Cataract surgery can reduce the risk of dementia, doctors urge not to ignore visual degeneration

[Health Channel/Comprehensive Report] A global blindness prevention charity has designated June as "Cataract Awareness" month; in the modern aging society, cataracts and dementia have become a major burden on social health. Chen Shiming ophthalmologist Wang Mengqi said on the Facebook fan page "Dr. Wang Mengqi - The Frontline of Ophthalmology" that as they grow older, many elders will feel that the gradual blurring of vision is just a normal phenomenon of aging. However, the latest scientific research reminds us that vision deprivation is actually closely related to brain degeneration. It seems that one is an eye problem and the other is a brain problem, but there is actually an inseparable connection between them.

Wang Mengqi said that although the weight of the eyeball accounts for only one ten thousandth of the body, the cerebral cortex that processes vision accounts for 30 to 50%. "In modern AI language, vision requires a lot of computing power." Therefore, we must understand the impact of "visual deprivation" on the brain.

Wang Mengqi explained that when cataracts block light and visual information from entering the eyes, the stimulation received by the brain will be greatly reduced. In order to compensate for the visual loss, the brain will try to reorganize neural circuits, but this compensation sometimes has adverse effects, making the neural network confusing and inefficient, thereby accelerating the decline of cognitive function.

Wang Mengqi gave an example: The brain is like a high-efficiency factory that needs to constantly process information. When the external raw materials (visual stimulation) are suddenly reduced, the production line responsible for processing vision will be stopped or even abandoned. Over time, the overall brain's operating ability and flexibility will decrease. In addition, poor eyesight often prevents elders from going out, thereby reducing social interaction and causing loneliness; these are also risk factors for aggravating the progression of dementia.

Wang Mengqi said that from a deeper perspective on pathological mechanisms, cataracts and dementia actually originate from a common physiological mechanism, which is "aging and denaturation of proteins." In a healthy eye, the proteins in the lens are very neatly arranged and transparent. However, with age and long-term exposure to oxidative stress such as ultraviolet rays, these proteins will gradually denature, solidify, and aggregate into clumps, causing the lens to become cloudy, which is the cause of cataracts. You can think of this process like the "white" of a raw egg. When the originally transparent protein encounters high temperatures (oxidative stress and aging), it solidifies into a white solid and can no longer transmit light.

Coincidentally, Alzheimer's disease is also caused by the abnormal accumulation of "amyloid protein (Aβ)" in the brain, which in turn destroys the normal function of nerve cells. Surprisingly, scientists not only found this harmful protein in the brains of people with dementia, but also found abnormal amyloid deposits in the lens cells of their eyes. Research also speculates that these harmful proteins may have begun to accumulate in the lens of the eye before accumulating in the brain and causing dementia.

Wang Mengqi emphasized that cataracts must not be regarded as just a minor eye problem. Medical research has confirmed that cataract surgery can not only significantly improve the vision of the elderly, but also effectively reduce the risk of dementia and slow down the decline of cognitive function. By detecting and treating cataracts early, we are not only restoring the vision before our eyes, but we are also re-infusing vitality into the brain. Protecting your eyesight is actually the key first step in protecting your brain from degeneration.

People often ask: "After what age can cataract surgery be performed?" Wang Mengqi believes that there is actually no age limit for surgery. The author has also performed surgery on Renrui. As long as the preoperative assessment determines that it will help vision recovery, the patient can cognitively cooperate, and can follow the doctor's instructions to take medications and follow up after the surgery, the surgery can still restore vision and improve the quality of life.