Diagnostics
Intraoperative OCT-Based Stromal Topography in Phototherapeutic Keratectomy
By Vitus Grauvogl, Stefan A. Kassumeh, Wolfgang Johann Mayer and 5 others.
Abstract
Objectives
This study aims to investigate whether anterior corneal curvature can be reliably measured by combined Placido–optical coherence tomography (OCT) during phototherapeutic keratectomy (PTK) despite intraoperative stromal swelling, and to quantify the immediate smoothing effect of PTK on anterior stromal higher-order aberrations (HOAs).
Methods
In this prospective study, 20 eyes with epithelial basement membrane dystrophy (EBMD) undergoing PTK were examined using the MS-39ã (CSOã) at four timepoints: preoperatively (t1), after epithelial debridement (t2), after PTK ablation (t3), and at 3-month follow-up (t4). Anterior curvature, corneal and stromal thickness, and epithelial thickness were analyzed across 17 corneal sectors within an 8 mm zone using two-way repeated-measures analysis of variance (ANOVA) (timepoint × sector). Anterior Zernike HOAs were computed globally, and the smoothing effect of PTK ablation was assessed by paired comparison of t2 and t3, both obtained on de-epithelialized stroma.
