. The system consists of a scanning helium-neon laser beam, a video camera, and a video frame digitizer. The system first locates the optical center of the lens, defined as the position of little or no refractive deviation of the beam. The laser scans the lens in small steps (0.7 mm), while the digitizer measures focal length for each beam position. A graphic profile of lens focal variation is plotted. A concentration of 0.5 mg/ml gentamicin produced an increase in the variability of focal length sharpness of focus after about 450 hr of incubation. When the concentration is increased 10-fold (5 mg/ml) the sharpness of focus decreases earlier (between 50 and 95 hr). Chloramphenicol in a concentration of 2 mg/d disrupts lens focal ability after 450 hr of culture. Lenses placed in 20 mg/ml chloramphenicol for only 10 min developed marked changes in focal variability after 600 hr of culture.