Purpose. To determine if zinc, which blocks apoptosis in many systems, including leukemic cells and possibly in retinal dystrophies, can prevent the unwanted loss of anterior stromal keratocytes after superficial keratectomy. Methods. After central 8 mm corneal epithelial debridement with a blade, the left eyes of 9 New Zealand white rabbits (2.0-2.5 kg) were treated with 25 mM ZnCl2 in MEM Earle's salts culture medium (Irvine Scientific) every 30 minutes (n=3), every 2 hours (n=3), and every 4 hours (n=3). Nine eyes of different animals, divided into 3 equal groups, were de-epithelialized and received pure culture medium at respective frequencies. Another 6 eyes were de-epithelialized and received no drops. After 24 hours, the animals were sacrificed, globes were enucleated, corneas were processed, and sections were stained with hematoxylin and eosin. Keratocytes in three half-40x high power fields were counted per histologic section. Results. The cell count of MEM-treated corneas exceeded that of untreated corneas (p=0.02), but there was no difference between frequencies of MEM application (p=0.36, ANOVA). Cell counts increased with frequency of zinc application, but differences were not statistically significant (p=0.09, ANOVA). Only in the group receiving the highest frequency of zinc were superficial keratocytes retained. This group also possessed a greater number of stromal keratocytes than MEM-treated corneas and untreated controls (p<0.05). Conclusions. At the highest dosage, zinc can prevent loss of superficial keratocytes more than does culture medium alone. Moreover, zinc has the advantage of preserving the most anterior layer of keratocytes. Retention of these cells may prevent reactive overproliferation most likely responsible for haze seen after photorefractive surgery.
|Original language||English (US)|
|Journal||Investigative Ophthalmology and Visual Science|
|State||Published - Feb 15 1996|
ASJC Scopus subject areas
- Sensory Systems
- Cellular and Molecular Neuroscience