Topographically guided two-step LASIK and standard LASIK in the correction of refractive errors after penetrating keratoplasty

PURPOSE: To evaluate in a long-term period the effectiveness and safety of topographically guided two-step laser in situ keratomileusis (LASIK) and standard LASIK technique in the correction of refractive errors after successful penetrating keratoplasty (PKP) for keratoconus. METHODS: At least 2 years after PKP and 6 months after removal of all sutures, 15 eyes of 15 patients (Group 1; mean manifest refraction spherical equivalent (MRSE) -7.23 D -/+ 3.42 SD) were submitted to standard LASIK and 15 eyes of 15 patients (Group 2; mean MRSE -4.37 D -/+ 1.97 SD) to a topographically guided two-step LASIK procedure (first the flap and at least 2 weeks later the laser ablation). In all cases, a superior hinged corneal flap(160 microm/9.5 mm) was created. RESULTS: After a follow-up of 36 months, in Group 1 the mean uncorrected visual acuity (UCVA) was 0.51 logarithm of the minimum angle of resolution (logMAR) -/+ 0.41 SD and the mean best-corrected visual acuity (BCVA) was 0.03 logMAR -/+ 0.05 SD, with a mean MRSE of -1.57 D -/+ 2.65 SD. In Group 2, the mean UCVA was 0.28 logMAR -/+ 0.24 SD and the mean BCVA was 0.01 logMAR -/+ 0.03 SD, with a mean MRSE of -0.07 D -/+ 1.00 SD. In both groups, no complications were observed. CONCLUSIONS: After a long follow-up period, both topographically guided two-step LASIK and standard LASIK could be considered effective and safe tools in the correction of refractive errors after successful PKP for keratoconus.