Penetrating keratoplasty vs. epikeratoplasty for the surgical treatment ofkeratoconus

PURPOSE: Penetrating keratoplasty and epikeratoplasty have been utilized in the surgical treatment of keratoconus. Comparison of the relative efficacy of each procedure in achieving visual outcomes has not been achieved due t o limited numbers of cases and follow-up in previous series. METHODS: All patients who underwent either penetrating keratoplasty or epik eratoplasty for keratoconus between January 1987 and December 1997, and for whom at least 24 months of postoperative follow-up data for visual acuity was documented in the medical record, were included in this retrospective, nonrandomized, sequential comparative trial. The sole criteria for outcome in each group, as well as for comparison of the two groups, was Snellen vis ual acuity measured at the time of each follow-up with the presenting optic al aid. RESULTS: Inclusion criteria mere met for 443 eyes treated with penetrating keratoplasty and 161 eyes treated with epikeratoplasty. Mean followup was 4 .3 years for penetrating keratoplasty and 4.5 years for epikeratoplasty. In each group, approximately 50% of the patients chose rehabilitation with op tical correction with either spectacles or contact lenses and 50% chose no optical correction. Final median logMAR visual acuity for all patients, irr espective of means of visual rehabilitation, was 0.30 (20/40) for penetrati ng keratoplasty and 0.40 (20/50) for epikeratoplasty (P < .00005). In 209 p enetrating keratoplasty and 77 epikeratoplasty eyes with optical correction , the final median logMAR visual acuity was 0.18 (20/30) for penetrating ke ratoplasty and 0.40 (20/50) for epikeratoplasty (P < .00005). The final med ian logMAR visual acuity in 234 penetrating keratoplasty and 84 epikeratopl asty eyes without optical correction was 0.48 (20/60) in both groups (P-val ue was not statistically significant). CONCLUSIONS: Although penetrating keratoplasty was statistically superior t o epikeratoplasty with respect to visual outcome, results with epikeratopla sty were adequate to recommend its use as a surgical alternative in cases w hen it is not desirable to perform penetrating keratoplasty.