Understanding Diabetic Eye Disease
Diabetic eye disease is a complication of long-standing or poorly controlled diabetes. High blood sugar damages small blood vessels throughout the body. When small blood vessels are damaged in the retina (nerve layer) of the eye, patches of bleeding and leakage of proteins or fat occur within the retina, resulting in visual loss.
Diabetic eye disease takes many years to develop. This means that there are many opportunities for early stages to be picked up and treated before they reach the later stages.
Once retinopathy sets in, it indicates that significant damage has accumulated within blood vessels in the body. Therefore, it is possible that the kidneys, heart and small nerve endings of the fingers and toes are also already affected.
Causes
Symptoms
Types of Diabetic Retinopathy and Maculopathy
Diabetic maculopathy (macular edema).
Scan of the macula shows severe swelling.
Advanced diabetic retinopathy with severe bleeding in the eye.
Diabetic Eye Screening
All diabetics are recommended to undergo regular eye examinations to pick up diabetic retinopathy early. Even in the absence of symptoms, eye examinations should be done at least once a year as there may be no symptoms in the early stages of retinopathy.
Those already diagnosed with diabetic retinopathy may need to be monitored more frequently as early treatment is critical for a favorable outcome.
The minimum eye screening involves having a photograph taken of the retina (diabetic retinopathy photo screening). A detailed eye examination is recommended for those at higher risk of diabetic retinopathy or those not suitable for photo screening.
If diabetic retinopathy or maculopathy is detected on basic photoscreening, further tests such as “OCT” scans may be ordered to assess the extent of the damage and a detailed eye examination by an eye doctor is recommended.
Diabetic Retinopathy Treatment Options
Intravitreal Injection Therapy: The gold standard treatment for diabetic macular edema involves injecting medications directly into the eye. These medications reduce fluid leakage and reduce the risk of permanent loss of vision.
These medications are also useful for advanced-stage diabetic retinopathy to prevent severe bleeding in the eye.
Many anti-VEGF medications are now available. Lucentis (ranibizumab), Eylea (aflibercept), and the newest medication Vabysmo (faricimab) are all effective provided treatment is started early. Apart from anti-VEGF agents, sustained-release steroids (Ozurdex) have also been proven to work well.
Laser Therapy: In some cases, laser therapy may be used either on its own or in conjunction with intravitreal injections to target and seal abnormal blood vessels, further stabilizing vision and preventing disease progression.
Surgery: In severe cases with bleeding within the eye or where retinal detachments have already occurred, surgery (vitrectomy) may be necessary to avert severe and permanent visual loss or blindnes.
FAQs
The longer the duration of diabetes, the higher the risk of having diabetic eye disease. In general, risks go up in those with longer duration (more than 5 years) of diabetes, especially if sugar control has been unsatisfactory.
The risk is also higher in individuals who have other medical conditions like hypertension and “high cholesterol” levels. Diabetics who are pregnant are also at increased risk.
Regular eye screening is important for all diabetics but even more so in the presence of these risk factors.
No eye-specific treatment is necessary for early diabetic retinopathy because the most effective treatment is good control of blood sugar levels with proper diet and diabetic medication. Controlling blood sugar (and other medical conditions like hypertension and “high cholesterol”) will slow down the worsening of retinopathy, and may even reverse some very early changes.
Eye treatments like laser, eye injections and surgery are usually recommended when retinopathy reaches specific stages when the benefits of treatment outweigh the risks. There are currently no eyedrops effective for diabetic retinopathy.
Laser is usually done for advanced diabetic retinopathy. The objective is to limit visual loss or prevent blindness. Improvement in vision may not occur as irreversible damage is often already present at the late stages of the disease.
In individuals in whom vision is impaired by macular edema, intravitreal anti-VEGF and steroid injections may be able to improve vision.