The eye and sleep.

BACKGROUND: Sleep-associated disorders of the eye are increasingly recognized. Disordered sleep has also been found in some blind patients.
METHODS: Review of the current state of knowledge of sleep-related eye disorders and blindness-related sleep disorders.
RESULTS: Incomplete eyelid closure during sleep (lagophthalmos) may be physiological but in some patients can cause significant symptoms. Nocturnal lagophthalmos may be a limiting factor in the surgical repair of some eyelid and orbital disorders. Normal eyelid closure has also been linked to the development of a number of ocular surface disorders. Sleep disorders are common, and obstructive sleep apnoea (OSA) the commonest. OSA is associated with a number of serious systemic diseases and also several eye disorders including floppy eyelid syndrome, optic neuropathy, glaucoma, anterior ischaemic optic neuropathy and papilloedema secondary to raised intracranial pressure. Treatment of OSA may help floppy eyelid syndrome, halt progression of associated glaucoma, and reduce intracranial pressure in patients with associated papilloedema. The diagnosis of OSA can only be made with formal sleep studies, but asking a small number of appropriate questions will help screen those patients who should be referred for sleep studies. Some blind patients have disordered sleep patterns due to disruption of the retinal input into the hypothalamic-pineal melatonin secreting apparatus. This can be alleviated by oral administration of melatonin.
CONCLUSIONS: Ophthalmologists should be aware of sleep-associated eye disorders and refer appropriate patients for formal sleep studies. Sleep abnormalities in blind patients should be enquired about and patients offered assessment and treatment by a sleep physician.