Published: 02 November 2023

Diabetic retinopathy is an eye condition that can affect the retina of people who have diabetes.

The retina is the light-sensitive tissue that lines the back of the eye, and it detects light that is then processed as an image by the brain. Chronically high blood sugar or large fluctuations in blood sugar can damage the blood vessels in the retina. This can result in bleeding in the retina or leakage of fluid.

Diabetic retinopathy can be divided into non-proliferative or proliferative diabetic retinopathy.

Non-proliferative diabetic retinopathy:  In the early stage of the disease, there is weakening of the blood vessels in the retina that causes out-pouching called microaneurysms. These microaneurysms can leak fluid into the retina. There can also be yellow deposits called hard exudates present in the retina from leaky vessels.

Diabetic macula edema is when the fluid leaks into the region of the retina called the macula. The macula is important for the sharp central vision needed for reading and driving. The accumulation of fluid in the macula causes blurry vision.

Proliferative diabetic retinopathy: As diabetic retinopathy progresses, new blood vessels grow on the surface of the retina. These blood vessels are fragile, which makes them likely to bleed into the vitreous, which is the clear gel that fills the middle of the eye. Bleeding inside the eye is seen as floaters or spots. Over time, scar tissue can then form on the surface of the retina and contract, leading to a retinal detachment. This is similar to wallpaper contracting and peeling away from the wall. If left untreated, retinal detachment can lead to loss of vision.

Symptoms of diabetic retinopathy:

• Asymptomatic: In the early stages of mild non-proliferative diabetic retinopathy, the person will usually have no visual complaints. Therefore, it is important for people with diabetes to have a comprehensive dilated exam by their eye doctor once a year.
• Floaters: This is usually from bleeding into the vitreous cavity from proliferative diabetic retinopathy.
• Blurred vision: This can be the result of fluid leaking into the retina, causing diabetic macular edema.

Risk factors for diabetic retinopathy:

• Blood sugar. Lower blood sugar will delay the onset and slow the progression of diabetic retinopathy. Chronically high blood sugar and the longer the duration of diabetes, the more likely chance of that person having diabetic retinopathy.
• Medical conditions. People with high blood pressure and high cholesterol are at greater risk for developing diabetic retinopathy.
• Ethnicity. Hispanics, African Americans, and Native Americans are at greater risk for developing diabetic retinopathy.
• Pregnancy. Women with diabetes could have an increased risk of developing diabetic retinopathy during pregnancy. If they already have diabetic retinopathy, it might worsen during pregnancy.

Published: 02 February 2023

Transition lenses in eyeglasses have been around for many years now. The mechanics behind transition lenses is that certain chemicals in the lens interact with UV light from the sun and turn the lenses dark when you go outside and back to clear when you go inside.

This is a great accompaniment to sunglasses, as it is not always convenient to be carrying around multiple pairs of glasses with you, especially when going from inside to outside frequently. However, there are some drawbacks to transitions, including the fact that they don’t get as dark as sunglasses, have some difficulty turning dark in the car, and have a tendency to keep a slight constant tint even in dark conditions.

Vistakon, the optical wing of Johnson & Johnson, came out with the first transition contact lens a few years ago.  They work well for some people, and don't seem to do a lot for others.

Just a couple personal thoughts: It can look a little strange, depending on the person and the eye color. The material itself turns gray, and therefore the person can be walking around with eyes that look darker than normal. On the plus side, though, this would be good for people limited by high prescriptions and who have difficulty with peripheral vision and glasses, yet still want the transitioning technology. On the other hand, wearing clear contact lenses with sunglasses would provide better sun coverage with the ability to remove the sunglasses when desired.

An area where transition contacts might become very useful is in outdoor sports.  For any athlete who is playing an outdoor sport where the lighting conditions may change from day to day or even within a single game or event, these contacts might significantly improve the ability to perform. This is especially true in any sport where there may be significant contact or rapid head movement that can make it difficult to compete in sunglasses.  

While still in its infancy, transitioning contact lenses look to be a promising technology.

Article contributed by Dr. Jonathan Gerard