What is Diabetic Eye Disease?
Diabetic Eye Disease describes a number of changes that can occur within the eyes as a result of diabetes. These can occur in any type of diabetes (Type 1, Type 2, gestational, etc). Diabetes is one of the largest causes of eye problems in the US, and one of the biggest culprits of blindness in young adults. This is why we (and most primary care doctors and endocrinologists) think annual eye exams are critically important when you have diabetes!
- Diabetic retinopathy – Diabetic retinopathy describes damage to the blood vessels at the back of the eyes. It is broken down into two main categories, non-proliferative (more mild) and proliferative (usually very severe).
- Non-proliferative diabetic retinopathy (NPDR): In early stages of damage, the blood vessels in the back of the eye become leaky as a result of high blood sugar. This allows small amounts of blood and protein to escape from the vessels and sit on top of or between the layers of the retina. Later stages allow significant leakage and changes to the structure of the blood vessels. In many cases, patients do not experience any symptoms, so without regular eye exams they may not know they are having any problems. If the underlying condition is not addressed and blood sugars are allowed to remain too high, the disease will progress to the proliferative stage.
- Proliferative diabetic retinopathy (PDR): In the proliferative form of the disease, the cumulative blood leakage and retinal damage caused by earlier disease encourages the formation of new blood vessels inside the eye. These new vessels can develop between layers of the retina, on top of the retina, or even on the iris (colored structure) located toward the front of the eye. These new blood vessels are very fragile, which makes them a big source of concern inside the eyes. These vessels can leak very large amounts of blood inside the eyes, and can also lead to retinal detachment, retinal cell death, or even a very rapid form of glaucoma. All of these situations can lead to permanent and total blindness.
- Macular edema: This describes swelling that can occur in a patient’s central vision, and can be seen in combination with either NPDR or PDR. This can be sight threatening and will often require treatment.
- Diabetic cataract – while everyone will slowly develop age-related cataracts at some point if they live long enough, diabetes can cause a very rapid onset of cataracts even in young people! This often requires surgical treatment to restore vision.
Other things diabetes can cause:
- Delayed healing – if you develop an injury or infection in one of your eyes, it can take significantly more time to heal for you than for someone without diabetes, and will require careful monitoring by one of our doctors.
- Prescription shifts – if blood sugars are allowed to fluctuate significantly (i.e. when diabetes is undiagnosed or not well controlled) it is possible for your vision to shift dramatically day to day or even hour to hour. This occurs as a result of sugar levels causing the crystalline lens inside your eye (the structure that helps with focusing) to swell or shrink.
- Problems with eye movement or double vision – diabetes can sometimes cause nerve palsies – these are usually temporary paralyses of the muscles that control eye movement and eye position. This can cause you to appear as though you have a lazy eye when you never have before, and can cause you to see double. This needs to be evaluated and managed by an eye doctor to make sure other more serious causes are not at play.
- Loss of corneal sensation – just like diabetes can cause peripheral neuropathy (e.g. loss of sensation in the feet and toes), it can cause a loss of sensation in the clear front tissue of your eye. This means you may not even notice, or not notice as quickly, an injury or infection in your eye.
Do you think you have diabetic eye disease?
People with diabetic eye disease can experience:
- Large fluctuations in vision (one hour your vision is fine, and later everything is very blurry)
- Blurry spots in your vision
- A sudden large dark cloud in your vision
- Areas of vision that are suddenly missing
- A new eye turn or new double vision
If you are experiencing any of these, even if you have not been diagnosed with diabetes, we recommend you come in for an exam. Often a diagnosis of diabetes is only made after an eye doctor finds signs of diabetic eye disease.
If you have any form of diabetes, we recommend that you have your eyes checked annually. If any type of diabetic eye disease is found, we will often recommend more frequent visits.
What causes it?
High blood sugar levels can impact the cells that make up your blood vessel walls, causing them to separate slightly. This allows blood or protein from the bloodstream to leak out of the vessel and sit inside the eye. This leakage of blood can interfere with the normal process of nutrient transfer and delivery to cells in the eye. These cells become “starved” and send out signal molecules indicating they need nutrients. In response, the body can develop whole new blood vessels, usually in areas where blood vessels are not normally found. These new blood vessels are very fragile and can break easily, leading to even larger amounts of blood being released into the eye, or can lead to retinal detachments. If new blood vessels grow up into the angle (the structure in the eye that drains fluid to maintain a low fluid pressure) then a very rapid form of glaucoma can develop.
What to expect at the doctor’s visit/how it’s diagnosed?
At our office, we will perform a thorough evaluation of your vision, prescription, eye movements, and more. We will dilate your eyes, allowing us to see out to the edges of your retina, where we can look for signs of diabetic retinopathy, retinal detachments, and more. We may want to take photos of your retinas to document the level and extent of damage present, and we may perform an OCT (especially if we suspect there may be macular edema present). An ERG can be especially helpful in predicting your risk of progression or worsening.
How is it treated?
One of the best ways to treat diabetic eye disease in many stages (especially early on) is to establish good, tight control over the underlying problem – the diabetes! We will work with you and your primary care doctor and/or endocrinologist to ensure that your daily blood sugar levels and A1C are at optimal levels. We communicate with your other providers after each visit you have in our office, and we can help counsel you on achieving healthy daily habits. Obtaining and maintaining good blood sugar control can minimize daily prescription changes and can reverse more mild levels of retinopathy!
As diabetic retinopathy becomes more advanced or as macular edema develops, treatment by an ophthalmologist may become necessary. These treatments may involve lasers, injected medications, or a combination of those. The goal of these treatments is to try to preserve the healthy retinal tissue that you have left, and vision improvement may not be guaranteed. In the most severe forms of diabetic retinopathy, invasive surgeries may be required to repair retinal detachments, lower eye pressure (to minimize damage from glaucoma), and more.
Diabetic cataracts can cause severe vision impairment, at which point they need to be removed surgically. This surgery is the same one that is performed for normal age-related cataracts. However, you will need to be more closely monitored due to the slower wound healing that occurs in diabetes. If you are young and develop a cataract that must be removed, you may end up needing bifocal glasses after the procedure, as you will no longer have the natural ability to shift your focus from far away to up close. oming soon!