Research on the links between AMD and sleep dysfunction is limited but suggests a bidirectional relationship, a systematic review found.
The study reviewed 6 studies including 2 case-control studies, 3 longitudinal cohort studies and 1 cross-sectional study published before May 2022.
“In this systematic review, we found that AMD patients had significantly poorer sleep quality and a greater incidence of sleep apnea compared to controls,” corresponding author Raymond P. Najjar, PhD, assistant professor in the Department of Ophthalmology, Yong Loo Lin School of Medicine, National University of Singapore, told HCP Live®. “The converse was also true, with evidence suggesting an association between sleep disturbances (e.g., sleep apnea and insomnia), with a 1.5-3 times increased likelihood of AMD, particularly late-stage AMD. That said, only a limited number of studies investigated these associations between AMD and sleep. More research needs to be done on this topic.”
Only 6 studies met criteria for inclusion in the review. Studies that were not published in English language, qualitative studies, grey literature and papers without full access were excluded.
The review included studies that involved participants with any subtype of clinically diagnosed AMD and those involving participants with any type of sleep dysfunction that evaluated AMD. Sleep dysfunction was explored as an exposure in two studies, AMD was explored as an exposure in one study, and three studies explored either as an exposure.
“We were surprised by the limited number of studies focusing on the associations between AMD and sleep,” Najjar said.
The review found that people with AMD had greater rates of sleep apnea and poor sleep quality and those with sleep apnea and insomnia were at greater risk of developing AMD. Studies evaluataing the relationship between self-reported sleep quality and the likelihood of AMD were conflicting.
Findings of evaluations of AMD as an exposure and sleep quality and/or quantity as an outcome included higher Pittsburgh Sleep Quality Index (PSQI) global scores among participants with AMD compared with controls (6.5 vs 4.5, p=0.013). Another study found that participants with neovascular AMD were 2.84 times more likely to have very bad sleep quality and 3.19 times more likely to use sleep medication than controls.
AMD patients also were more likely to develop sleep apnea, with a large British study showing a rate ratio relative to healthy controls of 1.24.
When AMD was evaluated as an outcome, one study found that clinical diagnosis of insomnia was an independent risk factor for AMD, with an adjusted hazard ratio (HR) of 1.33 (95% CI, 1.18 – 1.48; P <.001). Two other studies showed contradictory findings of the effect of sleep quality on AMD, with one showing that sleeping less than 6 hours was associated with a greater likelihood of neovascular AMD and another finding that sleeping more than eight hours was associated with a greater risk of geographic atropy.
The review also included a finding that participants with sleep apnea were more likely to develop AMD within 10 years than those with sleep apnea (rate ratio [RR], 1.44, 95% CI, 1.32 – 1.57). Another longitudinal study showed that participants with sleep apnea were 1.39 times more likely to develop AMD than controls.
“Based on our findings, clinicians are encouraged to investigate the presence of sleep disorders when treating patients with AMD as part of holistic clinical care,” Najjar said. “Similarly, ocular health should be monitored regularly in patients with clinically diagnosed insomnia, sleep apnea or other sleep disorders for potential early detection and management of AMD or even other ocular diseases like glaucoma.”
More research with better measures of sleep is needed to confirm the relationships between AMD and sleep dysfunction and determine the underlying cause.
“Our investigation highlighted a gap in the objective investigation of sleep quality and quantity in patient with AMD,” Najjar said. “Additional studies, using objective characterization of sleep (i.e., wrist actigraphy, polysomnography) in patients with AMD are required. We are working on that.”
The study, "Associations between age-related macular degeneration and sleep dysfunction: A systematic review," was published online in Clinical and Experimental Ophthalmology.