Mitomycin-C Aqueous Humor Concentration in Rabbit after PRK or TPRK for -3D, -6D or -9D Treatment

Abstract

Purpose : To evaluate mitomycin-C (MMC) aqueous humor concentration after photorefractive keratectomy without epithelial removal (PRK) or Transepithelial PRK (TPRK)

Methods : In this experimental study, thirty eyes of 15 male New Zealand white rabbits (2.5-3kg, 3 months) were divided into 3 groups to correct -3 diopters (D), -6D, -9D respectively with 6-mm optical zone, each rabbit was randomized underwent PRK without epithelial removal (PRK) in one eye and TPRK on the other. Sponges soaked with 0.02% MMC were applied on the exposed corneal stroma for 120 seconds. Aqueous humor was withdrawn from all rabbit eyes 10 minutes after MMC application and high-performance liquid chromatography was performed to detect and quantify MMC levels. Wilcoxon’s sign rank test and Spearman rank correlation statistical methods were used for statistical analysis.

Results : The mean MMC aqueous humor concentration in groups 1, 2 and 3 were 0.123±0.044 μg/ml, 0.222±0.053 μg/ml, 0.344±0.121 μg/ml respectively for PRK eyes; and 0.412±0.152 μg/ml, 0.431±0.141 μg/ml, 0.660±0.173μg/ml respectively for TPRK eyes. Significant difference was found between PRK and TPRK in each group (p<0.05). Correlation between aqueous MMC concentration and residual cornea thickness were negative in PRK (r= -0.743; p= 0.001) and TPRK (r= -0.554; p= 0.032). Aqueous concentration of MMC increased linearly with decreased residual cornea thickness.

Conclusions : MMC aqueous humor concentration was correlated negatively with residual cornea thickness. Reserving more residual cornea thickness would be good for reducing the potential MMC toxicity.

This is an abstract that was submitted for the 2017 ARVO Annual Meeting, held in Baltimore, MD, May 7-11, 2017.