How does diabetes affect sight?
Diabetes leads to abnormality of the blood vessels in the body. The blood vessels in the retina are also affected. The affected blood vessel leaks fluid, blood, and lipids (fats) in the retina.
What are the types?
1. Diabetic maculopathy
2. Proliferative diabetic retinopathy
What is diabetic maculopathy?
When the central part of the retina (macula) is affected, it leads to the inability of the eye to see clearly. This is due to accumulation of fluid, blood and lipids. In the initial stages, patients may not have any symptoms, but with progression, and the swelling becoming worse, it leads to distorted and poor eyesight. Untreated, it can lead to partial sightedness or blindness.
How is diabetic maculopathy treated?
This can be treated either by laser or injecting medicine into the eye.
1. Sometimes, in mild cases a good control of blood sugar can reduce the swelling without any treatment. If it is significant, then it can be treated with laser, or drugs (Medication) injected into the eye. The laser is a straightforward outpatient procedure, which takes about 10-15 minutes to perform. The laser produces heat energy and helps stops the blood vessels from leaking.
2. Drugs: There are two groups of drugs, one is called anti-VEGF, and the second, steroid implants. This drug is injected monthly for 3 to 5 months and then injected bimonthly or when scan shows the need for more injections. The Anti-VEGF drugs on an average will need 7-8 injections in the first year, and this reduces to 3 injections in the second year, with further reduction in subsequent years. The steroid implants need not be injected monthly. They last longer. For example, Dexamethasone implant (Ozurdex) may need to be injected on an average three times a year, whereas, Fluocinolone implant (Iluvien) is injectedonly once and this may last for 2-3 years.
Can I choose one from the various options?
Not always, you may not be suitable for certain treatment options. This will depend on your eye condition and general health status. Your treating doctor will discuss and suggest the best treatment option for your circumstance.
What is proliferative diabetic retinopathy?
This is a more serious diabetic eye condition. Diabetic patients develop this if they had neglected their sugar control for too long. In this condition abnormal and fragile blood vessel grow on the surface of the retina called as neovascularization (new vessels). Due to their fragility, they are prone to bleed on the surface of the retina or in the vitreous jelly called vitreous haemorrhage. The bleeding on the surface of the retina also causes scar tissue to develop and pull the retina, leading to retinal detachment and blindness.
What are the treatment options for proliferative diabetic retinopathy?
When the new vessels are detected before they bleed, they can be treated by laser. They usually respond well to treatment. If they bleed into the vitreous cavity, they can be treated by vitrectomy surgery, where the vitreous gel is removed along with the blood. If the scar tissue pulls the retina away, then they need complex retinal surgery. The risk for developing sight impairment or blindness is very high should this happen.
Useful websites : www.diabetes.org.uk
For research reference : www. macular society.org/references