A Novel Corneal Remodeling Technique for the Management of Keratoconus

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.

Femtosecond laser-assisted implantation of corneal stroma lenticule for keratoconus

Purpose

To review recent progress, challenges, and future perspectives of stromal keratophakia for the treatment of advanced keratoconus.

Methods

We systematically reviewed the literature in the PubMed database, last update June 30, 2020. No language restriction was applied. The authors checked the reference lists of the retrieved articles to identify any additional study of interest.

Results

Several techniques have been proposed for the treatment of keratoconus in order to avoid or delay keratoplasty. This was primarily due to the lack of accessibility to donor corneas in many countries. The ease and predictability of the more advanced femtosecond lasers used to correct ametropias by stromal lenticule extraction lead to hypothesize that generated refractive lenticules could be implanted into corneal stromal layers to restore volume and alter the refractive properties of the cornea in patients with corneal ectasias. At the same time, new techniques for preservation, customization, and cellular therapy of the corneal stromal have been developed, directing to the valorization of otherwise discarded byproducts such as donor corneas unsuitable for either lamellar of penetrating keratoplasty.

Conclusions

Femtosecond laser-assisted stromal keratophakia could be a suitable therapeutic option for the treatment of corneal ectasias, especially in patients with advanced keratoconus, providing biomechanical support recovering the pachimetry to nearly normal value at the same time. The accuracy and predictability of the refractive outcome are yet a critical issue and the patient eligible for the procedure still has to be characterized.

Long-term Outcomes of a New Surgical Technique for Corneal Remodeling in Corneal Ectasia

PURPOSE

To analyze the outcomes of a new technique (corneal remodeling) to treat corneal ectasia.

METHODS

Sixty-nine cases that underwent corneal remodeling were analyzed. Anesthetic drops were instilled and a femtosecond laser platform was used to perform an 8-mm diameter keratectomy (180°, 270°, or 360°). Once ablation was completed, the edges of the resection were sutured with 8 to 12 interrupted stitches.

RESULTS

Three-year follow-up data are presented. The age of the population was 30.83 ± 12.65 years (range: 16 to 48 years). At 36 months postoperatively, 57.2% presented with uncorrected distance visual acuity (UDVA) of 20/100 or worse and 42.8% achieved between 20/80 and 20/40. After performing photorefractive keratectomy in 3 cases, 14.3% presented with UDVA of 20/100 or worse, 57.2% achieved between 20/80 and 20/40, and 28.5% achieved 20/30 or better in 180° arc length keratectomy. Most parameters compared were moderately to statistically significant (P < .05 to < .0000001).

CONCLUSIONS

Corneal remodeling is a safe technique that produces corneal flattening, reduction of anterior chamber depth, and decreased optical aberrations. It also offers a possibility to perform complementary refractive procedures. [J Refract Surg. 2019;35(4):261-267.].