Better Sight Yields Better Sleep. Patients who had cataract surgery also showed improved cognitive function.

by Ed Susman  Contributing Writer, MedPage Today

SEATTLE — Better Sight Yields Better Sleep.Undergoing cataract surgery appears to have more benefits than just improving vision — it may also allow patients to get better sleep and to have better cognitive function, researchers said here.
Sleep efficiency was 85.8% in a fully adjusted multivariate analysis for patients who had undergone cataract surgery, compared with sleep efficiency of 84.4% among patients who did not undergo the surgery (P=0.041), said Kimie Miyata, a staff ophthalmologist at Nara Medical University School of Medicine in Japan.

In her poster presentation at SLEEP 2015, the annual meeting of the Associated Professional Sleep Societies, Miyata also reported that in the fully adjusted model, the risk of being diagnosed with cognitive impairment was reduced 33% in the patients who had undergone cataract surgery (P=0.047).

Individuals with disturbed sleep patterns are more likely than others with normal sleep patterns to have cognitive impairments. The researchers corrected their findings for variables that included age, sex, body mass index, and sleep medication use.
“In the general elderly population, cataract surgery is significantly associated with better objective sleep quality and cognitive function,” Miyata told MedPage Today.
She hypothesized that older individuals — the mean age of those not having cataract surgery in her study was 70.7 years while those who had the surgery had a mean age of 77 years (P<0.001) — may have undiagnosed or untreated cataracts which decrease light reaching the retina. “Circadian rhythm is regulated by the suprachiasmatic nucleus of the hypothalamus, an essential component of the master biologic clock,” she said.
Hence the surgery brings more light to the retina and may allow the individuals to have a more normal circadian rhythm, which manifests in better sleep quality and, in turn, prevention of sleep-modulated cognitive decline.

“This is a fascinating study,” said Rob Weir, MBBS, a sleep researcher and ophthalmologist at Oregon Health and Science University Portland. “Cataracts tend to absorb blue light and blue light is the key wavelength for control of circadian rhythm……..
Source: Medpage Today