As we age, eye conditions such as cataracts and glaucoma increase, but diabetes is another cause of loss of vision and blindness in older adults.
Dr. Ethan Payne, an ophthalmologist at Pocono Eye Associates in Brodheadsville, an independent provider with the Lehigh Valley Health Network, said the most common cause of a decrease in vision or loss of vision in adults is diabetic retinopathy.
Cataracts are common in people over 50 years old, and macular degeneration is the most common cause of blindness in people 70 years old and older, in particular in Caucasian people.
Macular degeneration has more of a genetic component, but diabetes can make cataracts and glaucoma worse, he said. It can lead to early cataract formation and certain kinds of glaucoma. Glaucoma is a condition involving the optic nerve, which carries visual information to the brain.
Payne said it isn’t known for certain how blood sugar levels damage eyesight, but they have a theory.
“We suspect that hyperglycemia damages the little capillary vessels, in particular the endothelial wall or the inside wall where the blood is traveling. It damages those endothelial walls and that leads to the little capillary vessels getting scarred off, so blood doesn’t travel to them very well anymore. You get areas of the retinae that are not getting good blood flow to them anymore,” he said. “Those areas get damaged, then some of those blood vessels start to leak. They leak blood and fluid into the retinae, so you get swelling of the retinae and that leads to vision loss.”
The best way to prevent diabetic retinopathy is to control blood sugar levels and have a comprehensive eye exam.
In the very early stages, a person would not know they are developing diabetic retinopathy, because it doesn’t affect vision. But an eye doctor can alert people to the condition so they can control their blood sugar better and save their eyesight.
As for cataracts, they are part of the aging process, and most people develop them the older they get.
“The way that the lens cells replicate and the way that they change over time leads to a discoloration of the lens and a clouding of the lens,” Payne said. “Light can no longer easily pass through the lens.”
This causes a person to feel like they are struggling to see, he said.
“Cataracts have a very well-established treatment,” he said.
The surgery involves removing the lens and replacing it with an artificial lens.
“It can really restore somebody’s eyesight in basically a 15-minute procedure. It’s very common,” Payne said.
For people who are nervous about the surgery, general anesthesia can be used in some cases, but more often a twilight anesthesia is used, as well as local anesthesia.
Glaucoma, another condition that can cause vision loss, is an umbrella term for a group of conditions that causes a disorder of the optic nerve, Payne said. The most common is increased eye pressure. When it gets too high, an eye doctor can prescribe a medication that is applied by drops to the eye. In serious cases, laser treatment may be necessary, Payne said.
There are other factors that can affect eyesight, such as sunlight.
Ultraviolet light from the sun can damage certain parts of the eye. A lot of exposure can lead to cataract formation and can damage the retinae as well.
“Protecting your eyes from sunlight is important,” Payne said.
Smoking is also known to cause eye damage. It can lead to early cataract formation and worsen blood vessel damage caused by diabetes or high blood pressure, he said.
And it is always important to wear safety glasses when working with tools that can cause small pieces of an object to fly off and possibly get into the eyes.
Staying active and exercising, as well as a good diet can help keep the eyes healthy. A good diet can help with macular degeneration, in particular.
Payne recommends having a diet rich in dark leafy green vegetables, and omega 3 fatty acids from foods like fish.
“We recommend taking certain vitamins that have vitamin C, D, zinc, lutein, that you can find in a healthy diet. That’s important,” he said.
Contact lens hygiene is also very important. Payne does not recommend sleeping in contact lenses, even those that the manufacturer says can be worn all night.
He also warns against wearing contact lenses for too long during the day. This can cause fatigue to the eye. It can also cause the surface of the eye to become inflamed. Infections of the cornea can also develop.
“You have to keep them clean and replace them when they need to be replaced,” he said. “Go throughout the weekend without them. Give your eyes a rest.”
Screen time can also cause a lot of fatigue. Payne said it is not known if screen time can damage the eyes, but breaks are a good idea, and lower the brightness.
“There is a 20-20-20 rule: every 20 minutes, take 20 seconds and look at something at least 20 feet away,” he said. “That gives your eyes a break basically.”