Sequential Customized Phototherapeutic Keratectomy After Meniscus-shaped Stromal Lenticule Addition Keratoplasty in...

To assess the safety and effectiveness of sequential customized transepithelial phototherapeutic keratectomy (SCTK) performed after meniscus-shaped stromal lenticule addition keratoplasty (MS-SLAK) in patients with advanced keratoconus, with a focus on higher order aberrations (HOAs), corrected distance visual acuity (CDVA), and corneal biomechanics.

This prospective interventional study included patients previously treated with MS-SLAK for advanced keratoconus, showing corneal HOAs 3 μm or greater at a 4-mm pupil diameter and at least 200 μm of stromal thickness anterior to the implanted lenticule. All patients underwent SCTK using excimer laser ablation based on the corneal aberrometer, treating HOAs. Two sequential customized SCTK ablations were performed with intraoperative topographic reassessment. Patients were evaluated at baseline and at 3, 6, and 12 months postoperatively. Parameters included CDVA, manifest refraction spherical equivalent, corneal and ocular wavefront, tomographic data, and dynamic corneal response measurements.

Six eyes from six patients were analyzed. The procedure resulted in significant visual improvement, with median spectacle CDVA improving from 20/125 to 20/32 at 12 months (P = .0001), and median contact lens CDVA reaching 20/25. HOAs significantly decreased, particularly root mean square (RMS) coma (from 3.3 (1.6) to 1.0 (0.5) μm, P = .02) and ocular RMS HOA (from 4.1 (1.8) to 1.8 (0.4) μm, P = .03). Corneal biomechanics remained stable throughout follow-up, with no signs of ectasia.

SCTK following MS-SLAK seems an effective sequential treatment strategy in advanced keratoconus. Combining biomechanical reinforcement with optical surface regularization enhances visual function and reduces HOAs, and could offer a viable alternative to corneal transplantation in selected cases.