Obstructive sleep apnoea

Abstract

Obstructive sleep apnoea (OSA) is increasing in prevalence due to rising obesity. While OSA is a disorder primarily of the upper airway during sleep, its pathophysiological impact on other body systems is increasingly recognised. There has been interest in the prevalence of OSA in different ophthalmic conditions and possible causation has been postulated. As OSA is common, it can be expected that people with co-existent OSA will be found in any ophthalmic disease population studied. To determine with confidence the significance of finding patients with OSA in a particular cohort requires a well matched control group, ideally matched for age, obesity, gender and co-morbidities. Only if one can say with certainty that the prevalence of OSA is higher in a group with a particular co-existent ophthalmic disease can we begin to speculate about possible mechanisms for the overlap in these conditions. Possible mechanisms for how OSA might affect the eye are discussed in this review. The current literature is reviewed with respect to diabetic retinopathy, glaucoma, floppy eyelid syndrome, non-arteritic ischaemic optic neuropathy, keratoconus and AMD. Associations with OSA have been found, but robust prospective studies using multi-channel sleep studies to diagnose OSA are lacking. Gaps remain in the evidence and in our knowledge. It is hoped that this review will highlight the need for ophthalmologists to consider OSA in their patients. It also makes recommendations for future research, especially to consider whether therapies for OSA can also be effective for ophthalmic disorders.

Fig. 1

Screening tool to assess a patient for OSA, taken from obstructive sleep apnoea – a Guide for GPs, British Lung Foundation 2012

Fig. 2

Photograph showing continuous positive airway pressure (CPAP) therapy being used, with machine, humidifier, tubing and face mask (consent obtained)

Fig. 3

Potential mechanisms by which obstructive sleep apnoea causes retinal vasculature damage and eye disease

Fig. 4

Forest plot of the pooled estimate of the effects of minimum oxygen saturation on diabetic retinopathy using a random effects model; from a meta-analysis by Leong et al. [72]