SAN FRANCISCO — The ability of cataract surgery to restore sight is well known. People say they’re stunned by the vibrancy of color after surgery and the improvement in night vision. Some can even reduce their reliance on glasses. But can you quantify that improved quality of vision? To find out, researchers in Australia used a driving simulator to test patients’ vision before and after cataract surgery. They found that near misses and crashes decreased by 48 percent after surgery. The researchers present their study today at AAO 2019, the 123rd Annual Meeting of the American Academy of Ophthalmology.
Cataracts are a normal consequence of aging. They happen gradually over years, as the clear lens inside the eye becomes cloudy. The effects of a developing cataract are sometimes hard to distinguish from other age-related vision changes. You may become more nearsighted; colors appear duller and glare from lights make it harder to see at night. By age 80, about half of us will have developed cataracts.
Cataract surgery replaces the cloudy lens with an artificial lens. The surgery is low-risk, fast and effective. But not everyone has surgery right away. The decision is usually based on how much the cataract is interfering with daily life activities. Ophthalmologists typically operate on one eye at a time, starting with the eye with the denser cataract. If surgery is successful and vision improves substantially, sometimes surgery in the second eye is forgone or delayed. However, most people get significant benefits from having surgery on the second eye. Depth perception is improved, vision is crisper, making reading and driving easier.
To better understand the true benefit of cataract surgery to patients’ quality of life, Jonathon Ng, MD, and his colleagues at the University of Western Australia, tested the driving performance of 44 patients before they had cataract surgery. The driving simulator assessed a variety of variables: adjusted speed limits, traffic densities, uncontrolled intersections and pedestrian crossings. Patients were put through the driving simulator again after their first surgery and then again after their second eye surgery. After the first, near misses and crashes decreased by 35 percent; after the second surgery, the number fell to 48 percent.
While visual acuity – how well one sees the eye chart – is an important method to assess a person’s fitness to drive, it’s an incomplete assessment, Dr. Ng said. Quality of vision is also an important indicator. Improved contrast sensitivity and better night vision improves drivers’ safety on the road.
“In Australia and other countries, people may often wait months to receive government funded surgery after a cataract is diagnosed,” said Dr. Ng. “These results highlight the importance of timely cataract surgery in maintaining safety and continued mobility and independence in older adult drivers.”
Some things to consider, when considering cataract surgery: