Diabetic Retinopathy

Diabetic retinopathy is a disease of the eyes that affects persons with uncontrolled diabetes. Your risk of having it will increase with age and for how long you have diabetes. 

Diabetic retinopathy affects your retina. The blood vessels in it will get blocked or may start to leak. It reduces the blood supply to the retina to cause various problems. Then your retina will start making new blood vessels. These blood vessels are very fragile, and blood will start oozing out of it to create more issues.

You will have very few early symptoms. As it progresses, you will start having vision problems. Seeing black spots or floaters, blurred vision, etc., are some of the common symptoms. Gradually, these problems will get severe if you do not have treatment. Partial or complete loss of vision may happen in a few with critical issues.

To avoid this, you will have to keep your diabetes in control. You will also have control over your blood pressure and cholesterol levels. Treatments will depend on the stage and the severity of the disease.

If you have diabetes and your age is above fifty, you will need an eye test every year to rule out diabetic retinopathy. Detecting it early on will help to avoid future problems.

Causes of diabetic retinopathy

You will have diabetic retinopathy when your blood sugar levels remain high for a long time. High blood sugar will cause damage to blood vessels in all parts of the body.

Your retina is a sensitive area that needs an uninterrupted blood supply. Blocks in the arteries and veins in it can cause various problems. Due to diabetes, the blood vessels in your retina gets very weak. There will be small blood-filled bulges on its walls. These bulges may burst to ooze blood into the retina to cause problems with vision. 

At the same time, the retina does not get enough blood to nourish it. The retina then starts to grow a network of new blood vessels to compensate for the lack of blood supply. Again these blood vessels also get weak ti spill more blood out to make the problem severe.

With time scars start to form on the retina and the eyewall. These scars slowly separate the retina and the eyewall to cause 'retinal detachment.'     

Risk factors of diabetic retinopathy

As you know, diabetic retinopathy occurs in those with diabetes. But not everybody with diabetes will have this problem. There are some other factors also that may increase your chance of it. 

The risk factors include

• Having diabetes- As said, not everyone with diabetes gets retinopathy. Your chances will depend on
• For how long you have diabetes- If you had the problem at a younger age your chances are more
• How well you have controlled it- If you have been able to control the disease within limits, your chances are less.

Other risk factors include

• High blood pressure- Higher your BP, higher your chance
• High cholesterol - Cholesterol plaques that form in the walls of blood vessels can make it narrow.
• Being pregnant- Your risk is more due to hormonal changes 
• Being a smoker- Those who smoke are more at risk

Stages of diabetic retinopathy

Stage 1 Background retinopathy

You will have small bulges in the blood vessels of the retina that leak small amounts of blood.You will not have any symptoms at this stage. You will not need any treatment at this stage. Keeping your diabetes, and other risk factors under control will help to prevent further problems.

Only one in four progress to the next stage

Stage 2 Preproliferative retinopathy

• You will have a lot of changes in the retina, along with bleeding into it.
• Symptoms like blurring, floaters, etc. will start showing
• You will have eye checks every 3 to 6 months to know the progress
• Treatments will include medicines and laser therapy

Stage 3 Proliferative retinopathy

• Your retina will have a network of several small blood vessels that cause a lot of bleeding.
• The symptoms will be severe, and you will have problems with vision
• You will have various treatments to stabilize your condition. But it will be difficult to restore the vision you have lost.
• You will have scars in the retina that may detach it from the eyewall.

Stage 4 Diabetic maculopathy

• You will have severe problems in the macula, the central part of the retina
• The blood vessels in the area may be completely blocked or leaky
• Your symptoms will be severe, and you will need immediate treatment
• It will be difficult to restore any vision that you have lost

Symptoms of diabetic retinopathy

In the early stages, you will have no symptoms. It will start showing as the disease progress to advanced stages. Almost all the signs are due to the leakage of blood into the retina.

Some of the common late symptoms are

• Blurring of vision
• Seeing 'floaters' in your vision field
• Dark patches or streaks that distort vision
• Problems with night vision or seeing in the dark
• Impaired color vision
• Total loss of vision
• Sudden loss of vision

Your symptoms will get worse as the disease progresses. In some loss of vision will be the only one.

Complications of diabetic retinopathy

• Vitreous hemorrhage:  It occurs when the new blood vessels rupture and leaks blood into the vitreous humor. It will prevent light from reaching the retina. Vision problems, photophobia, etc. are common signs. In most, the problems will resolve without treatment.
• Retinal detachment- It occurs when scars pull the retina away from the eyeball as it contracts. The early symptoms will be floaters, flashes, etc. Total loss of sight may occur if you do not have any treatment.
• Glaucoma- As new blood vessels form in the eyes, there will be blocks to the flow of aqueous humor. It may increase the pressure in the eyes to cause glaucoma.

Diagnosis of diabetic retinopathy

Diabetic retinopathy will have very few early symptoms. So an ideal way to know it early is to have eye tests regularly. Some of the common tests to diagnose it early are

• Dilated eye exam: During this, your doctor will put eye drops to dilate your pupil. The doctor will then use a microscope to see the inside of your eyes. With this, the doctor will be able to detect
• Changes in the retina: Changes in the blood vessels or optic nerve
• Presence of new blood vessels
• Scars in the retina
• Any detachment of the retina:It also will show any change in IOP, cataracts, etc. Some persons will have small reactions to the drops, which will go away after some time.
• Fluorescein angiography: This test will give the doctor an idea about the blood flow in the eyes. You will have eye drops to dilate the pupils. Then the doctor will inject a dye through a vein in your arm. The dye will slowly flow along with the blood to the retina.Your doctor will be able to see any blocks, leaks, or ruptures in the blood vessels. The doctor will then be able to plan the treatment by looking into your condition. For a day or two, there will be a small yellow tinge to your skin due to the dye. Your urine will also have a dark orange color till the dye moves out of your body
• Optical coherence tomography (OCT): It is a scan of your retina to look for any issues. Any problems with the optic nerve will also show in the scan. You will have this test after treatment as well to know the effects.

Treatments for diabetic retinopathy

Intravitreal injection: 

In this procedure, the doctor will inject the medicine into your eye. The whole procedure takes about 30 minutes. You will not feel any pain, but may feel some pressure in the eye. 

Photocoagulation or Focal laser treatment: 

You will have this as an outpatient procedure. The doctor will use laser beams to close and seal any leaks in the blood vessels. It thus prevents or slows down the oozing out of the blood. It also helps to relieve the pressure in the eyes and further scars from forming in the retina.

Some will have mild irritation or pain in the eyes for some time. There will also be some blurring. Seeing dark spots is another problem. All these will go off after a day or two.

Pan-retinal coagulation or scattered laser treatment:

It helps to shrink the new blood vessels that form in the retina. The doctors will apply laser on the areas away from the macula, the central part of the retina. 

You will need three to four sessions to complete the treatment. The blurring of vision may happen for a day or two. In a few, there will be some loss of peripheral vision as well as night vision.

Vitrectomy

It is a small surgical procedure to remove the vitreous humor along with the blood clots in it. The doctor will also remove any scar tissue that puts pressure on the retina. You will have a small cut in the eyeball to remove the fluid.

The new vitreous that forms will be clear and will help improve your symptoms. You will have the procedure under local or general anesthesia.

How to prevent diabetic retinopathy?

There are many steps you can take to prevent diabetic retinopathy. 

• Keep your blood sugar under control
• Keep your blood pressure and cholesterol levels within limits
• Get regular eye tests
• Stop smoking
• Drink alcohol only in moderation

Women with diabetes who get pregnant will need tests to detect any changes in the blood vessels in the retina