Some antidepressants may raise cataract risk: study

People who take certain drugs for depression known as selective serotonin reuptake inhibitors (SSRIs) may have a higher-than-average risk of developing cataracts, a study from Canada hints.

Among about 18,700 Quebec residents aged 65 and older with cataracts and 187,000 age-matched Quebec residents without cataracts, study chief Dr. Mahyar Etminan, of Vancouver Coastal Health Research Institute and University of British Columbia, and colleagues found that people taking SSRIs were 15 percent more likely to be diagnosed with cataracts than those not taking these drugs.

While the study does not allow for calculating a person’s actual risk of developing cataracts with SSRI use, Etminan noted that the average lifetime risk of developing cataracts for someone in North America above the age of 50 is approximately 20 percent.

In general, SSRIs roughly increase the risk to 23 percent, the researcher noted.

However, “SSRI therapy should not be stopped for fear of cataracts, which are treatable and relatively benign,” Etminan told Reuters Health.

“The benefits of treating depression, which can be life-threatening, still outweigh the risk of developing cataracts,” the researcher emphasized.

Different SSRIs may pose different risks. For example, current users of fluvoxamine (Luvox) had a 39 percent higher chance of being diagnosed with cataracts and a 51 percent higher chance of having cataract surgery. With venlafaxine (Effexor), one’s risk may be roughly 26 percent higher than average and with fluvoxamine, it may be 30 percent higher.

Current venlafaxine (Effexor) users had a 33 percent higher likelihood of cataracts and a 34 percent higher likelihood of cataract surgery, while taking paroxetine (Paxil) carried a 23 percent higher risk of cataract surgery.

In the current study, current use of fluoxetine ( Prozac), citalopram (Celexa), and sertraline (Zoloft) did not seem to raise the odds of cataracts or cataract surgery. And past use of any SSRI also did not appear to pose a risk.

“We found different risks with different agents. However, we don’t want to dwell on this with just one study and think whether the risk is different with different agents should be validated in future studies,” Etminan said.

Smoking is a key risk factor for cataracts and “the main limitation of the study,” Etminan told Reuters Health, “is not being able to control for smoking as this information was not available.”

Still, this is the first study to find a link between SSRI antidepressants and cataracts in humans, while earlier studies have suggested that was true in animals.

Nonetheless, the study does not prove that taking SSRIs can cause cataracts; it only reveals an association between the two. Clearly, more study is needed, the researchers conclude.

SSRIs are one of the most frequently prescribed class of drugs in the US and the third most prescribed class globally.

SOURCE: Ophthalmology, published online March 8, 2010.