One-step transepithelial topography-guided ablation in the treatment of myopic astigmatism.

Aleksandar Stojanovic,Xiangjun Chen,Filip Stojanovic,Ting Zhang,Shihao Chen,Jia Zhang,Tor Paaske Utheim

doi:10.1371/journal.pone.0066618

Abstract

PurposeTo evaluate one-step topography-guided transepithelial ablation in the treatment of low to moderate myopic astigmatism using a 1KHz excimer laser.MethodsRetrospective study of 117 consecutive eyes available for evaluation 12 months after surgery. Pre- and post-operative visual and refractive data as well as post-operative pain and haze were analyzed. A novel technique integrating custom refractive- and epithelial- ablation in a single uninterrupted procedure was used.ResultsThe mean pre-operative spherical equivalent (SE) and the mean cylinder were: –3.22 diopters (D) ±1.54 (SD) (range –0.63 to –7.25 D) and –0.77 D ±0.65 (range 0 to –4.50 D), respectively. At 12 months after surgery: no eyes lost ≥2 lines of corrected distant visual acuity (CDVA). Safety and efficacy indexes were 1.27 and 1.09, respectively. Uncorrected distant visual acuity (UDVA) was ≥20/20 in 96.6% of the eyes. Manifest refraction spherical equivalent was within ±0.5 D of the desired refraction in 93.2% of the eyes. Average root mean square (RMS) wavefront error measured at central 6 mm, increased from 0.38 pre-operatively to 0.47 µm post-operatively. Refractive stability was achieved and sustained 1 month after surgery. No visually significant haze was registered during the observation period. Post-operative pain was reported in 4.5% of patients.ConclusionsOne-step transepithelial topography-guided treatment for low to moderate myopia and astigmatism performed with a 1 KHz laser, provided safe, effective, predictable and stable results with low pain and no visually significant haze.

Highlights

Due to its lower impact on corneal biomechanical stability and lower risk of dry eye[1,2] compared to LASIK, surface ablation is often used in cases with thin corneas, recurrent erosion, predisposition for trauma, or in patients who are anatomically or psychologically unsuitable for use of microkeratome.[3]
Smooth ablation achieved by small-Gaussianbeam, high-frequency lasers, pre-operative use of mitomycin-C, post-operative protection from UV-radiation and dietary supplementation with vitamin-C have previously reduced the incidence and severity of post-operative haze after surface ablation.[11,12,13,14]_ENREF_10 Refinement of de-epithelialization techniques and pre- and post-operative medication continues to decrease the severity of post-operative discomfort[15] and to increase the speed of visual recovery.[16,17]
Has the combination of one-step transepithelial ablation, topographyguided custom ablation and 1000 Hz-laser technology never been published before, but there are few reports concerning any of the mentioned technologies; transepithelial ablation,[21,22,23] topography-guided ablation,[24,25,26,27,28,29,30] or use of 1000 Hz- laser[31,32] in routine treatments of low to moderate myopia in virgin eyes

Summary

Introduction

Due to its lower impact on corneal biomechanical stability and lower risk of dry eye[1,2] compared to LASIK, surface ablation is often used in cases with thin corneas, recurrent erosion, predisposition for trauma, or in patients who are anatomically or psychologically unsuitable for use of microkeratome.[3]. Smooth ablation achieved by small-Gaussianbeam, high-frequency lasers, pre-operative use of mitomycin-C, post-operative protection from UV-radiation and dietary supplementation with vitamin-C have previously reduced the incidence and severity of post-operative haze after surface ablation.[11,12,13,14]_ENREF_10 Refinement of de-epithelialization techniques and pre- and post-operative medication continues to decrease the severity of post-operative discomfort[15] and to increase the speed of visual recovery.[16,17] The current transepithelial topographyguided ablation technique has been reported earlier for treatment of irregular astigmatism.[18,19,20] To our knowledge, has the combination of one-step transepithelial ablation, topographyguided custom ablation and 1000 Hz-laser technology never been published before, but there are few reports concerning any of the mentioned technologies; transepithelial ablation,[21,22,23] topography-guided ablation,[24,25,26,27,28,29,30] or use of 1000 Hz- laser[31,32] in routine treatments of low to moderate myopia in virgin eyes

Methods

Results

Conclusion