Visual outcomes of topography-guided excimer laser surgery for treatment of patients with irregular astigmatism

The aim of this study was to evaluate the efficacy, safety, and predictability of topography-guided treatments to enhance refractive status following other corneal surgical procedures. In a prospective case series study, 28 consecutive eyes of 26 patients with irregular astigmatism after radial keratotomy, corneal transplant, small hyperopic and myopic excimer laser optical zones, and corneal scars were operated. Laser-assisted in situ keratomileusis (LASIK) (n = 8) and photorefractive keratectomy (PRK) (n = 20) were performed using the ALLEGRETTO WAVE excimer laser and topography-guided customized ablation treatment software. Preoperative and postoperative uncorrected visual acuity (UCVA), best corrected visual acuity (BCVA), manifest and cycloplegic refraction, and corneal topography with asphericity were analyzed in 12 months follow-up. Uncorrected visual acuity (UCVA) changed from 0.2 +/- 0.2 or (20/100 +/- 20/100) to 0.51 +/- 0.31 or (20/40 +/- 20/60) in the LASIK group (P = 0.01) and from 0.34 +/- 0.16 or (20/60 +/- 20/120) to 0.5 +/- 0.23 or (20/40 +/- 20/80) in the PRK group (P = 0.01). Refractive cylinder decreased from -3.2 +/- 0.84 diopters (D) to -2.06 +/- 0.42 D in the LASIK group (P = 0.07) and from -2.25 +/- 0.39 D to -1.5 +/- 0.23 D in the PRK group (P = 0.008). Best corrected visual acuity did not change significantly in either group. Topography-guided treatment is effective in correcting the irregular astigmatism after refractive surgery. Topography-guided PRK can significantly reduce irregular astigmatism and increase the UCVA and BCVA.