Did you know diabetes affects the Eye?
If you have diabetes mellitus, your body does not use and store sugar properly.
High blood-sugar levels can damage blood vessels in the Retina. Retina is the nerve layer at the back of the Eye that senses light and helps to send images to the brain.
The damage to Retinal blood vessels is called diabetic retinopathy. Diabetes also causes diseases like Cataract and Glaucoma in the Eye. Retina is a thin sheet of nerve fibres in the back portion of the Eye. The Picture we see first falls on the retina and then it is transmitted to The brain, via the Optic nerve. Macula is the center of the retina and is an area responsible for fine vision, Like reading, writing.
Diabetic retinopathy is of 3 Types:
1. Nonproliferative diabetic retinopathy (NPDR)
Commonly known as background retinopathy, it is an early stage of diabetic retinopathy.In this stage, tiny blood vessels within the retina leak blood or fluid. The leaking fluid causes the retina to swell or to form Deposits called exudates.
Many People with diabetes have mild NPDR, which usually does not Affect their vision.When vision is affected it is the result of Macular Edema (swelling) and/or macular ischemia (improper blood Supply).
Therefore a regular retinal check-up is necessary for all diabetics to detect the early changes.
2. Proliferative diabetic retinopathy (PDR)
This is present when abnormal new vessels (neovascularization) begin growing on the surface of the retina or optic nerve.
The main cause of PDR is widespread closure of retinal blood vessels, preventing adequate blood flow.The Retina responds by growing new blood vessels in an attempt to supply blood to the area where the original vessels closed.
Unfortunately, the new, abnormal blood vessels do not resupply the retina with normal blood flow. They are fragile and may cause bleeding in the Retina.
Scar Tissue that may cause wrinkling or detachment of the retina often accompanies the New Vessels.
PDR may cause more severe vision loss than NPDR because it can affect both central and peripheral vision.
Proliferative diabetic retinopathy causes visual loss in the following ways:
- Vitreous hemorrhage (bleeding):
The fragile new vessels may bleed into the vitreous, a clear, gel like substance that fills the center of the eye. If the vitreous hemorrhage is small, a Person might see only a few new dark floaters. A very large haemorrhage might block out all vision.
It may take days, months, or even years to resorb the blood, depending on the amount of blood present. If the eye does not clear the vitreous blood adequately within a reasonable time, vitrectomy Surgery may be recommended.
Vitreous hemorrhage alone does not cause permanent vision loss. When the blood clears, vision may return to its former level unless the macula is damaged.
- Tractional retinal detachment:
When PDR is present, scar tissue associated with neovascularization can shrink, wrinkling and pulling the retina from its normal position. Macular wrinkling can cause visual distortion. More severe vision loss can occur if the macula or large areas of the Retina are detached.
Neovascular Glaucoma :
Occasionally, extensive retinal vessel closure will cause new, abnormal blood vessels to grow on the iris (Colored part of the Eye) and block the normal flow of fluid out of the Eye. Pressure in the Eye builds up, resulting in neovascular glaucoma, a severe eye disease that causes damage to the optic nerve.
3. Diabetic maculopathy – Clinically significant macular oedema (CSME)
In diabetic maculopathy, fluid rich in fat and cholesterol leaks out of damaged vessels. If the fluid accumulates near the center of the retina (the macula) there will be distortion of central vision.
If too much fluid and cholesterol accumulates in the macula, it can cause permanent loss of central vision. CSME (Clinically Significant Macular Oedema) is the term given to describe water logging of the macular area .The Swelling is the most common cause of visual loss in diabetics. Most Patients with CSME need laser. Your eye care provider can see this when he/she examines your eye.
Diabetic maculopathy requires treatment if fluid is leaking into the macula. The treatment begins with identifying the leaking blood vessels on the fluorescein angiogram.
Laser treatment can be applied to seal the leaking vessels. The laser is an intense beam of light, which can be finely focused on each individual leak.
