Effects of short oxidative stress exposure on lens epithelial cells

Abstract

PurposeTo observe the reactions of lens epithelial cells (LECs) to a short exposure of an elevated oxidative stress. To help find future treatments for the prevention of posterior capsule opacification. Using cultured human lens capsules as an experimental model and hydrogen peroxide (H2O2) as the stress inducer.MethodsLens capsule‐ciliary body complexes were extracted from human donor eyes. Samples were exposed to 30 mM H2O2 for 5 min (n = 8) or used as untreated controls (n = 9). H2O2 was applied after lens extraction through intercapsular irrigation using a silicone irrigation ring. Samples were cultured on average for 30 days, during which dark field and lateral illumination photos were taken every 2–3 days. These photos were used to observe and quantify, time until cellular growth and subsequent confluence on the posterior capsule. Three of the controls were not cultured, in order to observe starting conditions.ResultsAll control samples showed signs of normal cellular growth on the posterior capsule on average by day 6. LEC proliferation and migration was not observed on H2O2 samples until day 22. Four H2O2 samples showed signs of growth. The overall delay of cell growth compared to control was significant (H2O2 p < 0.001). Until day 29 none of the exposed samples that had shown growth reached confluence. Half of controls were confluent on day 10, 83% on day 20 and all by day 26. The average cellular migration speed of controls and H2O2 samples were very similar, being 3.2 and 3.0 (mm2/day) respectively.ConclusionsExposure of lens epithelial cells to an elevated concentration of H2O2 for a short period of time does not seem to lead to immediate cell death as expected, but rather arrests the cell cycle. Surprisingly, after cells have recovered from the oxidative stress, they grow at a normal rate.