Association between Glaucoma and Obstructive Sleep Apnea Syndrome: A Meta-Analysis and Systematic Review

Abstract

BackgroundObstructive sleep apnea syndrome (OSAS) is a common disease that increases the risk of diabetes, heart disease, and stroke. However, studies of an association between OSAS and glaucoma neuropathy have reported controversial findings.ObjectiveThe main purpose of this study was to evaluate whether a significant association exists between OSAS and glaucoma by performing a meta-analysis of previous studies.MethodsA comprehensive literature search using the PubMed and Embase databases was performed to identify cross-sectional, case-control, and cohort studies related to the topic. We estimated a pooled odds ratio (OR) for the association between OSAS and glaucoma, by a fixed- or random-effects model.ResultsIn total, 16 studies with 2,278,832 participants met the inclusion criteria: one retrospective cohort study reported an adjusted hazard ratio of glaucoma of 1.67 (95% CI = 1.30–2.17). Using a fixed-effects model, the pooled OR of six case-control studies was 1.96 (95% CI = 1.37 2.80). A significant association was also identified in a meta-analysis of nine cross-sectional studies using a random-effects model, which showed a pooled OR of 1.41 (95% CI = 1.11 1.79). However, the reported pooled estimates for case control studies and cross-sectional studies were based on unadjusted ORs.ConclusionsOur results suggest that OSAS is associated with the prevalence of glaucoma. However, this result was based only on unadjusted estimates. Prospective cohort studies designed to take into consideration potential confounders, or examination of data from interventional trials to determine whether a reduction in OSAS status is associated with a reduced incidence of glaucoma, are needed to clarify whether OSAS is an independent risk factor for glaucoma.

Ocular Manifestations of Obstructive Sleep Apnea

“…Among cohort studies, the same meta-analysis found an OR of 1.43. 18 Another meta-analysis by Huon et al used six case-control studies with 1,122 glaucoma cases and 7,122 controls. The study found an overall OR for OSA of 1.746 among individuals with glaucoma.…”

“…OSA predisposes the optic nerve head to ischemia and damage through episodes of hypoxia, hemodynamic changes to retinal blood vessels, oxidative stress, mitochondrial dysregulation, and inflammation. 18,20,21 This proclivity to damage leads to the nerve fiber dysfunction and degeneration seen in glaucoma. Patients with OSA may possess optic nerve heads more sensitive to mechanical damage given their poor perfusion and potential for ischemic changes.…”

“…Patients with OSA may possess optic nerve heads more sensitive to mechanical damage given their poor perfusion and potential for ischemic changes. 18 However, the association between OSA and glaucoma remains subject to potential confounding factors, such as conditions associated with poor blood supply to the optic nerve head including obesity, hypertension, and diabetes.…”

Glaucoma Chronic Angle-Open, Endocrinopathy and Obstructive Sleep Apnea Syndrome: Fortuitous Association or Interaction?

“…In the last years of the past century stress was laid on the importance of pressure disorders in subjects with Obstructive Sleep Apnoea Syndrome (OSAS) [13] , for which, as is well known, endocrine pathology is one of the predisposing conditions. The fact is that the functional alterations of almost all the endocrine glands (pituitary, thyroid, adrenal capsules, ovary, pancreas) involve an increase in bodily weight with accumulation of fat, above all in the organs that favour frequent episodes of collapse of the upper airways during sleep.…”

“…In glaucoma associated with an increase in IOP, OSAS may act, instead, by further increasing IOP through an increase in sympathetic tone and an alteration of the architecture of sleep [13,20] . Hence the increased frequency of glaucoma during endocrinopathies would not be an accidental coincidence, but, on the contrary, a component of the endocrinopathy, which would play its role both directly and, above all, by triggering the onset of OSAS.…”