CASE REPORTS Features of the Iridocorneal Endothelial Syndrome on Confocal Microscopy Daniel C. Garibaldi, MD, Oliver D. Schein, MD, MPH, and Albert Jun, MD, PhD Purpose: To present a subtle case of iridocorneal endothelial (ICE) syndrome and discuss the utility of in vivo confocal microscopy in the evaluation of this disorder. Previous reports of the confocal microscopic features of ICE syndrome are reviewed. Methods: A 32-year-old man presented with decreased vision and halos. Slit-lamp biomicroscopy and in vivo confocal microscopy were used to evaluate the etiology of his complaints. Clinical photographs and confocal micrographs were analyzed. Results: In vivo confocal microscopy revealed marked asymmetry between the right and left corneal endothelial layers with pleomorphic epithelioid cells on the right, some with hyperreflective nuclei. A transition between cells with uniform appearance and dark nuclei and a highly irregular cellular arrangement with hyperreflective nuclei was present. Conclusions: This report supports the clinical utility of in vivo confocal microscopy in the evaluation of ICE syndrome. It demon- strates that the histopathologic features of ICE syndrome on scanning electron microscopy may be shown clinically using high-resolution confocal microscopy. Key Words: iridocorneal endothelial syndrome, cornea, confocal microscopy, endothelium (Cornea 2005;24:349–351) T he iridocorneal endothelial (ICE) syndrome represents a spectrum of unilateral disorders of the corneal endothe- lium, anterior chamber angle, and iris, including progressive iris atrophy, Chandler syndrome, and Cogan-Reese (iris nevus) syndrome. Though often associated with little or no visual sequelae, it may progress to disabling corneal edema or visually threatening secondary glaucoma. 1 Abnormalities of the struc- ture and proliferative properties of the corneal endothelium have been implicated in the etiology of ICE syndrome. 2 The high resolution of in vivo confocal microscopy enables the evaluation of all corneal layers in exquisite detail and allows for the detection of even subtle pathology of the corneal endothelium. MATERIALS AND METHODS A 32-year-old man without significant ocular history presented with a chief complaint of decreased vision with halos in the right eye for 4 months. Previous ophthalmic ex- aminations including neuroophthalmic and retinal consulta- tions disclosed pigmented cells on the inferior aspect of the corneal endothelium of the right eye and a possible diagnosis of pigment dispersion syndrome. He was referred to the cornea service for further evaluation. Confocal microscopy was per- formed using the Confoscan 3 (Nidek Inc, Fremont, CA). RESULTS Clinical examination disclosed visual acuity was 20/202 in each eye. Slit-lamp examination disclosed a thick- ened right cornea with deep stromal opacity and pigment deposition on the endothelium, more prominently inferiorly. No other corneal abnormalities were noted. Mild corectopia was present, with the pupil drawn toward an area of peripheral anterior synechiae (PAS) at the 5 o’clock position (Fig. 1A). No ectropion uveae or transillumination defects were present. Gonioscopy disclosed dense pigmentation of the trabecular meshwork for 360 degrees with areas of high PAS (Fig. 1B). Slit-lamp biomicroscopy of the left eye disclosed no abnor- malities. Dilated fundus examination was within normal limits OU. Corneal pachymetry disclosed central thickness of 0.67 OD and 0.58 OS. In vivo confocal microscopy was used to elucidate the etiology of the clinically evident stromal edema OD. This re- vealed marked asymmetry between the right and left corneal endothelial layers with irregular shaped pleomorphic epithe- lioid cells on the right, some with hyperreflective nuclei (Fig. 2A), and normal endothelial cells on the left (Fig. 2B). Based on the clinical examination and confocal microscopic findings, a diagnosis of iridocorneal endothelial (ICE) syndrome was made. DISCUSSION Chiou et al 3 reported 3 patients with ICE syndrome and suggested that 3 types of ‘‘epithelioid’’ presentations may be found on confocal microscopic examination of the posterior Received for publication February 3, 2004; revision received May 14, 2004; accepted May 18, 2004. From the Cornea and Anterior Segment Service, The Wilmer Eye Institute, Johns Hopkins University, Baltimore, MD. Reprints: Albert Jun, MD, PhD, The Wilmer Eye Institute, 600 N. Wolfe Street, Maumenee B20, Baltimore, MD 21287 (e-mail: aljun@jhmi.edu). Copyright Ó 2005 by Lippincott Williams & Wilkins Cornea  Volume 24, Number 3, April 2005 349