Increased cataracts risk in elderly associated with SSRIs, SNRIs

Key Points

In an on-line article published in the journal Ophthalmology, researchers reported a possible adverse association between certain selective serotonin reuptake inhibitors (SSRIs) and serotonin and norepinephrine reuptake inhibitors (SNRIs) and the development of cataracts in those aged >65.

The article details the results of a nested case-control study, which utilized a cohort of residents from Quebec, Canada, aged >65 years who had undergone coronary revascularization between 1995 and 2004. Within this population, researchers identified 18,784 patients diagnosed with cataracts (cases) and 187,840 patients without a diagnosis (controls) by an ophthalmologist (ICD-9 code 366). Of these, 5.7% of cases and 4.4% of controls were receiving an SSRI or the SNRI venlafaxine.

The researchers, led by Mahyar Etminan, PharmD, MSc, from the Center for Clinical Epidemiology and Evaluation, Vancouver Coastal Health Research Institute, Vancouver, Canada, found a 15% (95% CI, 8%–23%) increase in the adjusted relative rate of developing cataracts among current users of SSRIs or SNRIs (mean time to diagnosis of cataracts was 656 days). However, this risk appeared to be confined to current users; as past SSRI or SNRI use was not found to be associated with an increased risk. Furthermore, the relative increase in the rate of cataract development was independently associated with fluvoxamine (39%; 95% CI, 7%–80%) and venlafaxine (33%; 95% CI, 14%–55%). When cases were restricted to those who underwent outpatient surgical treatment for cataracts, similar results were seen except paroxetine was also found to be an independent predictor for the need for cataract surgery (23% increase in relative rate; 95% CI, 5%–45%).

Interestingly, this study did not show a statistically significant increase in the risk of cataracts with other SSRIs including citalopram, fluoxetine, or sertraline. However, the researchers noted, "our study may have lacked adequate power to assess the risk of cataracts with all individual antidepressants."

In their paper, a large sample size, access to detailed prescription drug data, and an ability to assess individual SSRIs were highlighted as study strengths by the researchers. Noted limitations included the researchers' inability to adjust for many potential risk factors for cataracts, particularly smoking history, and the likelihood that some control patients may have had undiagnosed cataracts because of the relatively short duration of patient follow-up (2.8±2.2 years).

Currently, it is estimated that as many as 10% of Americans are receiving an antidepressant, mostly SSRIs and SNRIs. Based upon these figures and their study's results, the researchers suggested that roughly 22,000 cases of cataracts may be avoided secondary to SSRI use in the United States each year.

The researchers suggested, "Future studies are needed to confirm this association in other populations."

SOURCES

Etminan M, Mikelberg FS, Brophy JM. Selective serotonin reuptake inhibitors and the risk of cataracts a nested case-control study. Ophthalmology. 2010.117(6):1251–1255.

Olfson M, Marcus SC. National patterns in antidepressant medication treatment. Arch Gen Psychiatry. 2009;66:848–856.