Laser is effective in stabilizing or improving vision in 75% of patients with macular edema. Despite treatment, 25% of patients continue to lose vision due to recurring leaks. Control of diabetes and blood pressure is important in reducing the chances of leaking vessels returning following treatment. The fluid often takes up to 2 to 3 months to dry up following closure of abnormal vessels.
Visual recovery is slow and gradual. If the fluid persists, the fluorescein angiogram is repeated to determine the site of the vessels still leaking and laser treatment may be repeated. The average patient needs 2-3 laser sessions per eye to control diabetic maculopathy over the course of their lifetime.
Some frequently asked questions about Diabetic Retinopathy :
How is diabetic retinopathy diagnosed?
A medical eye examination is the only way to detect changes inside your eye. An ophthalmologist can often diagnose and treat serious retinopathy before you aware of any vision problems. The ophthalmologist dilates your pupil and looks inside the eye with an indirect ophthalmoscope.
If your ophthalmologist finds diabetic retinopathy, he or she may order colour photographs of the retina or a special test called fluorescein angiography to find out if you need treatment. In this test a dye is injected into your arm and photos of your eye are taken to detect where fluid is leaking.
How is diabetic retinopathy treated?
The best treatment is to prevent the development of retinopathy as much as possible. Strict control of your blood sugar and kindly problems are present, they need to be treated.
- Laser Surgery:
Laser surgery is often recommended for people with macular edema and proliferative diabetic retinopathy.
For macular edema, the laser is focused on the damaged retina near the macula to decrease the fluid leakage. The main goal of treatment is to prevent further loss of vision. It is uncommon for people who have blurred vision from macular edema to recover normal vision, although some may experience partial improvement. A few people may see the laser spots near the center of their vision following treatment. The spots usually fade with time but may not disappear.
In PDR, the laser is focused on all parts of the retina except the Macula. This panretinal photocoagulation (PRP) treatment causes abnormal new vessels to shrink and often prevents them from growing in the future. It also decreases the chances that vitreous bleeding or retinal distortion will occur.
Multiple laser treatments over time are sometimes necessary. Laser Surgery does not cure diabetic retinopathy and does not always prevent further loss of vision.
In advanced PDR, the ophthalmologist may recommend a surgery known as vitrectomy.During this microsurgical procedure, which is performed in the operating room, the procedure, which is performed in the operating room, the blood filled vitreous is removed and replaced with a clear solution. The ophthalmologist may wait for several months or up to a year to see if the blood clears on its own before performing a vitrectomy.
Vitrectomy often prevents further bleeding by removing the abnormal vessels that caused the bleeding. If the retina is detached, it can be repaired during the vitrectomy surgery. Surgery should usually be done early because macular distortion or traction retinal detachment will cause permanent visual loss. The longer the macula is distorted or out of place, the more serious the vision loss will be.
Is Vision Loss Is Preventable?
Yes, Vision Loss Is Largely Preventable!
If you have diabetes, it is important to know that today, with improved to know that today, with improved methods of diagnosis and treatment, only a small percentage of people who develop retinopathy have serious vision problems. Early detection of diabetic retinopathy is the best protection against loss of vision.
You can significantly lower your risk of vision loss by maintaining strict control of your blood sugar and visiting your ophthalmologist regularly.
When to Schedule an Examination?
People with diabetes should schedule examinations at least once a tear. More Frequent medical eye examinations may be necessary after a diagnosis of diabetic retinopathy.
Pregnant women with diabetes should schedule an appointment in the first trimester because retinopathy can progress quickly during pregnancy.
If you need to be examined for eyeglasses, it is important that your blood sugar be consistently under control for several days when you see your ophthalmologist. Eyeglasses that work well when the blood sugar is stable.
Rapid changes in blood sugar can cause fluctuating vision in both eyes even if retinopathy is not present.
You should have your eyes checked promptly if you have visual changes that:
- Affect only one Eye
- Last more than a few days
- Are not associated with a change in blood sugar
- When you are first diagnosed with diabetes, you should have your eyes checked 😐
Within five years of the diagnosis if you are 29 years old or younger;
Within a few months of the diagnosis if you are 30 years old and older.