Trans Photorefractive Keratectomy To Treat High Order Aberrations In Stable Keratoconus Having The Ablation Decentration In Coma Axis.

To describe the visual and aberrometric outcomes after trans photorefractive keratectomy (PRK) to treat high order aberrations (HOAs) in stable KC in which decentration of the ablation was performed towards the axis of the coma

Research Department at Ofttalmosalud, Instituto de Ojos, Lima, Peru

Prospective case series study conducted between October and March 2020. The patients underwent trans-PRK technique to treat HOAs without correction of the sphero-cylindrical component with decentration of the ablation in the coma's axis. Visual acuity, refraction, and aberrations were assessed preoperatively and postoperatively at 1, 3, and 6 months. Patients with stable keratoconus from stages I to III (Amsler-Krumeich) are included. minimum pachymetry 430 µm, corrected distance visual acuity (CDVA) and high-order aberrations greater than 1,00 µm. Trans-PRK was performed using the Amaris 1050, with a maximum consumption at the cone apex of 100 µm. In all cases, decentration of the ablation was performed towards the axis of the coma.

The study included 25 eyes of 20 patients. CDVA improved from 0.21 ± 0.05 LogMAR preoperative to 0.08 ± 0.04 LogMAR at 6 months postoperative (p=0.03). Corneal high order aberrations decreased from 2.67 ± 1.06 µm at preoperative evaluation to 2.11 ± 0.65 µm at 6 months (p=0.001); coma decreased from 2.17 ± 1.07 µm to 1.75 ± 0.63 (p=0.001). No patient presented a loss of CDVA lines. No patient has shown signs of corneal ectasia.

 Trans-PRK is effective and safe to correct high-order aberrations in patients with stable keratoconus, improving CDVA.