Study: Statins May Increase Cataract Risk

September 20, 2013

News Review From Harvard Medical School -- Study: Statins May Increase Cataract Risk

People who take statin drugs to lower cholesterol may be more likely to develop cataracts, a large new study finds. Previous research has had mixed results. Some studies found a higher risk of cataract for people who took statins. Others found a lower risk. The new study included two groups of veterans, both men and women. The first part of the study focused on 14,000 veterans. Half took statins. They were compared with others who did not take statins but were otherwise similar. Each person was assigned a score based on age, diabetes, smoking and many other factors. The factors were chosen because they could affect people's risk of having cataracts or needing to take statins. Researchers compared people with similar scores. Those who took statins were 9% more likely to have cataracts than those who didn't take statins. Researchers also did a second analysis in a different group of 33,500 patients. People in this group did not have any other major illnesses. Researchers also adjusted these numbers for other factors affecting risk. Statin users were 27% more likely to be diagnosed with a cataract compared to non-users.  The authors say patients should not stop taking a statin based on the study results. The journal JAMA Ophthalmology published the study. HealthDay News wrote about it September 19.

By Howard LeWine, M.D.
Harvard Medical School

What Is the Doctor's Reaction?

Medicines called statins are some of the most widely prescribed drugs. They lower cholesterol. But, more importantly, statins reduce the amount of fatty build-up in arteries. This means much less chance of having a heart attack or stroke.

If you need a statin, you are likely to remain on it for many years. So it's important to keep looking for potential long-term side effects. One of the concerns about statins has been an increased risk of developing cataracts.

Each of our eyes comes equipped with a lens. It's tucked in just behind the pupil. The lens focuses light on the retina in the back of the eye.

When we're young and spry, our lenses are usually crystal clear. But by the time we're in our 60s or 70s, a lifetime of exposure to light and other factors can "cook" the protein inside the lenses. They cloud up, a little like the white of an egg in a frying pan.

A clouded-up lens is called a cataract. A cataract blurs details, dulls colors and makes seeing at night difficult.

Cataracts are typically small to begin with. Both lenses tend to be affected. But often one is more clouded than the other.

Cataracts are part of the aging process. Everyone gets them, if they live long enough.

Some studies have suggested that statins might actually help prevent cataracts. And some have found opposite results, a higher risk of cataracts in statin users. This new study found a similar link -- more cataracts among people taking statins.

What Changes Can I Make Now?

If you take a statin, don't stop based on the findings in this study. Given that other studies have not shown similar results, the jury is still out regarding statins and cataracts. And the health benefits of statins clearly outweigh a greater cataract risk, if it exists at all.

Also, it's important to remember that this is an observational study. This type of study can only show a connection between statin users and a possible risk of developing cataracts sooner.  But those who developed them were destined to develop them anyway. So taking a statin surely can't be the only reason for getting cataracts.

You can reduce your risk of developing cataracts earlier in life:

• Don't smoke -- and if you do, quit. Smoking doubles the risk of getting a cataract. If you quit, the risk declines. But it may never disappear altogether.
• Protect your eyes from sunlight. Exposing your eyes to ultraviolet B (UVB) light increases your risk of developing cataracts. UVB is part of the light spectrum that causes sunburn. Sunglasses block UVB. In general, the darker the lens, the more UVB it blocks. Wearing a brimmed hat also helps protect your eyes from UVB light.
• Watch your alcohol consumption. Drinking alcohol slightly increases the risk of cataracts. The more you drink, the greater the risk.
• Exercise and maintain a healthy way of life to help prevent type 2 diabetes. People with diabetes tend to develop cataracts at an earlier age. If you have diabetes, better blood sugar control helps delay lens clouding.
• Eat plenty of fruit and vegetables. The antioxidants in fruits and vegetables help prevent macular degeneration, another age-related eye disease. But they also may delay the onset of cataracts. This may be especially true for lutein and zeaxanthin. They are carotenoids found in leafy green vegetables. Examples are kale, spinach and collard greens. 

What Can I Expect Looking to the Future?

The question of increased cataract risk remains. Unless better medical evidence shows that statins cause cataracts at a much younger age than expected, it won't influence who should take a statin.