In vivo confocal microscopic architecture of corneal nerves in a case of multiple endocrine neoplasia type 2b

A detailed ocular examination and in vivo confocal microscopy (IVCM) using the Heidelberg retinal tomograph 3 with Rostock cornea module were performed in a patient with multiple endocrine neoplasia (MEN) 2b syndrome. Ocular findings included ptosis secondary to thickening of the lid margins, subconjunctival and perilimbal neuromas, and prominent corneal nerves extending up to the pupillary area. IVCM demonstrated structural alterations of both the main nerve trunks and the smaller branches. The main nerve trunks were grossly thickened while the smaller fibers were present in an intertwining manner in the anterior stroma. Some fibers showed prominent looping and nodular dilatations at irregular intervals along the length of the nerves. These nodular dilatations were in all probability ganglioneuromas of corneal nerves demonstrated by histopathology in earlier reports of MEN 2b. IVCM may be potentially useful in detecting the nerve alterations in MEN 2b even before other ocular or systemic features become apparent clinically.