Clinical Outcomes of Laser Asymmetric Keratectomy to Manage Postoperative Adverse Effects–A Retrospective Clinical Trial

Abstract

Background: Laser asymmetric keratectomy reduces the regional asymmetry of corneal thickness. Objective: We aimed to describe the clinical outcomes of laser asymmetric keratectomy keratectomy with laser refractive surgery performed to resolve the adverse effects following ophthalmic surgeries. Methods: We compared the preoperative and postoperative outcomes and complaints of blurring after performing laser asymmetric keratectomy with laser refractive surgery in 24 eyes of 16 patients with a deviation sum in corneal thickness in four directions >80 µm. Laser asymmetric keratectomy with laser refractive surgery, with full integration of the Vision Up software, was used to analyze the corneal thickness deviation, employed selective laser ablation to create central symmetry on the thicker cornea to reduce regional asymmetry of corneal thickness, simultaneously correcting the refractive power and myopic shift. The pre-and postoperative clinical and topographic findings were analyzed. Results: The patients’ age was 37.57±22.30 (range, 23–65) years. The follow-up period was 16.56±3.23 months. The spherical equivalent (p=0.026), sphere (p=0.022), uncorrected distance visual acuity (LogMAR, p=0.045), blurring score (p=0.000), central corneal thickness (p=0.024), sum of deviations in corneal thickness in four directions (p=0.02), distance between the maximum posterior elevation and visual axis (p=0.04), and kappa angle (p=0.031), significantly decreased postoperatively. The efficiency and safety indices were 0.96±0.11 and 1.00, respectively. There was no myopic regression or blurred vision postoperatively. Conclusion: Performing laser asymmetric keratectomy with laser refractive surgery improved corneal symmetry and visual acuity and reduced blurring.

Laser Refractive Surgery (LRS) with Laser Asymmetric Keratectomy (Crescentic LRS) to Avoid LRS Adverse Effects

“…Deviations in corneal thickness is a major factor in causing LRS adverse effects [5][6][7][8][9][10]. The sum of corneal central thickness deviations in four directions on Orbscan map (SUM) as a new evaluation index of corneal asymmetry was reported [7][8][9][10][11][12][13][14][15]. Recently, laser asymmetric keratectomy (LAK) has been reported, which is a biomechanical customized asymmetric corneal ablation method with full integration of Vision Up software and applied to avoid LRS adverse effects [7][8][9][10], a novel approach to enhancement in patients with myopic regression after LRS [11][12][13] and a new corneal remodeling technique in keratoconus suspect without postoperative corneal ectasia [14,15].…”

“…The sum of corneal central thickness deviations in four directions on Orbscan map (SUM) as a new evaluation index of corneal asymmetry was reported [7][8][9][10][11][12][13][14][15]. Recently, laser asymmetric keratectomy (LAK) has been reported, which is a biomechanical customized asymmetric corneal ablation method with full integration of Vision Up software and applied to avoid LRS adverse effects [7][8][9][10], a novel approach to enhancement in patients with myopic regression after LRS [11][12][13] and a new corneal remodeling technique in keratoconus suspect without postoperative corneal ectasia [14,15]. LRS combined with LAK (that is, so called as crescentic LASEK or LASIK) corrected refractive power and ablate on the thick peripheral cornea with integration of Vision UP software® to make cornea to be symmetric and ablate induced myopia due to LAK simultaneously.…”