Optical Coherence Tomography versus Ultrasound Biomicroscopy Imaging of the Anterior Segment in Diagnosing Acute Keratoconus: A Comparative Analysis

Abstract

Objective To compare and analyze the differences between anterior segment optical coherence tomography (AS-OCT) and ultrasound biomicroscopy (UBM) in imaging acute keratoconus. Method The features of AS-OCT and UBM images of acute keratoconus patients in Hebei Eye Hospital were analyzed retrospectively. Result From May 2016 to September 2021, 43 patients (43 eyes) with acute keratoconus were treated at Hebei Eye Hospital. Both AS-OCT and UBM images showed a ruptured Descemet’s membrane, edema, thickening of the stromal layer, and fissures forming in it to connect to the anterior chamber. AS-OCT images showed an intact corneal epithelium, with 29 cases presenting with epithelial edema formation. UBM images showed Descemet’s membrane detachment with a break in 28 cases. Pearson correlation analysis showed a significant correlation between the Descemet’s membrane rupture size and rupture height (r = 0.763, P < 0.001) but no correlation between rupture size and rupture with delamination of collagen lamellae (r = 0.090, P > 0.05). No corneal perforation was found in the 43 eyes. In the healing stage after deep lamellar keratoplasty, there was significant stromal scarring with a pan-stromal scar, significant stromal thickening, and cornea flattening. Conclusion AS-OCT and UBM can complement each other in providing accurate corneal images and parameter measurements for predicting and evaluating disease progression.