A Novel Approach to Enhancement Linked Laser Asymmetric Keratectomy Using Semi-Cylindrical Ablation Pattern in Patients with Myopic Regression After Laser Refractive Surgery

A Novel Corneal Remodeling Technique of Laser Asymmetric Keratectomy in Keratoconus Suspect: A Retrospective Case Control Study

Purpose

This retrospective case control study report includes 4 eyes of 4 patients (aged from 37 to 44 years) with keratoconus suspect (KCS) who underwent laser epithelial keratomileusis linked laser asymmetric keratectomy (L-LAK) as corneal remodeling technique in order to avoid postoperative corneal ectasia.

Patients and Methods

Four eyes of 4 patients showed corneal topography findings with abnormal localized steep keratometric curvature greater than 47.0 D and peripheral corneal thickness asymmetry (Total corneal central thickness deviations in four directions on Orbscan map (SUM)≥80 µm). L-LAK could be performed both the original ablation of refractive errors (SE from -1.25 to -5.50 D) and the customized ablation (selective ablation of the thicker peripheral cornea averaging:64 µm selectively and the central cornea of the myopic shift due to LAK averaging-1.50D. The main outcome measures between preoperative and postoperative 2 year were refraction, visual acuity (UDVA), keratometry, corneal symmetry evaluating SUM.

Results

After 2 years, SEs (D, average) were -0.34, UDVA (LogMAR) was 0.00. keratometry including Kmax was markedly decreased, SUM had diminished markedly. There were no case of postoperative adverse effects.

Conclusion

L-LAK resulted in a decreased SUM, increased corneal symmetry, and no postoperative corneal ectasia with good visual outcomes in myopic patients with KCS.

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

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.