Objective: To evaluate the safety and efficacy of excimer laser refractive
surgery in correcting refractive error in eyes that have undergone previous
penetrating keratoplasty (PK).
Methods: Twenty-three keratorefractive procedures on 16 eyes from 16
consecutive subjects were evaluated between 2002 and 2008. Each patient
presented a previous history of a PK with subsequent postoperative myopia
and astigmatism. Keratometric value, manifest refraction, best-corrected visual
acuity, uncorrected visual acuity, and complications were determined.
Results: There were a total of 14 photorefractive keratectomy (PRK)
procedures performed on 11 eyes and 9 laser in situ keratomileusis
(LASIK) procedures performed on 5 eyes. In the PRK group, the preoperative
post-PK manifest refractive spherical equivalent and cylindrical
error were 6.22 6.23 diopter and 5.23 2.26 D, respectively. The
PRK postoperative manifest refractive spherical equivalent and cylindrical
error were 3.61 4.23 D (P0.25) and 3.21 1.78 D (P0.02),
respectively. In the LASIK group, the preoperative post-PK manifest
refractive spherical equivalent and cylindrical error were 3.05 3.29 D
and 4.11 2.38 D, respectively. The LASIK postoperative manifest
refractive spherical equivalent and cylindrical error were 1.51 2.02 D
(P0.24) and 2.08 1.26 D (P0.03), respectively. There was a 2-line or
greater improvement of uncorrected visual acuity in 8 of the 14 PRK treatments
and 5 of the 9 LASIK treatments. There were two episodes of acute graft
rejection. One of the episodes resolved with topical and oral corticosteroids,
and the other episode required a repeat corneal transplantation.
Conclusions: PRK and LASIK are effective tools in reducing surgically
induced astigmatism after penetrating corneal transplantation in most
patients in this case series. The reduction of astigmatism may allow
improved contact lens or spectacle fitting to achieve best-corrected binocular
visual acuity.