Study suggests link between statin use and reduced risk of cataract surgery

Statins have an antioxidant effect that may inhibit the development of cataract after extended use.

Issue: April 25, 2012

Long-term statin use was associated with a lower risk of cataract surgery, and short-term use correlated with an increased risk, according to a large study.

Statins are known to reduce serum cholesterol levels but may also have an antioxidant effect that prevents the development of cataract, the study authors said.

“The reason that only longer-term use is protective against cataract surgery is that once cataracts have formed, it seems unlikely that treatment could then repair damaged lens proteins,” Donald S. Fong, MD, MPH, lead study author from Kaiser Permanente Southern California, said in an email interview. “It seems that statin use would need to be started earlier, when the patient is younger, and be taken for longer for any protective mechanism to work.”

The increased risk of cataract surgery with short-term statin use does not suggest that short-term use causes cataracts, Dr. Fong said.

“Our observations may simply mean that the treatment was just started,” he said. “So, shorter-term statin use may simply mean that you are starting to control imbalances that are also associated with cataracts.”

The study was published in the American Journal of Ophthalmology.

Study design and methods

The case-control study examined medical records of patients older than 50 years who were enrolled for at least 5 years in a large HMO in California.

The study group comprised 13,982 patients who underwent cataract surgery. A control group included 34,049 patients who underwent eye examinations but did not have cataract surgery or diagnosis of cataract in their medical records.

Investigators evaluated patients’ use of the statins atorvastin, ezetimibesimvastatin, lovastatin, pravastatin and simvastatin, as well as other lipid-lowering agents such as cholestyramine, colestipol, ezetimibe, fenofibrate and gemfibrozil.

The researchers also analyzed comorbidities such as coronary artery disease, smoking status and diabetes and demographic factors such as age, sex, race, ethnicity and socioeconomic status.

“Because we had a very large study, all these factors were statistically significant,” Dr. Fong said. “This is what happens when you have a large and diverse population that is broadly representative of the southern California region. These factors are thought to be related to both statin use and cataract surgery. Understanding how these demographic factors might modulate the effect of statin use on cataract surgery is definitely a subject for future studies.”

Results and conclusions

Study results showed that patients who had cataract surgery were predominately older and white and appeared to have more coronary artery disease but less diabetes than other groups.

The proportion of statin users was higher among subjects who had undergone cataract surgery (64.3%) than those who had neither undergone cataract surgery nor had a diagnosis of cataract (55.5%).

Data adjusted for age, sex, race, smoking status, diabetes and coronary artery disease showed a statistically significant association between longer-term statin use and a lower prevalence of cataract surgery (P = .02). There was a statistically significant association between shorter-term statin use and cataract surgery (P < .0001).

Age-adjusted data showed that 5 years or more of statin use was associated with a lower prevalence of cataract surgery in patients aged 50 to 64 years. Statin use of less than 5 years was associated with an increased risk of surgery in younger patients and those older than 60 years.

Women between the ages of 50 and 64 years had a lower risk of cataract surgery than those older than 65 years.

Asian Americans were more likely and African Americans and Hispanic Americans were less likely than white subjects to undergo cataract surgery, the authors said. – by Matt Hasson

Reference:

Fong DS, Poon KT. Recent statin use and cataract surgery. Am J Ophthalmol. 2012;153(2):222-228.

For more information:

Donald S. Fong, MD, MPH, can be reached at Clinical Trials Research, SCPMG, 100 S. Los Robles, Pasadena, CA 91101; email: donald.s.fong@kp.org.
Disclosure: Dr. Fong has no relevant financial dislosures.