Abstract
Purpose: :
To evaluate the changes on visual acuity of patients with corneal transplants (PKP), who undergone photorefractive keratectomy (PRK) based on topography (Topolink) with mitomycin C (MMC).
Methods: :
This is a case series study of 12 ammetropic patients (-8.75 to 3.25D) with penetrating corneal transplant due to keratoconus (9), corneal dystrophy (2) and leukoma (1) with astigmatism (-7.75 to -4.25 D) who undergone PRK with MMC. The corneal topography of all patients was measured using a Pentacam (Oculus, Germany), a Shack-Hartmann type wavefront analyzer (Schwind Ocular Wavefront Analyzer) and Placido-based topography (Corneal Wavefront Analyzer, Schwind eye-tech-solutions GmbH, Germany), pre-operatively and 6 months post-operatively.
Results: :
Six months after topography assisted PRK with MMC, best spectacle corrected visual acuity (BSCVA) of 20/20 or better was achieved on 45.55% of the eyes, compared to 10 % of the eyes before the surgery (p=0.0893, Χ2 test). At this period, only one patient had lost of lines of BSCVA 20/20 to 20/50, while one line or more of BSCVA were gained in all of the others (p=0.00814; Student paired t test). There was significant reduction of astigmatism (-5.52±1.28D) compared to pre operative (-3.00±1.64D) (mean, t test p=0.0004). Central corneal thickness also was significantly reduced 6 months post Topolink (mean, t test p=0.001).
Conclusions: :
6 months post surgery BSCVA improved significantly, there was gain of lines and reduction of astigmatism and corneal thickness. Photorefractive keratectomy (PRK) with topography based (Topolink) with MMC might be a better alternative for correction of irregular astigmatism post PKP.
Keywords: transplantation • astigmatism • refractive surgery: PRK