Diabetic Related Eye Diseases
Diabetic patients experience many health complications arising from impaired blood sugar control, one of which is damage to the membrane at the back of the eye responsible for receiving visual images (the retina). Retinal damage is common in patients with diabetes and may have a progressive and debilitating impact on vision, eventually leading to blindness without treatment. The longer a person has diabetes, the higher their chances of developing diabetic retinopathy.
The retina is a layer of light-sensitive tissue at the back of the eye. As light enters the eye, through the cornea and the lens, it is then focussed onto the retina. The retina sends nerve impulses along the optic nerve and into the brain where it is interpreted as an imagine. In people with diabetes, tiny blood vessels in the retina may become diseased and damaged. Diabetic Retinopathy usually affects the retina slowly.
Diabetes can cause the blood vessels to swell and leak blood or fluid around the retina. The healing process forms scar tissue. These problems can damage the retina so badly that the retina functions less effectively and vision is impaired. The area of the retina that provides the sharpest vision is called the macula. Leaking blood or fluid can cause the macular to swell. This causes blurred vision and is a common result of diabetic retinopathy.
Other eye disease:
People with diabetes have a higher risk of developing other eye diseases. For example, the risk of developing glaucoma or a cataract in either eye is twice that of a non-diabetic person.
Symptoms:
As the condition progresses you might develop:
- Spots or dark strings floating in your vision (Floaters)
- Blurred vision
- Fluctuating vision
- Dark or empty areas in your vision
- Vision loss
Diagnosis:
Fluorescein Angiography– once your eyes are dilated, a dye is injected into a vein in your arm. Pictures are then taken as the dye circulates through your eyes blood vessels. The images can pinpoint blood vessels that are closed, broken or leaking.
Optical Coherence Tomography (OCT)- Pictures provide cross-sectional images of the retina that show the thickness of the retina. This will help determine how much fluid, if any, has leaked into the retinal tissue. OCT exams can be used to monitor how treatment is working.
Treatment:
Treatment is very depended on the type of diabetic retinopathy you have and how severe it is;
Early Diabetic Retinopathy – Treatment might not be required right away but your doctor will closely monitor your eyes to determine when you might need treatment.
Advanced diabetic retinopathy – Options might include:
- Injecting medications into the eye (Ranibizumab (Lucentis), Aflibercept (Eylea), Bevacizumab (Avastin) – Vascular endothelial growth factor inhibitors are injected into the vitreous of the eye. They help stop growth of new blood vessels and decreased fluid build-up.
These drugs are injected using topical anaesthesia, Injections can cause mild discomfort, such as burning, tearing or pain for 24 hours after the injection. These injections will need to be repeated.
- Photocoagulation – This laser treatment can stop or slow the leakage of blood and fluid in the eye. During the procedure, leaks from abnormal blood vessels are treated with laser burns.
- Vitrectomy – Tiny cuts are made in the sclera (white of eye). Special instruments and bright fibreoptic light are then inserted into the vitreous cavity. Vitreous contaminated with blood is removed with a hand-held cutting device and replaced with a clear salt solution similar to the liquid removed from the eye. In some cases a special synthetic gas or silicone oil may be applied inside the eye. Over time this is absorbed and slowly replaced by fluid produced by the eye.
While treatment can slow or stop the progression of diabetic retinopathy, its not a cure. Diabetes is a lifelong condition, future retinal damage and vision loss are still possible.