Visual improvement as a function of time after lamellar keratoplasty for keratoconus

Twenty-eight keratoconic patients with either contact-lens intolerance or marked corneal scarring over the visual axis underwent lamellar keratoplasty for visual rehabilitation. All 28 patients returned for follow-up at six months, 27 (98%) had follow-up at one year, and 23 (82%) at two years. The 23 patients with two-year follow-up showed progressive improvement of visual acuity over time. At six months, 11 of 23 patients (48%) had visual acuity of 20/30 or better. At one year, 17 of 23 (74%) had 20/30 or better, and at two years, 21 of 23 (91%) had 20/30 or better. The average postoperative keratometry measurement at two years was 43.5 diopters (S.D. = 2.5 diopters), which represented an average reduction of 13 diopters from preoperative keratometry. All patients who were less than 32 years old obtained visual acuity of 20/30 or better after two years and reached this level significantly (F = 6.75, P = .02) sooner than those more than 32 years old. These results compare favorably with previously reported visual results after penetrating keratoplasty.