Laser in situ keratomileusis for ametropia after penetrating keratoplasty

PURPOSE: To evaluate the efficacy of excimer laser in situ keratomileusis ( LASIK) in the treatment of refractive errors after penetrating keratoplasty . METHODS: Eight eyes underwent LASIK after a mean 71 months (SD 60) followin g the initial penetrating keratoplasty, A full ophthalmic assessment was pe rformed before LASIK and at 1 week, 1, 3, 6, and 12 months after surgery. M ean follow-up was 8.6 months (SD 3.2). RESULTS: No eyes lost any Snellen lines of best spectacle-corrected visual acuity at the latest follow-up. Mean reduction in spherical equivalent refr action was 91% from -6.79 D (SD 4.17) to -0.64 D (SD 1.92) and mean reducti on of cylinder was 72% from -6.79 D (SD 3.28) to -1.93 D (SD 1.17) at 6 mon ths. Mean surgically induced astigmatism was 5.50 D (SD 2.42) and the index of surgically induced astigmatism divided by the initial cylinder expresse d as a percentage was 81%. Mean outcome indices were: correction index 0.87 , index of success 0.31, and angle of error 0.95 degrees, Three eyes (43%) achieved a spherical equivalent refraction of +/-0.50 D and 4 eyes (57%) ac hieved a spherical equivalent refraction of +/-1.00 D of emmetropia. CONCLUSIONS: The efficacy of LASIK after penetrating keratoplasty was good compared to incisional or surface based excimer laser methods and has the a dvantage of reducing the myopic spherical equivalent refraction in addition to astigmatism, thus improving the uncorrected visual acuities.