Penetrating keratoplasty for keratoconus

We performed a retrospective study of patients with keratoconus who underwent penetrating keratoplasty at the University of California, Davis, during the years 1983-1996 to analyze subsequent visual acuity and the need for optical correction.

We reviewed 123 eyes of 94 patients and collected data including best corrected visual acuity (BCVA) and uncorrected visual acuity (UCVA), type of correction (contact lens vs. spectacles), incidence of rejection, and other complications. Data were obtained at 12 and 18 months postoperatively.

There was a significant improvement of the BCVA between 12 and 18 months (p < 0.05) and no significant improvement in UCVA between at the same times (p = 0.222). At 12 months postoperatively, 84%, and at 18 months, 87% of patients achieved 20/40 or better BCVA. At 18 months, 47% of eyes were fit with contact lenses, and 30%, with spectacles. Mean spherical refraction was -4.13 D +/- 4.41 standard deviation (SD) at 12 months and -4.09 D +/- 3.86 SD at 18 months, whereas mean cylinder was 2.52 D +/- 2.45 SD and 2.67 D +/- 2.04 SD, respectively. Of the eyes, 17.9% had at least one graft rejection, although rejection episodes did not significantly influence the incidence of 20/40 vision (p = 0.084). Combined nonrejection complications did not significantly influence incidence of 20/40 or better vision at 18 months (p > 0.10).

This study reaffirms that the results for keratoplasty in keratoconus are very positive and emphasizes that ophthalmologists should counsel patients about the likelihood of the need for spectacle or contact lens correction. Our data demonstrate that the majority of patients require optical correction for functional visual acuity after keratoplasty.