Obstructive sleep apnoea (OSA) could be an underappreciated yet important modifiable risk factor for neovascular age-related macular degeneration (nAMD), Australian researchers have found.
The findings, published in the RANZCO Journal of Clinical and Experimental Ophthalmology,1 showed that moderate-to-severe OSA, which results in lower levels of oxygen in the blood overnight, was associated with an increased risk of nAMD compared to those without the condition.
The study was conducted by University of Melbourne Master’s student Attiqa Chaudhary along with members of the Macular Research unit at the Centre for Eye Research Australia (CERA), led by Professor Robyn Guymer AM. They also worked with sleep disorder expert Professor Matthew Naughton from Monash University.2
The team conducted a sleep study involving 225 participants aged over 50 with different stages of AMD and measured their oxygen levels over three nights with a home-based finger oximeter. Their level of obstructive sleep apnoea was calculated based on the oxygen levels in their blood overnight.
Study co-supervisor Dr Carla Abbott said the findings are something clinicians should be aware of.
“Like AMD, sleep apnoea mainly affects people over the age of 50 and many people don’t realise they have it,” Dr Abbott said.
“If this association is validated it may well be worth asking people with high-risk early stages of AMD if they have any symptoms suggestive of sleep apnoea, as treating it might reduce the risk of developing wet macular degeneration.”
“Like AMD, sleep apnoea mainly affects people over the age of 50 and many people don’t realise they have it”
Nocturnal hypoxia
Nocturnal hypoxia often occurs as a result of obstructive sleep apnoea, where a person’s airway becomes blocked or narrowed overnight, reducing their oxygen intake.
A lack of oxygen overnight can cause various health issues over time, but the light-sensitive retina in the eye may be particularly sensitive to small drops in oxygen levels.
“The retina is very active at night – it has its highest need for energy while it recovers from the day,” Dr Abbott said.
Many people diagnosed with sleep apnoea use a continuous positive airway pressure (CPAP) device at night, which helps them breathe easier by providing a constant flow of air through a mask.
“If people aren’t currently getting treatment, it’s putting them at risk over years of not sleeping properly and having low oxygen at night, which could be a contributing factor to macular degeneration, in particular wet AMD,” Dr Abbott said.
Dr Abbott said larger studies will be needed to better understand this association and, if validated, will explore whether treating sleep apnoea has a clinically meaningful impact on reducing progression to nAMD.
References
- Chaudhary A, Abbott CJ, Guymer RH, et al. Nocturnal hypoxia and age-related macular degeneration. Clin Exp Ophthalmol. 2024 Dec;52(9):973-980. doi: 10.1111/ceo.14428.
- Centre for Eye Research Australia, Research: Sleep apnoea associated with macular degeneration (news release, 4 Dec 2024) available at: cera.org.au/research-sleep-apnoea-associated-with-age-related-macular-degeneration [accessed Jan 2025].
