BACKGROUND: After excimer laser photorefractive keratectomy, corneal epithelial and anterior stromal wound healing may produce corneal haze and variability in refractive results among patients and eyes. METHODS: We report a retrospective study of 17 selected eyes that received excimer laser photorefractive keratectomy with one of three brands of laser and that exhibited regional variations in corneal wound healing as observed with slit-lamp microscopy and videokeratography (Tomey TMS) within the ablation zone. RESULTS: All 17 eyes were selected to show that the clear areas in the ablation zone corresponded with flat zones on the videokeratographs and the areas of subepithelial haze corresponded with steeper zones. Spectacle-corrected visual acuity was measured in 12 or the 17 eyes, and was 20/20 or better in 58% and 20/30 or better in 100%, indicating that the regional variation did not severely degrade Snellen visual acuity. Further studies are needed to determine how often regional variability occurs and to better define the relationship of corneal haze and corneal curvature. CONCLUSION: Regional variations in corneal topography and haze can occur within the ablation zone in an individual cornea after photorefractive keratectomy.
BACKGROUND: After excimer laser photorefractive keratectomy, corneal epithelial and anterior stromal wound healing may produce corneal haze and variability in refractive results among patients and eyes. METHODS: We report a retrospective study of 17 selected eyes that received excimer laser photorefractive keratectomy with one of three brands of laser and that exhibited regional variations in corneal wound healing as observed with slit-lamp microscopy and videokeratography (Tomey TMS) within the ablation zone. RESULTS: All 17 eyes were selected to show that the clear areas in the ablation zone corresponded with flat zones on the videokeratographs and the areas of subepithelial haze corresponded with steeper zones. Spectacle-corrected visual acuity was measured in 12 or the 17 eyes, and was 20/20 or better in 58% and 20/30 or better in 100%, indicating that the regional variation did not severely degrade Snellen visual acuity. Further studies are needed to determine how often regional variability occurs and to better define the relationship of corneal haze and corneal curvature. CONCLUSION: Regional variations in corneal topography and haze can occur within the ablation zone in an individual cornea after photorefractive keratectomy.