Corneal exposure during sleep (nocturnal lagophthalmos).

In our referral practice at the University of Florida, corneal exposure during sleep appears to be a relatively common cause of previously undiagnosed chronic keratitis. The spectrum of the disease ranges from minimal epithelial changes that may heal later in the day to severe exposure ulcers with marked loss of stromal substance. Keratitis sicca and previous lid abnormalities are predisposing factors, but not necessary concomitants of the disease. The diagnosis can usually be made by asking the patient to gently (not forcibly) close his eyes, and usually within a minute or two, a small crack can be seen between the lids by shining light on the intrapalpebral areas-during this time there is usually some fasciculation of the lids. In our experience the most effective treatment, when ointments at bedtime are not adequate, is closing the eye by using a piece of paper tape to pull up the cheek, and then attaching the tape to the forehead, with no pad or pressure on the eye. After the initial healing, ointments at bedtime may be adequate to maintain a symptom-free state in this apparently common cause of treatment-resistant chronic keratitis.