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

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).

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.

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.

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.