LASEK and Photorefractive Keratectomy for Myopia: Clinical and Confocal Microscopy Comparison

Abstract

PURPOSE: To compare postoperative visual acuity and corneal morphology after laser epithelial keratomileusis (LASEK) versus photorefractive keratectomy (PRK) in the correction of low to moderate myopia. METHODS: In a double-blind, randomized clinical trial, 50 myopic patients (mean: -4.5±1.35 diopters) were randomized to receive LASEK in one eye and PRK in the fellow eye. No mitomycin C eye drops were used in this study. Patients were observed daily for 4 days, then at 1 month and every 3 months up to 1 year. Uncorrected and best-corrected visual acuity (UCVA and BSCVA), manifest refraction, corneal epithelium healing time, postoperative pain, and corneal haze were evaluated. Corneal wound healing was quantified with corneal confocal microscopy. RESULTS: Refractive error, UCVA, and BSCVA were not statistically different between eyes treated with LASEK and PRK. Corneal epithelium healing time was 2.52±0.99 days in the eyes treated with PRK and 2.29±0.52 days in the eyes treated with LASEK (P =.22). The postoperative pain score was 2.17±0.87 in the eyes treated with PRK and 2.62±0.60 (P = .02) in the eyes treated with LASEK. Corneal confocal microscopy showed fewer stromal activated keratocytes and less extracellular matrix deposition in the eyes treated with LASEK than in the eyes treated with PRK at 1 month postoperatively (P = .003). CONCLUSIONS: LASEK is an effective and safe procedure for low to moderate myopia, but it seems more painful until full corneal reepithelization. In the early postoperative period, the corneal wound healing process is significantly less intense in eyes treated with LASEK than in eyes treated with PRK. The role of LASEK in corneal wound healing modulation remains controversial. [J Refract Surg. 2007;23:694-702.]

A Clinical and Confocal Microscopic Comparison of Transepithelial PRK and LASEK for Myopia

“…Previous studies have also reported higher grades of haze after traditional PRK compared to LASEK, particularly in the early postoperative months [1–3, 13]. Similar to our results, Ghirlando et al [3] reported a less intense wound healing process after LASEK than after traditional PRK, documented with confocal microscopy.…”

Corneal Density with the Pentacam After Photorefractive Keratectomy

“…16 Subsequent developments in refractive surgery (PRK, LASIK, laser epithelial keratomileusis [LASEK], epi-LASIK, femto-LASIK, and mitomycin C treatment) have resulted in increasingly better and faster wound healing after both hyperopic and myopic procedures. 5,6,[17][18][19][20] Along with this, the magnitude of stromal opacities in surgeries with newer laser technology has notably diminished. However, new techniques may cause new types of wound healing processes and haze formation, which need to be standardized and quantifi ed.…”

Effect of repositioning or discarding the epithelial flap in laser-assisted subepithelial keratectomy and epithelial laser in situ keratomileusis

“…Moreover, the decision to reposition or to remove the epithelial flap seems a crucial difference, and some studies comparing the 2 methods have been performed. 35,38,[48][49][50] Prospective clinical studies comparing techniques are shown in Table 3 30,[38][39][40]44,46,47,[51][52][53][54][55][56][57] and laboratory studies in Table 4. 32,58,59 However, these studies yielded partly contradictory conclusions.…”

“…Potential differences in surface ablation techniques may be more obvious with higher degrees of correction, as reported years ago. [55][56][57][67][68][69] (4) Between the 4 groups, each consisting of 20 eyes, we performed 9 comparison tests at 1, 2, and 4 days and 21 comparison tests at 3 months. A P value less than 0.05 was considered statistically significant in this study, which corresponds In epi-LASIK, the lamina densa and lamina lucida were preserved and the hemidesmosomes had normal morphology.…”