Cataracts may be linked to blood pressure drugs

Friday July 24th, 2009

Some blood pressure lowering treatments may be linked to an increased risk of develop cataracts in the eyes, researchers warned today.

Cataracts are extremely common, affecting around a third of people over the age of 65. Hundreds of thousands of corrective procedures are carried out each year, say Dr Paul Mitchell of Westmead Hospital, Sydney, Australia, and colleagues.

The team investigated the potential link between antihypertensive medicine and the rate of cataracts and cataract surgery among 3,654 people aged 49 years or older. Participants were followed for up to ten years.

The results showed that use of beta-blockers (either oral or topical) was associated with cataracts and cataract surgery, even when age, gender, blood pressure, intraocular pressure, myopia, diabetes, smoking and steroid use were taken into account.

Beta-blockers increased the risk of cataracts by approximately 45 per cent, but this was not quite statistically significant. Cataract surgery risk was significantly raised, by 61 per cent.

Use of ACE inhibitors showed a "possible" link to increased risk of cataract surgery. No link was found with diuretics to lower blood pressure.

In the British Journal of Ophthalmology, the researchers conclude: "Users of oral or topical beta-blockers had a higher incidence of both nuclear cataract and cataract surgery."

The drugs may lead to cataract formation by affecting the electrolyte balance of the lens, the experts suggest. It is also possible that calcium levels are affected.

However, the number of participants taking these drugs was small, so the authors write: "These findings should be interpreted with caution". They call for further studies to confirm and understand the findings.

Kanthan, G. L. et al. Use of antihypertensive medications and topical beta blockers and the long term incidence of cataract and cataract surgery. British Journal of Ophthalmology, published online July 23, 2009.

Tags: Australia | Eye Health | Heart Health | Pharmaceuticals

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