Posters

15 years follow-up of photorefractive keratectomy up to 10 diopters of myopia and 4.5 diopters of astigmatism

Poster Details

First Author: M.ELBAHRAWY SPAIN

Co Author(s):    F. Soria   P. Peña-Garcia   J. Alio   A. Alessandro     

Abstract Details

Purpose:

To evaluate outcomes of photorefractive keratectomy (PRK) in myopia up to -10.00D and develop a predictive model for the refractive changes in the long-term.

Setting:

Vissum Corporation and Miguel Hernandez University (Alicante, Spain)

Methods:

This retrospective-prospective, observational, consecutive series of cases included 33 eyes of 33 patients aged 46.79±7.04 (range 39 to 54) operated with the VISX 20/20 excimer laser with optical zones of 6mm. The minimum follow up was 15 years. The main outcome measures were: uncorrected and corrected distance visual acuity (UDVA, CDVA), manifest refraction and corneal topography. Linear regression models were developed to predict refractive changes.

Results:

Safety and efficacy indexes at 15 years were 1.18 and 0.83 respectively. No significant differences were detected for any keratometric variable during the follow up (p≥0.103). 15 years after the surgery 54.55% of the eyes were within ±1.00D of spherical equivalent (SE) and 84.85% within ±2.00D. The UDVA at 15 years was 20/30 or better in 60.6% of the eyes and 20/40 or better in 72.73% of the eyes. The correlation between the attempted and the achieved refraction was r=0.948 (p<0.001) at 1 year, and r=0.821 (p<0.001) at 15 years. No corneal ectasia was detected in any case during the follow up.

Conclusions:

PRK is a safe refractive procedure in the long-term within the range of myopia currently considered suitable for its use, although its efficacy decreases with time, especially, in high myopia. The model developed predicts a myopic regression of 2.00 diopters at 15 years for an ablation depth of 130µm. FINANCIAL INTEREST: NONE