Correlation between epithelial ingrowth and basement membrane remodeling in human corneas after laser-assisted in situ keratomileusis.

OBJECTIVE: To further investigate the hypothesis that epithelial ingrowth in human corneas after laser-assisted in situ keratomileusis (LASIK) correlates with basement membrane remodeling, as suggested by the presence of matrix metalloproteinase 9 around epithelial cells in the lamellar scar. METHODS: Immunohistochemical analysis and transmission electron microscopy were applied to human postmortem corneas with post-LASIK epithelial ingrowth. RESULTS: Epithelial ingrowth into the flap margin was observed in 8 of 18 corneas (44%). Matrix metalloproteinase 9 immunolocalized around ingrown epithelium in 6 of these 8 corneas (75%). There was a positive correlation between the presence of matrix metalloproteinase 9 at the wound margin and discontinuities in the basement membrane, as determined by laminin and beta(4) integrin immunofluorescence. Transforming growth factor beta2 was present into the stroma of some corneas with epithelial ingrowth and interrupted basement membrane, suggesting some degree of epithelial-stromal interaction. Transmission electron microscopy confirmed large areas of remodeled basement membrane along ingrown epithelial cells. CONCLUSIONS: The neo-basement membrane components underlying the ingrown cells in human corneas with epithelial ingrowth after LASIK appear to be partially disassembled. Epithelial-stromal interaction over time may be related to prolonged wound healing remodeling, which calls into question the stability of the flap.

A randomized paired eye comparison of two techniques for treating moderately high myopia: LASIK and artisan phakic lens.

OBJECTIVE: To compare refractive performance and safety of laser in situ keratomileusis (LASIK) and Artisan phakic intraocular lens (PIOL) for moderately high myopia. DESIGN: A prospective, randomized trial with paired eye control. PARTICIPANTS: Twenty-five patients with myopia ranging from -8.00 to -12.00 diopters (D). INTERVENTION: For each patient, one eye received LASIK and the other one was implanted with an Artisan phakic intraocular lens. The treated eye and the surgical technique were randomized. MAIN OUTCOME MEASURES: Primary outcome measure was spherical equivalent refraction. Main secondary outcome measures were the change of two or more lines and safety index (ratio postoperative to preoperative best-corrected visual acuity). RESULTS: One year after surgery, the mean spherical equivalent refraction was -0.74 +/- 0.67 D for LASIK-treated eyes and -0.95 +/- 0.45 D for Artisan-treated eyes, and the majority of LASIK-treated eyes (64%) and Artisan-treated eyes (60%) were within +/-1.00 D of the intended result. At 1 month, the mean spherical equivalent refraction was -0.28 +/- 0.71 D for LASIK and -1.07 +/- 0.59 D for Artisan (P < 0.01). The changes of two or more lines were in favor of Artisan (P < 0.05). The safety index was significantly better for Artisan (1.12 +/- 0.21) than for LASIK (0.99 +/- 0.17) at 1 year (P < 0.02). CONCLUSIONS: In cases of moderately high myopia, LASIK and Artisan phakic intraocular lenses seemed to produce a similar predictability. The best-corrected visual acuity and subjective evaluation of quality of vision were better for Artisan.