Antioxidant protection against corneal damage by free radicals during phacoemulsification.
OBJECTIVE
To examine the role of ascorbic acid in reducing corneal endothelial cell loss secondary to high-energy ultrasound energy 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 nine eyes, a balanced salt ophthalmic solution was used as the phacoemulsification irrigation solution, and in eight eyes the solution plus 0.001 M ascorbic acid was used, all other parameters being identical between the two groups. Specular microscopy was performed in all eyes before and 1 week after surgery. The animals were then killed, and the corneas were examined histologically.


RESULTS
There was no significant difference in preoperative endothelial cell counts between the two groups. Postoperative cell counts were reduced by 453.9 +/- 233.3 (SEM) cells/mm(2) in the solution-alone group versus 123.2 +/- 196.4 (SEM) cells/mm(2) in the solution-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 irrigation solution significantly reduced the amount of endothelial cell loss during phacoemulsification by approximately 70%. This is thought 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.
Rubowitz
Alexander
A
Department of Ophthalmology, Meir Hospital, Sapir Medical Center, Kfar-Saba, Israel. aldoc@netvision.net.il
Assia
Ehud I
EI
Rosner
Mordechai
M
Topaz
Morris
M
D000085:Acetates; D000818:Animals; D000975:Antioxidants / Q000627:therapeutic use*; D001205:Ascorbic Acid / Q000627:therapeutic use*; D002452:Cell Count; D003316:Corneal Diseases / Q000209:etiology / Q000517:prevention & control*; D019610:Cytoprotection / Q000187:drug effects; D004338:Drug Combinations; D004728:Endothelium, Corneal / Q000187:drug effects* / Q000473:pathology; D005260:Female; D016166:Free Radical Scavengers / Q000627:therapeutic use*; D005609:Free Radicals / Q000633:toxicity; D008903:Minerals; D018918:Phacoemulsification / Q000009:adverse effects*; D011817:Rabbits; D012965:Sodium Chloride
D000085:Acetates; D000975:Antioxidants; C030660:BSS solution; D004338:Drug Combinations; D016166:Free Radical Scavengers; D005609:Free Radicals; D008903:Minerals; D012965:Sodium Chloride; D001205:Ascorbic Acid