Images in Clinical Medicine
Keyhole Pupils
N Engl J Med 2009; 360:1655April 16, 2009
- Article
A 60-year-old man was evaluated for nasal congestion and ocular itchiness that had been ongoing for several years. Examination was unremarkable, showing normal visual acuity, except for symmetric defects in the iris of both eyes (Panels A and B). The patient reported no history of eye injury or eye surgery, having had “keyhole” pupils for as long as he could remember. The results of slit-lamp and fundus examinations were normal, and the patient had normal neurocognitive development. On the basis of these findings, a diagnosis of isolated bilateral iris coloboma was made. His nasal and ocular symptoms were found to be due to chronic allergies. Colobomas are the result of abnormal closure of the optic fissure, which normally occurs during the fifth week of gestation. They may occur anywhere along the optic fissure and can affect the iris, choroid, or macula. Isolated iris colobomas are asymptomatic, but those involving the macula or the optic disk can result in severe visual impairment. Typical iris colobomas occur in the inferonasal quadrant, as seen in this case.
Smita I. Negi, M.D.
Guha Krishnaswamy, M.D.
East Tennessee State University, Johnson City, TN 37604
