control-matched comparison of flap off and flap on laser-assisted subepithelial keratectomy [LASEK] for the treatment of myopia and myopic astigmatism

Purpose: To compare the visual and refractive outcomes of flap off and flap on, Laser Assisted Subepithelial Keratectomy [LASEK] for low to moderate myopia

Methods: A prospective non-randomized control-matched study was conducted in which 53 patients underwent LASEK for the treatment of low to moderate myopia and myopic astigmatism. Right eye of each patient had the flap removed [flap off] while in the left eye the flap was recapped [flap on]. Equal number [N = 53] of flap on was matched with flap off having preoperative manifest refraction spherical equivalent within +/- 0.75 Diopters [D]. Primary outcome variables included uncorrected visual acuity [UCVA], best spectacle-corrected visual acuity [BSCVA] and manifest refraction

Results: Preoperatively, the mean spherical equivalent [SE] was -3.59 +/- 1.46 D for flap off and -3.67 +/- 1.51 D for flap on [p = 0.779]. The mean preoperative sphere was -3.32 +/- 1.58 D for flap off group and -3.36 +/- 1.61 D for flap on group [p = 0.338] whereas, the mean preoperative cylinder was -0.55 +/- 0.70 D and -0.63 +/- 0.68 D for flap removal and flap preservation groups respectively [p = 0.576]. Postoperatively, the mean LogMAR UCVA was -0.035 +/- 0.079 for flap off and -0.043 +/- 0.085 for flap on. The percentages of eyes that had UCVA of 20/40 or better were 98.1% for flap off group and 100% for flap on group [p = 0.317]. Mean postoperative SE was 0.00 +/- 0.19 D for flap off group and -0.03 +/- 0.43 D for flap on group. In flap removal group, 100% eyes were within +/- 0.50 D of the intended correction while in flap preservation group, 92.5% and 100% eyes were within +/- 0.50 D and +/- 1.00 D of the intended correction, respectively. Mean postoperative LogMAR BSCVA was -0.013 +/- 0.044 for flap removal group and -0.016 +/- 0.049 for flap preservation group [p = 0.727]

Conclusions: The differences in the visual and refractive results between flap preservation and flap removal groups were not clinically significant. Both procedures seemed safe and effective for the treatment of myopia and myopic astigmatism

Hemilimbal deficiency model of corneal neovascularization: Possible invalidity of the limbal barrier concept

To describe a novel model of corneal neovascularization [NV] in mouse cornea where hemilimbal deficiency is induced with or without corneal epithelial debridement. Following hemilimbal excision with or without corneal epithelial removal, mice corneas were examined and photographed prior to and following the onset of corneal NV. Slides were reviewed by visual observation for evidence of corneal NV. Corneas with complete removal of both limbus and epithelium [group I; n=10] all developed extensive corneal NV by post-operative days [POD] 3-10. Corneas with intact epithelium and complete removal of the limbus [group II; n=7] developed corneal NV by POD's 7 [n= 6] or 30 [n= 1]. Corneas where half of the limbus and more than half of the corneal epithelium were removed [group III; n= 9] developed vessels from the side opposite to the limbal injury by POD's 4-7. Corneas where half of the limbus removed and only the adjacent peripheral corneal epithelium were removed did not show any vessels [group IV; n= 9]. Removal of half of the limbus [hemilimbal deficiency] led to corneal NV from the opposite side of the cornea, in which the limbus was intact, raising question about the function of Limbus as a harrier to corneal NV

efficacy, predictability, and safety of Epi-Lasik for the correction of myopia

To report the refractive and visual results of epithelial laser in situ keratomileusis [Epi-LASIK] for the treatment of myopia. Retrospective non-comparative consecutive case series. Sixty nine eyes of 40 patients had Epi-LASIK for the treatment of low myopia or myopic astigmatism. All epithelial separations were performed with the Visijet/Gebauer microkeratome. Primary outcome variables included uncorrected visual acuity [UCVA], best spectacle-corrected visual acuity [BSCVA], manifest refraction, epithelization time, pain, haze and complications. Preoperatively, the mean spherical equivalent [SE] was -3.9 diopters [D] +/- 1.6 D [range -.75 to -7.00 D] and the mean LogMAR BSCVA was 0.0131 +/- 0.04l [range -0.10 to 0.12]. On the final visit, the mean SE was -0.27+0.53D [range -2.50 to 0.50D], the mean logMAR UCVA was -0.079 +/- 0.13 [range -0.48 to 0.12] and the mean LogMAR BSCVA was 0.0039 +/- 0.053 [range -0.18 to 0.1]. 95.1% of eyes achieved a vision of 20/40 or better, and 70.5% achieved a vision of 20/25 or better. 73.8% and 95.1% of eyes were within +0.5D and+1.0D, respectively. Complete epithelialization occured in 6.2 +/- 1.4 days [range 3 to 8 days]; 93.4% of eyes had clear corneas or only trace haze at the final postoperative visit; 94.7% of eyes had no or minimal pain. Epi-LASIK is a safe, effective and predictable method for the treatment of low to moderate myopia and myopic astigmatism