Back to Freepaper Session

Eighteen year follow-up of excimer laser photorefractive keratectomy (PRK) with 6.00mm optical zone

Session Details

Session Title: Surface Ablation I

Session Date/Time: Sunday 06/10/2013 | 08:00-09:30

Paper Time: 08:06

Venue: Main Lecture Hall (Ground Floor)

First Author: : Z.Shalchi UK

Co Author(s): :    D. O"Brart   P. Patel   R. McDonald   J. Marshall     

Abstract Details

Purpose:

To evaluate the long-term refractive and topographic stability of excimer laser photorefractive keratectomy (PRK) with 6.00mm optical zone surgery.

Setting:

St Thomas’ Hospital, London, United Kingdom

Methods:

Forty four patients underwent clinical assessment 18 years after myopic PRK with 6.00mm optical zone as part of a number of randomized controlled clinical trials. Only one eye per patient was selected for analysis. The pre-operative mean spherical equivalent (MSE) refractive error was -4.80D (range -2.75 to -7.38D) with mean programmed correction -4.37D (range -2.50 to -7.00D).

Results:

At 18 years, the MSE refraction was -0.74D (range -4.63 to +1.50D), with 25% of eyes within 0.5D and 54% within 1.0D of intended correction. There was no difference in MSE between 1 and 18 years (p=0.06). However, patients aged 60 years or younger at 18 year review (n=22) showed mild myopic regression (-0.62D, p<0.01) which was not true for those aged over 60 (n=22) (+0.03D, p=1.00). The efficacy index was 0.65 and safety index 1.01. 95% of corneas were clear, with 2 showing only trace haze. There was no evidence of ectasia on Scheimpflug topographic examination.

Conclusions:

Excimer laser PRK shows refractive stability between 1 and 18 years. There is mild myopic regression in younger patients. The procedure is safe with no long-term sight-threatening complications.

Financial Interest:

NONE