Patients with diabetes are at an increased risk of developing eye diseases (retinopathy, cataracts, and glaucoma) that can lead to vision loss and blindness. Diabetic eye problems often develop without any noticeable vision loss or pain, so significant damage may already be present by the time patients notice any symptoms. Early detection of diabetic eye disease can help prevent permanent damage.
Diabetic eye problems develop from high blood sugar levels, which can cause damage to blood vessels in the eye. Over 40% of diabetics will develop some form of eye disease in their lifetime. The risk of developing eye problems can be reduced through regular eye exams and by keeping blood sugar levels under control through a healthy diet and regular exercise.
If a person’s diabetes affects the eye, it is called diabetic retinopathy. This is caused by damage to the blood vessels in the retina or the development of abnormal new blood vessels. When diabetic retinopathy is discovered, the ophthalmologist considers several factors before deciding if observation or treatment is most appropriate. If treatment is necessary, the most common procedure is a retinal laser.
What is Diabetic Retinopathy
Diabetic retinopathy is caused by damage to the lining of blood vessels in the retina. These damaged blood vessels develop thinning and may leak fluid, protein, or blood. Additionally, blood vessels may become blocked and this can lead to additional retinal damage due to a lack of oxygen to these tissues. As new blood vessels develop to compensate for this, they can also leak and cause hemorrhages, scarring, and permanent damage to the retina. The risk of developing diabetic retinopathy increases the longer a person has diabetes and the poorer they control their blood sugar levels.
Types of Diabetic Retinopathy
There are several ways to classify diabetic eye disease. It is usually divided into:
Non-proliferative (background) retinopathy
This is the earlier stage of diabetic retinopathy. In this stage, fine blood vessels leak blood, protein, and fluid. This may cause the retina to hemorrhage, swell, or develop protein deposits called exudates. Sight is usually not seriously affected. However, it can rapidly lead to more advanced stages if not treated properly.
This consists of the more serious changes that occur when new, abnormal blood vessels begin growing on the surface of the optic nerve or the retina. These new blood vessels are weaker and more fragile and may rupture and cause bleeding inside the eye. This can lead to severe scarring, retinal detachment, and glaucoma.
The onset and progression of diabetic disease does always follow any pattern. Also, it is possible to develop both forms at the same time, in one or in both eyes.
Detection and Diagnosis
A comprehensive eye examination and appropriate treatment by an ophthalmologist is the best protection against eye damage due to diabetes. This should include a dilated eye exam to examine the stuctures of the eye and will focus on the retina, iris, optic nerve, and eye pressures. Additional testing may be done to evaluate retinal thickness (ocular computed tomography) and evaluate the status of the retinal blood vessels (fluorescein angiography).
When diabetic retinopathy is discovered, your doctor will consider several factors before deciding if observation or treatment is most appropriate. Treatment for early stages of diabetic retinopath usually focuses on maintaining blood sugar levels, blood pressure, and blood cholesterol levels under good control. When ocular treatment is needed, a laser alone, or in combination with a series of intra-ocular injections, is usually used to seal or shrink the abnormal and leaking blood vessels.
In very severe cases, an intra-ocular surgery can be done that cleans out and removes and bleeding inside the eye (vitrectomy). This is a major ocular sugery and may restore some vision, but is primarily done to prevent further ocular damage.
Diabetic Laser Treatments
PRP (Panretinal Photocoagulation)
This is recommended when patients have abnormal blood vessels growing in the eye due to diabetes. These blood vessels are very delicate and are prone to bleeding. This treatment is used to prevent or shrink abnormal blood vessels growing in the eye. This laser treats the periphery of the retina inside the eye. It is NOT used in the central part of the eye. It can be done as a single treatment or as several small treatment sessions.
Argon Focal/Grid Laser
This is recommended when patients have clinically significant swelling of the central retina (macular edema). This laser is used to seal off blood vessels that are leaking blood, fluid, or protein. This in turn coagulates, or dries up, the fluid that is causing the swelling. The laser treats near the center of the retina. This is a very delicate procedure. This may improve vision, but is primarily used to prevent the current problem from worsening.