Having poorly regulated control of diabetes or having diabetes for a prolonged period of time can progressively damage the eye, resulting in a condition called diabetic retinopathy (DR). Diabetic retinopathy (DR) refers to abnormalities in the blood vessels surrounding the retina (the eye) for reasons related to having diabetes, such as hyperglycemia, high cholesterol levels, and high blood pressure. DR must be detected and managed early in the process to prevent its potential progression into vision loss or other serious conditions. A routine eye exam, therefore, consists of one of the several important check-ups for those diagnosed with diabetes.
What are the stages of diabetic retinopathy?
There are two main stages of diabetic retinopathy: non-proliferative diabetic retinopathy (NPDR) and proliferative diabetic retinopathy (PDR), with the latter being the more advanced stage. The former stage, NPDR, is characterized by blood leaking from hemorrhages and micro-aneurysms of the retinal blood vessels, as well as, narrowing and blockage of the vascular structure.
Eventually, in efforts to compensate for this loss of properly functioning blood vessels, new blood vessels start to form around the retina, also known as retinal neovascularization. These abnormal veins, however, will easily leak into the vitreous humor. Neovascularization can lead to detrimental complications that can directly cause vision loss. These include diabetic macular edema, swelling of the center of retina due to fluids leaking from the blood vessels, and traction retinal detachment, caused when neo-vasculature matures into scar tissue that pull the retina as it contracts.
What are the symptoms?
Diabetic retinopathy (DR) may begin with no symptoms. As it progresses, the damage to the blood vessels may cause floaters, dark or missing spots in vision, blurred or fluctuating vision, and eventually, vision loss.
What should I expect in my routine eye exam?
The ophthalmologist will conduct a visual acuity test to observe any significant changes in the clarity of vision. Other exams, such as visual field test (checking peripheral vision), eye muscle function test (checking movement of muscles around the eyeballs), pupil response test (testing response of pupils to light), and tonometry test (measuring eye pressure), may be done.
To examine the retina, the ophthalmologist will dilate the pupils using special eye drops, which will allow light to show a larger area of the retina, the macula, and the optic nerve.
In a test called fluorescein angiogram, the retina is imaged after a yellow fluorescent dye is injected to the veins to reveal better outlines of the retinal vascular structure.
What are the ophthalmologists checking for?
The ophthalmologist may check for retinal tears and red dots, which may indicate leaking blood vessels, or hemorrhages. The fluorescein angiogram can reveal signs of micro-aneurysms and vessel leakage or blockage by showing the blood flow. It will also be able to detect new blood vessel growth. An imaging test called optical coherence tomography, which measures retinal thickness, can confirm signs of macular edema. The ophthalmologist will also likely check signs of cataracts and glaucoma, the last of which is done by looking at shapes and colors of the optic nerve and cupping of the optic disk during the dilated eye exam.
What are the next steps if I am diagnosed with diabetic retinopathy?
If diabetic retinopathy has not advanced to the point of interfering with vision, the ophthalmologist may only recommend regular monitoring and lifestyle adjustments in diet and exercise to control blood sugar levels. If, however, DR is already at its advanced stage at the time of diagnosis, there are several treatment options to delay or stop its progression. Photocoagulation is a laser treatment that makes burns on the retina to stop the growth of new abnormal blood vessels. Injections of medications that inhibit the growth of vascular endothelial cells is another option. An invasive surgery, called vitrectomy, makes small cuts on the vitreous to remove blood and scar tissue. Any treatment option should be advised by certified medical providers.