Posters

Topography-guided photorefractive keratectomy for post-keratoplasty astigmatism: long-term outcomes

Poster Details

First Author: M.Bizrah UK

Co Author(s):    D. Lin   A. Babili   M. Wirth   S. Arba-Mosquera   S. Holland        

Abstract Details

Purpose:

To evaluate the long-term efficacy and safety of topography-guided photorefractive keratectomy (TG-PRK) for post-keratoplasty refractive error correction.

Setting:

This study was carried out at the Pacific Laser Centre in Vancouver, British Columbia, Canada. The study was granted ethical approval by the Pacific Laser Centre ethical review board, and was conducted in adherence with the principles of the Declaration of Helsinki.

Methods:

A retrospective interventional case series of 54 eyes of 50 patients who underwent previous cornea transplants. Unaided (UDVA) and best-corrected (CDVA) distance visual acuities, manifest refraction, mean central keratometric value, mean keratometric astigmatism, and post-operative complications were reviewed.

Results:

Mean final follow-up was 31 months. 16.7% of eyes underwent >1 surface ablation. Mean UDVA improved from 0.96 logMAR pre-operatively to 0.46 logMAR at final follow-up (Bonferroni, p<0.0001). Mean UDVA improved by 4.4 Snellen lines. CDVA improvement was not significant. Mean astigmatism improved from -4.4D pre-operatively to -2.4D at final follow-up (Bonferroni, p<0.0001). 9% at pre-operative visit and 55% at final visit had less than 2D of astigmatism, respectively. Keratometric astigmatism decreased from 5.24D pre-operatively to 2.98D at final follow-up (t-test, p<0.0001). No eyes developed clinically-significant haze, 14.8% developed regression and 13% had a reduction ≥2 CDVA .

Conclusions:

In conclusion, this is the largest study to date of TG-PRK for post-keratoplasty refractive error, and has the longest follow-up results. In line with previous studies, our study gives strong evidence for the role of TG-PRK in improving refraction, topographic keratometry measurements and visual acuity. An important finding in this paper is that most eyes do not required more than one TG-PRK treatment. Also, regression observed after 1st year of treatment means that future studies on refractive laser correction post-keratoplasty should ideally have a minimum of 2-3 years of follow-up.

Financial Disclosure:

is employed by a for-profit company with an interest in the subject of the presentation, receives consulting fees, retainer, or contract payments from a competing company