In vivo confocal microscopy of abnormal cornea: a clinical and pathological correlation

Abstract

Abstract Purpose To establish correlations between in vivo confocal microscopic (IVCM) images with histopathology of various ocular surface disorders. Methods 50 patients with various ocular surface/corneal diseases scheduled to undergo biopsy, impression cytology or surgery such as keratoplasty were clinically examined and assessed by IVCM with emphasis on area of pathology. The tissue obtained was then oriented and studied by light and/or electron microscopy. The microscopic anatomy was then correlated with the IVCM findings to establish a pathological basis for the observations. Conditions studied included corneal degenerations & dystrophies, conjunctival tumours, conjunctivalisation of the cornea and others. The Rostock Cornea Module (RCM) attached to HRT II machine from Heidelberg Engineering was used for IVCM. Results By precise histological characterization of tissue changes we have been able to assign diagnostic criteria to IVCM features such as hyper and hypo reflective dots and shapes, linear straight and branching images and smaller dendritic figures. A diagnostic feature of intraepithelial neoplasia by IVCM has been established. A distinct pre Descemet’s layer, termed the posterior stromal layer has also been defined. Subepithelial bright shadows in advanced Fuch’s endothelial dystrophy have been identified as fibroblasts. Other interesting correlations are emerging. Conclusion High quality in vivo corneal confocal microscopic imaging can highlight pathological changes comparable to those found in histopathology slides in a way that can help establishing diagnostic confocal microscopic criteria obviating the need for histopathology and biopsy in some cases.