Ocena zmian krzywizny rogówki występujących po zabiegu fotokeratektomii terapeutycznej (PTK) u pacjentów z nawrotowymi erozjami rogówki
Evaluation of the Corneal Curvature Changes Occurring after Therapeutic Photokeratectomy (PTK) in Patients with Recurrent Corneal Epithelial Erosions
Ewa Mrukwa-Kominek, Elżbieta Magnucka, Stanisława Gierek-Ciaciura, Izabela Zawojska, Rafał Leszczyński
I Katedra i Klinika Okulistyki Śląskiej Akademii Medycznej w Katowicach Kierownik: prof. dr hab. med. Ariadna Gierek-Łapińska
Summary: Purpose: The purpose of the investigation was to evaluate videokeratography-detected alterations to corneal curvature, and refractive changes based on spherical equivalent (EQS). The studied patients underwent phototherapeutic keratectomy (PTK) in central and paracentral cornea for recurrent corneal epithelial erosions. Patients and methods: Post-PTK corneal curvature alterations were analysed in 38 patients with recurrent corneal epithelial erosions. The patients were divided into two groups depending on the method of surgery (central PTK ? group 1, paracentral PTK ? group 2). Corneal curvature alterations were assessed based on videokeratographic values K1 and K2 whereas changes in refraction based on the value of spherical equivalent. Correlations between keratometric changes, and the method and depth of photoablation were analysed. Results: The analysis of K1 and K2 changes revealed significant differences depending on the method of photoablation. Mean post-PTK K1 values were significantly higher than those of K2. Changes in refraction were observed: Group 1: mean post-PTK values of spherical equivalent were higher as compared to those determined prior to PTK; the difference reached the level of statistical significance. Group 2: the difference was not statistically significant. Conclusions: Videokeratography allows accurate visualization of the effect of phototherapeutic keratectomy. PTK for recurrent corneal epithelial erosions, performed according to the method specified in the present paper: ? in central and paracentral erosions ? did not seem to have any effect on corneal curvature and hence also not on refraction changes; ? central photoablation only resulted in insignificant corneal curvature alterations, which did not cause refraction changes.
Keywords: phototherapeutic keratektomy, recurrent erosion, keratometry, changes in refraction