Abstract
Purpose: :
To evaluate early post-op healing following epithelial laser-assisted in situ keratomileusis (Epi-lasik), in terms of post-op pain, epithelial healing, visual recovery, and complication rates when compared to photorefractive keratectomy (PRK).
Methods: :
252 eyes of 126 active duty US Army soldiers, age 21 or over underwent Epi-lasik for myopia or myopic astigmatism using the AmadeusTM II epikeratome and LADARVisionTM 6000 excimer laser system. Pain, corneal epithelium, uncorrected vision (UCVA) and complications such as corneal infiltrates were assessed at 1 day, 4 days, and 1 week post-op. UCVA, best spectacle corrected visual acuity (BSCVA), and manifest spherical equivalent (MSE) were assessed at 1 and 3 months post-op. Epi-lasik data were compared to an existing PRK data set collected under identical conditions. Statistical analysis was performed using SPSS software version 15.0. A Mann Whitney test was performed to compare UCVA and pain between Epi-lasik and PRK. The Fisher’s exact test was performed to assess the difference between the two groups when examining re-epithelialization and the presence of corneal infiltrates. A P-value of < 0.05 was considered statistically significant.
Results: :
252 eyes with follow up at 1 day, 244 eyes at 4 days, and 226 eyes at 7 days, 166 eyes at 1 month, and 116 eyes at 3 months were analyzed. The mean age was 34 years old with 61.1% males. The mean preoperative MSE was -2.93 + 1.19 (range: -1.00 to - 6.25). There was no significant difference in pain scores between Epi-lasik and PRK at any visit in the first week post-op. Re-epithelialization was significantly faster in PRK eyes, with 92% of PRK eyes vs. only 55.3% of Epi-lasik eyes healed by post-op day 4 (P=0.00) and 99% of PRK vs. 88.5% of Epi-lasik eyes healed by post-op day 7 (P=0.00). 50 Epi-lasik eyes and no PRK eyes required an additional visit at 10 day post-op for complete re-epithelialization. Epi-lasik was associated with significantly worse UCVA at post-op day 1 (P=0.002) when compared to PRK. There was otherwise no significant difference in UCVA, BSCVA, or MSE post-op through 3 months post-op.
Conclusions: :
Epi-lasik was comparable to PRK in terms of post-op pain and vision, except for post-op day 1 where PRK eyes had significantly better UCVA. Epi-lasik eyes were significantly slower to re-epithelialize than PRK eyes. It remains to be seen how Epi-lasik compares to PRK in terms of final visual outcomes and corneal haze rates, but early healing following PRK is equal or superior to that following Epi-lasik in the first weeks post-operatively.
Clinical Trial: :
www.clinicaltrials.gov NCT00413517
Keywords: refractive surgery: PRK • refractive surgery: comparative studies • refractive surgery: other technologies