Delayed Corneal Epithelial Wound Healing after Excimer laser Photorefractive Keratectomy

ABSTRACT

The purpose of this study was to evaluate the occurrence of delayed epithelial healing(DEH) and the factors associated with it after excimer laser photorefractive keratectomy(PRK) and to assess whether there are any difference in the clinical outcomes between the eyes of DEH group and normal epithelial healing(NEH) group. This retrospective study was done in 554 consecutive eyes which had eximer laser PRK(VISX 20/20B WisionKey system with central island removal program) by one surgeon(S.B.L) between September 1994 and April 1997 at Yeungnam University Medical Center. Mean reepithelializion time of all 554 eyes was 3.1+/-1.3 days. Delayed epithelial healing beyond postoperative 5 and 7 days after exicimer laser PRK were noted in 30 eyes(5.4%) and 8 eyes(1.4%) of all 554 eyes, respectively. Mean reepithelialization time of DEH group was 7.1 days(range 5~12 days). Occurrence of DEH after excimer laser PRK was not depending on sex, age, laterality, amount of attempted correction(-6D or -6D), type of procedure(PRK vs. PARK), use of Maclof, the order of operation(type eye vs. second eye) or the type of soft ware(version 3.20 vs. 4.01)(All p>0.05). At 6 months after surgery, 16 eyes(64%) of total 25 eyes of DEH group achieved UCVA of 0.7 or better, and 14 eyes(56%) were within +/-1D of emmetropia. In the NEH group. 349 eyes(84.7%) were UCVA of 0.7 or better, and 365 eyes(88.4%) were within +/-1D of emmetropa. There was statistically significant decrease in the clinical outcome of DEH group being compared with NEH group(p<0.05) In conclusion, prompt management for complete epithelial wound healing should be done in the cases of delayed epithelial healing after excimer laser PRK because it can cause the decrease in clinical outcome. Further studies assessing the effects of numerous topical medications, preservatives and software on epithelial healing after exicimer laser PRK would be performed.