Conjunctival Modifications in Ocular Hypertension and Primary Open Angle Glaucoma: An In Vivo Confocal Microscopy Study

PURPOSE. The study was conducted to analyze, by in vivo confocal microscopy (IVCM), the conjunctival epithelial characteristics in untreated ocular hypertension (OH) and in topically treated primary open-angle glaucoma (POAG). METHODS. The study included 30 eyes affected with untreated OH, 96 eyes with POAG receiving medical therapy, and 15 healthy control eyes. The main outcome measures were the mean density and the mean area of conjunctival epithelium microcysts. The relations among the microscopic parameters intraocular pressure (IOP), and age in both hypertensive and glaucomatous eyes and between mean defect (MD) of visual fields and the time on therapy in patients with glaucoma were analyzed. RESULTS. There was no evidence of conjunctival microcysts in any of the healthy eyes examined; conversely, conjunctival microcysts were found in all ocular hypertensive eyes (mean microcyst density of 19.7 3.5 cysts/mm2 and mean total microcyst area of 4063.6 921.2 m2). All patients with POAG showed conjunctival microcysts (mean density of 28.7 2.7 cysts/mm2 and a mean total microcyst area of 6564.2 671.4 m2). No significant differences were found between OH and POAG subjects for microcyst parameters and no significant relations were found in either OH or POAG eyes for microcyst density, area, IOP, MD, and time on therapy. CONCLUSIONS. The results of the study show that conjunctival microcysts are features present in all hypertensive and glaucomatous eyes. Based on these findings, conjunctiva could be an additional potential target tissue available for the investigation by a noninvasive in vivo approach of glaucoma-induced pathologic modifications.