Morphological changes in the cornea of patients with recurrent corneal erosion after diamond burr polishing of Bowman's membrane

Abstract

To evaluate morphological changes in the cornea of patients with recurrent corneal erosion (RCE) using laser confocal microscopy before and after abrasive polishing of Bowman's membrane with a diamond burr (APBMDB). The study included 17 patients (20 eyes) with established RCE diagnosis; they underwent laser confocal microscopy on HRT III device with Rostock Cornea module (Heidelberg Engineering GmbH, Germany). Morphological analysis of epithelial cells, nerve fibers, stroma and corneal endothelium was conducted. After that, all patients underwent APBMDB. Patient examination was repeated after 1, 3, 6, and 12 months. Superficial epithelium was intact before treatment in almost all cases. Islets of hyper-reflective cells, drop-shaped arrangements and stripes characterizing abnormal basal membrane were found in basal epithelium layer. Activated keratocytes and anomalous extracellular matrix were observed in the anterior stroma. No changes could be found in the posterior stroma or endothelium. Subbasal nerve plexus had changes in the form of short and atypically formed corneal nerve fiber funiculi, reduced amount of long corneal nerve fiber funiculi, as well as their tendency for forming closed round shapes. Increase in the amount of Langerhans cells was observed. One month after the procedure, pathological changes in the epithelium and basal membrane were absent, reduction in the amount of Langerhans cells and activated keratocytes was observed. Three months after the polishing, continued reduction of the amount of Langerhans cells was noted. Regeneration of nerves partially restored after 6 months; after 12 months, confocal microscopy results were comparable to healthy volunteers. Confocal laser microscopy of the cornea of patients with RCE showed presence of changes in basal epitheliocytes, basal membrane, anterior stroma and corneal nerve fibers, as well as positive dynamics of these changes after abrasive polishing of Bowman's membrane with a diamond burr.