Ascorbic Acid Protects Corneal Endothelium from Damage Induced by Free Radicals during Phacoemulsification 0

Abstract

Abstract: : Purpose: To examine the role of ascorbic acid in reducing corneal endothelial cell loss secondary to high- intensity ultrasound energy (HIUE) during phacoemulsification surgery. Methods: Seventeen rabbit eyes were subjected to prolonged phacoemulsification within the anterior chamber, without manipulation or damage to other ocular structures. In 9 eyes Balanced Salt Solution (BSS) was used as the phacoemulsification irrigating solution, while in 8 eyes BSS with 10^-3 M ascorbic acid was used. All other parameters being identical between the two groups. Specular microscopy was performed prior to, and one week post-surgery. The animals were then sacrificed and the corneas were examined histologically. Results: There was no significant difference in pre-operative endothelial cell counts between the two groups. Post-operative cell counts were reduced by 453.9 ± 233.3 (SEM) cells/mm² in the BSS group versus 123.2 ± 196.4 (SEM) cells/mm² in the BSS plus ascorbic acid group, (p=0.011). Corneal histology revealed a marked difference in endothelial cell morphology between the two groups. Conclusions: The addition of ascorbic acid to the irrigating solution significantly reduced the amount of endothelial cell loss during phacoemulsification by about 70%. We believe this to be due to the free radical scavenging properties of ascorbic acid. Further studies are warranted to find the optimal concentrations and combinations of free radical scavengers to be used in phacoemulsification irrigation solutions.

Keywords: antioxidants • cataract