Transepithelial topography and OCT-guided custom ablation for enhancement of regression after myopic refractive surgery

Session Details

Session Title: Advanced Surface Photoablation I

Session Date/Time: Sunday 08/10/2017 | 08:00-09:30

Paper Time: 08:30

Venue: Meeting Center Room I

First Author: : W.Zhou NORWAY

Co Author(s): :                        

Abstract Details

Purpose:

To evaluate the outcomes of transepithelial surface ablation retreatments guided by cornea topography and optical coherence tomography (OCT), in corneas with regression after previous myopic laser refractive surgery. The use of data generated by corneal topography and corneal OCT were aimed to address the issues caused by secondary corneal irregularities and epithelial remodeling after previous surgery.

Setting:

Noncomparative interventional case series from SynsLaser clinic in Tromsø, Norway.

Methods:

A retrospective consecutive case series of 50 eyes of 38 patients with regression after previous corneal refractive surgery for treatment of myopia and compound myopic astigmatism underwent transepithelial topography- and OCT-guided enhancements. Ablation profile was based upon data from corneal topography, while the epithelial ablation depth was decided by corneal epithelial mapping obtained by OCT. The study assessed preoperative and postoperative results regarding uncorrected distance visual acuity (UDVA), manifest refraction and corrected distance visual acuity (CDVA), topographic anterior corneal irregularity index (IRI), asphericity, odd-order and even-order higher order aberrations (HOAs) as well as epithelial thickness profile.

Results:

The mean follow-up time after retreatment was 15.3 ±10.3 months. The mean spherical equivalent (SE) was reduced from -1.04 diopters (D) ±0.55 (SD) to -0.26D±0.45. Safety and efficacy indexes were 1.07 and 0.88 respectively. At their last follow-up visit 96% and 63% had a UDVA of 20/40 and 20/20 or better. IRI and odd-order HOAs both improved significantly (p<0.001 and 0.03), while even-order HOAs and total corneal asphericity did not improve significantly (p=0.15 and 0.55). Epithelial thickness profile showed significant smoothening between the central 2mm and 2-5mm with an average decrease in difference of 3.86 µm (p<0.001).

Conclusions:

Transepithelial, topography-and OCT-guided custom retreatment is safe and highly effective for regression in patients who previously underwent myopic refractive surgery.

Financial Disclosure:

NONE