Visual Outcomes and Aberrometric Changes With Topography-Guided Photorefractive Keratectomy Treatment of Irregular Astigmatism After Penetrating Keratoplasty.

Abstract

To evaluate the visual acuity and keratometric and aberrometric changes in patients with corneal transplants (PKP), who underwent topography-guided photorefractive keratectomy (TG-PRK) with mitomycin C (MMC). In this case study, 15 patients with spherical equivalents ranging from -11.00 to -0.25 diopters (D) who underwent penetrating corneal transplantation and had irregular astigmatism ranging from -7.5 to -2.0 D underwent TG-PRK with MMC. Corneal topography and wavefront of all patients were measured preoperatively and 12 months postoperatively. Twelve months after TG-PRK with MMC, 46% of eyes achieved a best spectacle-corrected visual acuity (BSCVA) of 20/20 compared with 1 eye preoperatively (P = 0.0221, χ test). The BSCVA did not improve in 1 patient and increased by 1 line or more in all others. Astigmatism decreased significantly (P = 0.003) from 5.10 ± 0.4 D to 3.37 ± 0.06 D, the corneal best-fit sphere increased and keratometry measurements flattened significantly (P = 0.0001 for both comparisons), and the corneal total root mean square aberrations and trefoil decreased significantly (P = 0.0077 and P = 0.0054, respectively) from 9.11 ± 2.56 μm to 7.58 ± 3.15 μm and 2.00 ± 1.2 to 1.38 ± 0.27 μm, respectively, as measured by wavefront aberrometry. Twelve months postoperatively, the BSCVA improved significantly, the lines of vision increased, and astigmatism, corneal best-fit sphere, mean keratometry, corneal thickness, corneal root mean square total, and corneal spherical aberrations decreased. TG-PRK with MMC is a good alternative for correcting post-PKP cases with irregular astigmatism with elevated higher-order aberrations.