Diabetic retinopathy is the most common diabetic eye disease associated with type 1 or 2 diabetes. Diabetic retinopathy damages the blood vessels within the retina, causing them bleed and leak fluid. These leaking vessels often lead to swelling (macular edema) in the retina. In early stages, vision may start to blur.
As retinopathy advances, parts of the retina will begin to die as blood vessels become blocked or closed. This causes the growth of new, abnormal blood vessels on the surface of the retina, which bleed easily, causing the appearance of floaters – which resemble small dark spots that drift in the field of vision – along with a further decrease in vision. Diabetic retinopathy usually affects both eyes and as it progresses, leads to increased the risk of retinal detachment, glaucoma, and possibly blindness.
This disease is one of the leading causes of blindness in Canada due to difficulty controlling sugars, blood pressures, and missed screening opportunities.
Symptoms of Diabetic Retinopathy
The symptoms of diabetic retinopathy vary depending on the stage of the disease.
In early to intermediate stages, common symptoms of diabetic retinopathy include:
- Blurred vision
- Sudden, painless loss of vision
- Reduced perception of colours
- Dark, blotchy, or empty areas in your vision
- Appearance of floaters which resemble dark spots or pieces of dust in your frontal vision
As the damage caused by diabetic retinopathy progresses, it can cause sudden, severely loss of vision or blindness with minimal warning signs or symptoms.
Causes of Diabetic Retinopathy
Diabetic retinopathy is caused by poorly controlled blood sugars and blood pressure as a result of diabetes. Over time, high blood sugar and high blood pressure cause damage to the blood vessels that provide the retina with oxygen, nutrients, and fresh cells. This creates blockages that prevent blood from reaching the retina. This causes vision loss.
Without a regular, healthy flow of blood, the eye will attempt to grow new blood vessels, however, these are abnormal and prone to hemorrhaging and to leaking fluids. Scar tissue may also form which pulls on the retina and results in retinal detachment.
As this condition persists, vision loss becomes increasingly more severe and can ultimately result in blindness.
Diagnosing Diabetic Retinopathy
Diabetic retinopathy is diagnosed through a dilated eye exam and slit-lamp examination.
Additional tests may be required to verify if there are any signs of damage. Further testing helps ensure that your retinal specialist can provide the most effective treatment and monitor any risks that diabetic retinopathy may pose to your vision. These tests include a fluorescein angiography and ultrasound tests if a vitreous hemorrhage has begun to occur. The fluorescein angiography test is needed to evaluate the condition of the retina, the formation of abnormal blood vessels, and any bleeding or leakage that may be occurring.If a blood vessel has already ruptured and begun bleeding within the vitreous cavity, an ultrasound examination will allow your retinal specialist to examine the retina and determine if it has been detached. If a detachment has occurred, surgery will be needed promptly.
Adults diagnosed with diabetes are recommended to schedule eye exams at least once a year. Children or teenagers newly diagnosed with diabetes need to discuss with their family doctor or endocrinologist the appropriate timing of their first diabetic eye examination. If diabetic eye disease is detected, your retinal specialist will likely recommend that you return for testing every 6 to 12 months in order to screen for risks.
Patients with a longer history of diabetes and poorly controlled blood sugars or blood pressure are more likely to develop diabetic retinopathy and will need more frequent monitoring exams.
Treatment ofDiabetic Retinopathy
Treatment of diabetic retinopathy varies depending on the severity of the case and whether any damage has already begun to occur. Some patients may require a combination of treatments to control the formation of abnormal blood vessels, reduce macular edema / swelling, and prevent vision loss.
Brief summaries of the treatments for diabetic retinopathy are outlined below. Please click upon the name to be redirected to a page with a complete description of the treatment and recovery.
Panretinal Photocoagulation Laser Treatment:This laser treatment is used to control bleeding caused by abnormal blood vessels. During panretinal photocoagulation laser treatment, a series of small, painless burns are made to the retina. This causes the abnormal blood vessels to regress.
Avastin or Lucentis Injections:Avastin and Lucentis are anti-VEGF medications that are intravitreal injected into the eye. These medications block the chemical responsible for the growth of abnormal blood vessels and for leakage from blood vesselsin cases of diabetic retinopathy. Avastin and Lucentis help mitigate the risk of vision loss caused by fluids leaking from the blood vessels.
Vitrectomy Surgery: A vitrectomy is a specialized procedure used in cases where diabetic retinopathy has caused vitreous hemorrhages and/or retinal detachment. During vitrectomy surgery, very small, precise are made into the sclera of the eye, so that blood and scar tissue caused by the abnormal blood vessels can be removed. This prevents further vitreous hemorrhages and allows light to pass through to the retina. To help reattach the retina and allow it to heal in place, a small gas or oil bubble is placed into the vitreous space so that the retina is placed back into the correct position.
If diabetes is well controlled and eye examinations are scheduled appropriately, patients can enjoy a lifetime of good vision.