Abstract
Purpose: :
To evaluate the efficacy, predictability, stability and safety of photorefractive keratectomy (PRK) with mitomycin C (MMC) in patients with anisometropia after keratoplasty.
Methods: :
A retrospective review was done of all cases of PRK performed with the VISX Star S4 excimer laser with mitomycin C between January 1, 2004 and December 31, 2008 for post-keratoplasty anisometropia. The main outcome measure was best spectacle corrected distance visual acuity (CDVA) and patient tolerance of the full spectacle refractive correction. Secondary outcome measures were uncorrected distance visual acuity (UDVA), refractive accuracy and stability, and complications.
Results: :
Twenty cases met the inclusion criteria. At 6 months, the spectacle CDVA had improved from a preoperative mean of 20/49 to 20/30 (P = 0.01). Seven (35%) eyes gained 3 or more lines of CDVA. The spherical equivalent anisometropia decreased from a preoperative mean of 3.79D to 0.59D (P < .001). All 20 (100%) patients were subjectively satisfied with full binocular spectacle correction. There was an improvement in UDVA from a preoperative mean of 20/282 to 20/55. There was a reduction in the mean spherical equivalent from -5.2 diopters (D) to -0.8D, in myopia from -7.6D to -1.8D, and in refractive astigmatism from 4.9D to 2.0D. There was no significant change in visual acuity or spherical refractive error between 3 and 12 months. No sight threatening complications occurred in any eye. One (5%) eye lost 2 lines of CDVA.
Conclusions: :
Photorefractive keratectomy with MMC a safe and effective method of reducing post-keratoplasty anisometropia and providing spectacle rehabilitation.
Keywords: refractive surgery: PRK • transplantation • astigmatism