Sleep disorders: A risk factor for normal-tension glaucoma?

Purpose: To determine the prevalence of sleep-related symptoms and sleep-re lated breathing disorders by polysomnography in patients with normal-tensio n glaucoma (NTG). Patients and Methods: This comparative case series included 23 patients wit h NTG, 14 NTG suspects, and 30 comparison patients without NTG. A sleep his tory was obtained and determined to be positive or negative. Polysomnograph y was offered for patients with a positive sleep history. Prevalence of a p ositive sleep history and prevalence of sleep disorders were the main outco me measures. Results: The NTG, NTG suspect, and comparison groups did not differ with re spect to age, body mass index, systemic disease, gender, or race. Thirteen (57%) of 23 patients with NTG, 6 (43%) of 14 NTG suspects, and 1 (3%) of 30 comparison patients had a positive sleep history (P = 0.001). Nine of 13 p atients with NTG and four of six NTG suspects with a positive sleep history chose to undergo polysomnography. Seven (78%) of nine patients with NTG an d all four NTG suspects undergoing polysomnography were diagnosed with a sl eep disorder. Five patients with NTG had sleep apnea and two had sleep hypo pnea. Two NTG suspects had sleep apnea; one had sleep hypopnea; and one had upper airway resistance syndrome. The one comparison patient with a positi ve sleep history had upper airway resistance syndrome by polysomnography. Conclusions: Sleep-disturbed breathing may be a risk factor for NTG. Althou gh we do not provide evidence for a cause-and-effect relationship, various physiologic factors produced by sleep-disturbed breathing may play a signif icant role in the pathogenesis of this optic neuropathy. We recommend obtai ning a sleep history from patients with NTG and performing polysomnography in those patients with sleep disturbance symptoms.