Objective: To determine the long-term effect on vision of penetrating keratoplasty performed for keratoconus.
Design: Retrospective noncomparative case series.
Participants: All patients with keratoconus who received a corneal graft and who remained in our center for follow-up and visual rehabilitation during the study period.
Intervention: Penetrating keratoplasty was performed in 93 eyes of 78 patients.
Main outcome measures: Graft survival, visual acuity, and astigmatism.
Results: One (1.08%) graft failure was encountered over a mean follow-up of 46 months. Mean preoperative (best corrected) and postoperative visual acuity is (best-tolerated correction) were 0.9 (20/160) and 0.24 (20/80) logMAR, respectively. Visual acuity in 86% of eyes was 0.3 logMAR (20/40) or better at the latest follow-up, with 67% of eyes being corrected with spectacles. Mean preoperative corneal power by keratometry was more than 52 diopters (D) in 83% of eyes; mean postoperative corneal power was 45 +/- 2 D. No significant predictors of postgraft astigmatism were found. Mean preoperative and postoperative best-eye acuities of the better eye were 0.32 (20/40-1) and 0.18 (20/32+1) logMAR, respectively (P < 0.001).
Conclusions: Graft survival was excellent. A corrected visual acuity of 20/40 or better was obtained in 86% of eyes. Astigmatism could not be predicted from preoperative factors. Visual acuity measured in the better eye improved by 0.14 logMAR (1.4 lines), implying an overall functional gain for the patient.