[Long-term results of lasik refractive error correction after penetrating keratoplasty in patients with keratoconus]

Abstract

Objective: To evaluate the long term results of Lasik for residual refractive errors (RE) after penetrating keratoplasty (PKP) for keratoconus (KC).

Design: Retrospective cohort.

Method: Records of 14 consecutive patients (19 eyes) who had Lasik after PKP for KC were retrospectively reviewed. In all eyes with refractive stability and suture removed before Lasik, far distance Visual Acuity with (AVCC) and without correction (AVSC), spherical equivalent (EE), refractive (Ast) and keratometric (dK) astigmatism were analyzed pre- and post-operatively before and after one year of follow up. Data were analyzed using Shapiro-Wilk normality test, Student t test and Mann-Whitney test. A P-value of <0,05 was considered statistically significant.

Results: The mean follow-up time was 3.16 months for the follow-up before one year postoperative and 5.8 years for the follow-up after one year postoperative. The best spectacle corrected visual acuity of 0,11 LogMAR (DE 0,07) before Lasik remained stable throughout the study. The SE decreased from -2.6 (DE 3.53) to -0,36 D (DE 1.33) (P<.05) for the follow-up before one year postoperative and -1.28 D (DE 1.63) (P=.07) for the follow-up after one year postop. The refractive cylinder was reduced from -3.43 (DE 1.35) preoperative to -1.37 D (DE 1.24) (P<.05) and -3.21 D (DE 2.29) (P=.36) in the long term after one year of follow-up.

Conclusions: Lasik refractive results regress one year after the operation; therefore it is not an effective long-term surgical refractive procedure for residual refractive errors after PKP for KC.

Keywords: Astigmatism; Astigmatismo; Error refractivo; Keratoconus; Lasik; Penetrating keratoplasty; Queratocono; Queratoplastía penetrante; Refractive error.