A comparative study of post-operative pain in laser epithelial keratomileusis versus photorefractive keratectomy

Abstract

Background: To compare the level of post-operative pain associated with two methods of excimer laser corneal refractive surgery: PRK (photorefractive keratectomy) versus LASEK (laser epithelial keratomileusis).

Methods: 14 patients undergoing simultaneous bilateral myopic PRK were included in the study. The first eye of each patient was randomly allocated for treatment by either LASEK or PRK with alcohol-assisted epithelial debridement and second eyes were treated with the other technique. Laser corneal ablation was performed with Nidek EC-5000 excimer laser by one surgeon (MAA) using the same algorithm. Post-operatively, all patients had declofenac sodium 0.1% eye drops four times a day, lorazepam 2mg at night and two solpadol (paracetamol 500mg and codeine phosphate 30mg) tablets every six hours orally for two days. Chloramphenicol 0.5% drops four times a day were also administered for seven days. The level of pain in each eye was assessed 2, 12, 24 and 48 hours following laser surgery using a descriptive pain score from 0 to 10. Statistical analysis was performed using paired t test.

Results: The mean pain score at two hours post-operatively was 3.5 +/- 2.24(SD) in the LASEK group and 5.7 +/- 2.02(SD) in the PRK group. This difference is statistically significant. At 12 hours it was 4.33 +/- 2.53 (SD) and 4.75 +/- 2.30 (SD), at 24 hours it was 3.71 +/-2.84 (SD) and 4.00 +/- 2.48 (SD), and at 48 hours it was 2.86 +/- 3.43 (SD) and 2.21 +/- 2.55 (SD). There was no statistically significant difference in the pain score at these intervals.

Conclusions: Post-operative pain was less in eyes treated with LASEK than eyes treated with PRK 2 hours following laser surgery. This was statisticaly significant and there was no statistically significant difference at 12, 24 and 48 hours.