Evaluation of Corneal Microstructure in Pseudoexfoliation Syndrome and Glaucoma: In Vivo Scanning Laser Confocal Microscopic Study

Purpose: To quantitatively evaluate corneas of patients with pseudoexfoliation syndrome (PXS) and pseudoexfoliation glaucoma (PXG) using in vivo scanning laser confocal microscopy (IVCM). Materials and Methods: The study population comprised 30 patients with PXS, 30 patients with PXG, and 30 normal control subjects. IVCM of the cornea was performed on all participants using the Rostock Cornea Module of the Heidelberg Retinal Tomograph (HRT). Mean outcome measures included density of basal epithelial cells, endothelial cells, and anterior and posterior keratocytes; and tortuosity and density of subbasal plexus nerves. Results: Mean densities of basal epithelial cells, endothelial cells, anterior and posterior keratocytes, and subbasal nerves differed significantly among the three groups. Subbasal nerve densities were significantly diminished in PXS and PXG patients (12.362.89 and 6.8 +/- 3.42mm/mm(2), respectively) compared with that of control subjects (16.13 +/- 3.42mm/mm(2)) (p<0.05). Mean densities of anterior and posterior stromal keratocytes were significantly lower in PXS and PXG patients compared with control subjects (p<0.05). Endothelial cell densities were 3073.63 +/- 654.49, 2592.60 +/- 276.36, and 2110.20 +/- 620.53 cells/mm(2) for control, PXS, and PXG groups, respectively (p<0.05). The percentages of endothelial cell polymegathism and pleomorphism were higher in PXS and PXG patients compared with control subjects. Endothelial cell polymegathism and pleomorphism were more frequently associated with PXG. Conclusions: Results of this study demonstrate the existence of alterations in the (i) density of cells in the various layers of the cornea, (ii) cellular configuration of corneal endothelial cells, and (iii) density/diameter of the subbasal nerve plexus in patients with PXS, and that such alterations are common in patients with PXG. It would be beneficial to employ IVCM to assess the severity of pseudoexfoliation keratopathy (PXK).