Penetrating Keratoplasty vs. Epikeratoplasty for the Surgical Treatment of Keratoconus

Abstract

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 to limited numbers of cases and follow-up in previous series. All patients who underwent either penetrating keratoplasty or epikeratoplasty 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 visual acuity measured at the time of each follow-up with the presenting optical aid. Inclusion criteria were met for 443 eyes treated with penetrating keratoplasty and 161 eyes treated with epikeratoplasty. Mean follow-up was 4.3 years for penetrating keratoplasty and 4.5 years for epikeratoplasty. In each group, approximately 50% of the patients chose rehabilitation with optical correction with either spectacles or contact lenses and 50% chose no optical correction. Final median logMAR visual acuity for all patients, irrespective of means of visual rehabilitation, was 0.30 (20/40) for penetrating keratoplasty and 0.40 (20/50) for epikeratoplasty (P < .00005). In 209 penetrating keratoplasty and 77 epikeratoplasty eyes with optical correction, the final median logMAR visual acuity was 0.18 (20/30) for penetrating keratoplasty and 0.40 (20/50) for epikeratoplasty (P < .00005). The final median logMAR visual acuity in 234 penetrating keratoplasty and 84 epikeratoplasty eyes without optical correction was 0.48 (20/60) in both groups (P-value was not statistically significant). Although penetrating keratoplasty was statistically superior to epikeratoplasty with respect to visual outcome, results with epikeratoplasty were adequate to recommend its use as a surgical alternative in cases when it is not desirable to perform penetrating keratoplasty.