CASE REPORT In Vivo Confocal Microscopy of a Corneoscleral Epithelial Cyst After Spontaneous Marsupialization Ljubisa B. Nikolic, MD, PhD,* Vesna Jovanovic, MD,* and Sladjana Delevic, MD† Purpose: To report a case of an advanced corneoscleral epithelial cyst, healed by a spontaneous marsupialization and analyzed with in vivo confocal microscopy (IVCM). Methods: A 10-year-old boy with a corneoscleral epithelial cyst, which involved the central cornea, was evaluated using IVCM (Heidelberg Retina Tomograph II with Rostock Cornea Module). Results: The cyst emptied through a spontaneously formed minute opening in the anterior corneal stroma. Visual acuity, which had been fluctuating between 20/100 and hand motion, reached 20/50 and remained stable after a 7 months of follow-up. IVCM revealed a moderate haze under the apparently normal anterior stroma. The invading epithelium and highly reflective spheres, which probably are accumulation of desquamated cells and/or shed mucins, were demonstrated in the midstroma and deep stroma, reaching the depth of 125 mm from the uninvolved endothelium. Conclusions: A spontaneous collapse and healing of a corneoscl- eral cyst are possible. IVCM could be useful for the diagnosis and choice of the surgical treatment in the case of a recurrence. Key Words: corneoscleral cyst, in vivo confocal microscopy, epithelial invasion (Cornea 2013;32:880–882) C orneoscleral cyst is a rare condition. Yet, it was described more than a century ago, as can be concluded from the citations found in an article by Fox 1 of Philadelphia, pub- lished in 1928. Its origin is believed to be either traumatic or congenital. 2 It is slow growing and indolent, without a signif- icant inflammatory reaction. 3 Aside from a white spot in the eye, the cyst does not create disturbing symptoms until it crosses the pupillary margin and threatens vision. Surgical approach can provide both the diagnosis and treatment. Empty- ing the cyst of its content by marsupialization 3 or aspiration 4 and the removal of its walls by excision, 2,5 keratoplasty, 6,7 and by peeling yields epithelial cells to be identified by histopathology and enables the stromal repair by apposition of the corneal lamellae. Instead, the cyst may collapse after a dis- charge of its liquid content through a spontaneously created opening in the anterior corneal stroma, and the in vivo histo- pathological diagnosis can be made by using in vivo confocal microscopy (IVCM). To our best knowledge, this is the first report of a case of a corneoscleral epithelial cyst, emptied by a spontaneous marsupialization and visualized by IVCM. CASE REPORT A 10-year-old boy presented with a white corneal spot, which had been present in his left eye for almost 2 years and unresponsive to the topical application of prednisolone and indomethacin during 2 weeks. There was no history of trauma. Visual acuity (VA) in his normal right eye was 20/20. VA in his, also emmetropic, left eye was 20/200. Intraocular pressure was 17 mm Hg in the right eye and 16 mm Hg in the left eye. Biomicroscopy of his left eye revealed a corneal stromal cyst, partially filled with turbid fluid and precipitate with a level (Figs. 1A, B). It extended beyond the limbus and into the sclera at 8-o’clock. The iridocorneal angle was open, without any signs of trauma, and the content of the anterior chamber was clear. The iris, lens, vitreous, and fundus were inconspicuous. The parents refused marsupialization at the limbus or any other kind of surgical therapy, and the patient was followed at 3 months intervals. During that time, the level of the cyst content was fluctuating (Fig. 1C), and VA was changing from 20/100 to hand motion, and back. After 15 months, he appeared with a small, round partial thickness opening in the anterior stroma, below the center (Fig. 1D). The cyst collapsed and the milky content disappeared, leaving a flattened central cornea and moderate haze with a few blood vessels in the posterior stroma. The VA was 20/50. The cyst has not reformed after a 7 months of follow-up. After an explanation of the procedure and acquisition of informed consent, IVCM of the nasal paracentral cornea was performed using the Heidelberg Retina Tomograph II with Rostock Cornea Module (Heidelberg, Germany), as described previously. 8,9 IVCM revealed that the epithelium (Fig. 2A) and the anterior stroma (Figs. 2B, C) were of a normal appearance. A haze appeared in the midstroma (Fig. 2D), just in front of the epithelial ingrowth (Fig. 2E). The epithelium-lined remnants of the cyst in the deep stroma con- tained brightly reflective round accumulations of unknown nature (Figs. 2F, G). A blood vessel was visible at the border of the epithelial sheet (Fig. 2H) and the deep stroma, which showed a moderate haze and highly reflective keratocyte nuclei (Fig. 2I). The endothelium seemed uninvolved (Fig. 2J). DISCUSSION Diagnosis of a corneoscleral cyst can be made at the slit-lamp when a split in the corneal stroma, filled with milky Received for publication December 12, 2012; revision received January 10, 2013; accepted January 11, 2013. From the *Department of Ophthalmology, Faculty of Dental Medicine, Univer- sity of Belgrade, Belgrade, Serbia; and †Eye Hospital “Oculus”, Belgrade, Serbia. The authors have no funding or conflicts of interest to disclose. Reprints: Ljubisa B. Nikolic, Department of Ophthalmology, Faculty of Dental Medicine, dr Subotica 8, Belgrade 11000, Serbia (e-mail: nikolic_ljubisa@ yahoo.com). Copyright © 2013 by Lippincott Williams & Wilkins 880 | www.corneajrnl.com Cornea  Volume 32, Number 6, June 2013