Link between cataracts and dementia
Last reviewed: 12.03.2022
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Researchers at the University of Washington College of Medicine found that people who had cataracts removed were less likely to get dementia, regardless of its etiology. If a person continues to live with a clouded lens, then the risk of acquired dementia increases significantly.
Dementia is an extremely common syndrome that develops against the background of brain disorders. To date, the pathology is considered incurable. One of the factors in the appearance of persistent progressive dementia is a violation of visual function - in particular, age-related cataracts. Scientists have found that timely restoration of vision significantly reduces the risk of dementia in older people.
The researchers carefully reviewed information about early work on the topic of mental changes in adult patients. The case histories of more than three thousand patients in the age category of 65 years with confirmed diagnoses of glaucoma or lens opacity were studied. When the research project was launched, none of the study participants had a diagnosis of dementia.
During the long-term follow-up, more than eight hundred subjects developed various forms of dementia. Of these, seven hundred patients were diagnosed with Alzheimer's disease . Overall, 45% of all study patients underwent cataract surgery.
Further research showed that people who had cataract surgery had a lower risk of developing dementia of any type by about 30% - and this rate remained stable for at least ten years.
What exactly is the mechanism of the established connection between dementia and cataract is still unknown. Presumably, after correcting the problem of poor vision, patients were able to have better sensory activity, which improved and maintained their cognitive abilities. For example, surgeries that did not improve vision (such as anti-glaucoma interventions) were found not to improve dementia risk scores.
According to another assumption, after the operation, the perception of the blue color gamut, which is usually blocked in cataracts, was restored. This gamma, according to scientists, is used by light-sensitive retinal ganglion structures to regulate circadian rhythms.
The meaning of the surgical intervention is as follows: the doctor removes the clouded lens, and in its place installs an artificial lens that completely replaces the natural organ. As a result, the patient recovers all the visual possibilities that were lost due to cataracts.
Further research should be aimed at improving understanding of the relationship between age-related intraocular changes and brain function. Scientists have to develop possible preventive and therapeutic methods to prevent, slow down or stop the development of age-related dementia.
Source of information about the jamanetwork study