Topography-guided ablation for the treatment of irregular astigmatism

Abstract Purpose Refractive surgery promotes good quality of vision without optical correction in most cases. Conventional ablation has reduced effectiveness in irregular corneas, where custom ablations are usually a better option. We have evaluated the results of visual acuity and refraction in patients undergoing custom topography-guided ablation. Setting Oftalmocentro, Porto Alegre – RS – Brazil. Design This is a case series, retrospective, non-comparative study. Methods We studied 60 eyes from 48 patients who underwent topography guided customized refractive surgery, from October 2013 to September 2017, performed with excimer laser Schwind Amaris 750. Results Mean age was 44.2 years, being most men (56.6%). Patients with penetrating keratoplasty (PKP) encompassed 36.6% (n = 22), previous radial keratotomy (RK) 20.0% (n = 12), previous deep anterior lamellar keratoplasty (DALK) 16.6% (n = 10) and 26.5% (n = 16) with other diagnoses. Topo-guided surgeries were trans-photorefractive keratectomy (trans-PRK) (41.5%), femto laser-assisted in situ keratomileusis (femto-LASIK) (35.0%), laser-assisted in situ keratomileusis (LASIK) (11.6%) and photorefractive keratectomy (PRK) (11.6%). Cylinder refraction decreased from −3.91 D (±2.00) to −1.45 D (±1.43) (p  Conclusion Topography-guided ablation is safe and effective in reducing corneal irregularities, leading to an improvement in visual acuity in 2/3 of cases.