People with severe cataracts have higher risk of premature death, study suggests
People who have cataract surgery are more likely to die prematurely, a new study suggests.
They are also more likely to die from issues of the heart and circulatory system, researchers found.
Previous studies have shown conflicting evidence as to whether people who undergo cataract surgery have a higher risk of "all cause mortality", according to experts from China.
So they set out to assess whether those who undergo such operations have a higher risk of different causes of death - such as death from cancer, Alzheimer's and kidney disease.
Cataracts occur when cloudy patches develop on the lens of the eye, over time these can become bigger and cause a loss of vision and even blindness.
Surgery involves replacing the cloudy lens inside with an artificial one.
Hundreds of thousands of cataract operations are conducted every year in the UK.
The new study, published in the British Journal of Ophthalmology, examined data on almost 15,000 people aged 40 and over who took part in the US National Health and Nutrition Examination Survey between 1999 and 2008.
During an average followup period of 10.8 years, almost 4,000 participants died.
And 2,000 had received cataract surgery.
The researchers found that those who had cataract surgery were significantly more likely to have died during the follow-up compared to those who did not – 53 per cent of those who had the operation had died, compared to 15 per cent of those who did not.
But the overall picture masked a slightly complex situation when researchers examined different types of death.
After adjusting for various factors, they found that those who had cataract surgery had a 36 per cent increased risk of dying from vascular disease – which includes issues surrounding the heart and circulatory system.
But there was no statistically increased risk of death from cancer, accident, Alzheimer's disease, respiratory disease or renal disease.
They called for further studies to examine the mechanism behind the findings.
"The current study found a positive association between self-reported cataract surgery and all-cause mortality," the authors wrote.
"In addition, we found that self-reported cataract surgery increases the risks of vascular mortality by 36 per cent after multiple adjustments.
"More studies are needed to confirm these associations and to further investigate the mechanisms behind these associations."
Earlier this month it emerged that scientists have developed a “pellet” implant that is injected into the eye to prevent cataracts forming and could reverse the growth of existing cataracts without surgery.
The implant, thought to work by lowering calcium levels in the eye, is being tested in the first clinical trial.
The implant is loaded with antioxidants and injected into the vitreous — the gel-like fluid between the lens and retina (the light-sensitive area in the eye).
The implant slowly releases its contents into the vitreous, which carries them to the lens where it acts on the cataract.