Transepithelial photorefractive keratectomy: early clinical results and experience in treating myopic eyes with or without astigmatism

Session Details

Session Title: Surface Ablations for Correction of Ammetropias

Session Date/Time: Tuesday 16/09/2014 | 08:00-10:30

Paper Time: 09:48

Venue: Auditorium

First Author: : S.Mughal UK

Co Author(s): :    V. Patel   A. Hamid           

Abstract Details

Purpose:

To assess the clinical outcomes in terms of the efficacy, safety, and stability of transepithelial photorefractive keratectomy (PRK) using the SCHWIND AMARIS laser platform.

Setting:

Certified and experienced corneal laser surgeons practicing in Optimax Laser Eye Clinics, United Kingdom.

Methods:

In this retrospective analysis, 399 eyes underwent single-step laser epithelial removal and stromal ablation using the transepithelial PRK nomogram of the Amaris laser’s ORK-CAM software (SCHWIND eye-tech-solutions GmbH, Kleinostheim, Germany). All eyes underwent ablation with an Aberration-Free™ algorithm with the SCHWIND AMARIS at a repetition rate of 750 Hz pulse with 1050 Hz eye tracking. The laser ablation was centred on the pupillary axis and static cyclotorsion control program used. The intended refractive aim for all eyes was emmetropia and there were no retreatments included. All eyes had complete pre & postoperative 3 months of visual and refractive data. Uncorrected distance visual acuity (UDVA), manifest refraction and corneal haze were evaluated at 3 months.

Results:

The preoperative manifest spherical equivalent (SE) was -3.88 ± 1.47 dioptres (D) (range: -1.25 to -8.00 D). At 1 month the postoperative manifest SE was reduced to -0.20 ± 0.53 D (range: -4.88 to 1.88) and at 3 months it was -0.17 ± 0.18 D (range: 0.88 to -1.25 D). The manifest SE was within 0.50 D and 1.00 D of emmetropia in 89% and 99% of eyes, respectively. At 3 months, the preoperative manifest sphere was reduced from -3.58 ± 1.44 D (range: -0.50 to -7.75 D) to -0.05 ± 0.33 D (range: +1.25 to -1.00 D) and the preoperative manifest astigmatism was reduced from -0.60 ± 0.53 (range: 0 to -3.50 D) to -0.25 ± 0.25 D (range: 0 to -1.75 D). UDVA of 20/25, 20/20 and 20/16 or better was achieved in 20%, 45% and 24% of 399 eyes, respectively. A gain of 1 or more lines was observed in 25% of eyes. Postoperative corneal haze of ≥1.5 was observed in 2% of eyes.

Conclusions:

Transepithelial PRK for mild to moderate simple myopia or compound myopic astigmatism with SCHWIND AMARIS yields very safe, predictable and satisfactory visual outcomes. Short term follow up also indicates refractive stability and the development of clinically significant corneal haze does not appear to be common but longer term surveillance may be required.

Financial Interest:

NONE