The excessive levels of glucose in the blood gradually damages the blood vessels themselves. The walls of blood vessels become weak, leaky, ballooned. This is the Nonproliferative stage (NPDR)

Early milder NPDR changes in Retina

As the disease progresses, some of the blood vessels get blocked depriving the retina of important nourishment. This starts the process of proliferative phase or PDR.

More severe damage due to diabetes 

Damaged blood vessels can leak fluid into the most essential central part of the retina (macula) causing it to swell resulting in blurred vision. This condition called Macular Edema (CSME) can occur at any stage of diabetic retinopathy, although it is more likely to occur as the disease progresses.

Proliferative phase (PDR) involves development of abnormal fragile blood on the retina. These fragile vessels can bleed inside the eye (vitreous hemorrhage) and even pull the retina out of its normal position (Tractional retinal detachment) causing severe vision loss.

Symptoms are NOT reliable indicators of onset of disease and should not be relied on to seek medical care. These are unusual in the early stages of the disease and often appear in the late stages without warning signs.

It is important NOT to wait for symptoms to get an eye exam. A comprehensive eye test is a MUST for all diabetic patients at least once a year.

Later in the disease, diabetic retinopathy symptoms may include:

• Spots floating in vision.
• Blurred vision.
• Dark streaks or a red film that blocks the vision.
• Poor night vision.
• Vision loss.

Early detection of diabetic retinopathy is the key to prevent severe vision loss. If you have diabetes, see your eye doctor for an yearly dilated eye exam even if there are no symptoms.

Your doctor may ask for more frequent checkups in case of you have more advanced disease. If you become pregnant, you may require additional eye exams throughout your pregnancy.

Contact your eye doctor immediately if you have sudden vision changes or your vision becomes blurry, spotty or hazy.

Diabetic retinopathy is best diagnosed with a dilated eye exam. During the exam, your eye doctor will first dilate your pupils with eye drops. This may cause blurring of your close-up vision for several hours. Make sure you have somebody to take you back home as you won’t be able to drive for a few hours.

Your eye doctor will use a special magnifying lens to examine the inside of your eye for signs of damage. If your eye doctor finds features of retinopathy, he or she may suggest further investigations such as fluorescein angiography or OCT for evaluation.

This process uses special non-mydriatic fundus cameras to allow screening for diabetic retinopathy without the cumbersome process of dilatation. These cameras can capture detailed photo of the retina without the time consuming process of dilatation. 

Do check with your doctor for this facility if u want to save time and effort

Fluorescein Angiography is a test to assess the damage to retinal blood vessels. It is done by injecting fluorescein dye into the arm followed by use of a special camera to take multiple digital photographs of the retina. The test allows the doctor to see areas of leaking and blocked blood vessels. This allows correct grading of the disease and helps further management.

OCT (Optical Coherence Tomography) is a non-invasive test which uses laser to assess the retina at microscopic level. It can be used to detect and measure areas of retinal swelling and allows non-invasive monitoring of the disease activity.

Laser treatment is required when the eye has Macular Edema (CSME) or PDR (Proliferative Diabetic Retinopathy). This treatment has been conclusively shown to reduce the chances of further vision loss.

It is an OPD procedure and takes around 10-15 min. In some cases multiple sittings may be required to complete the laser. Before laser treatment eye drops are instilled to dilate the pupils and numb the eye. A special lens is applied on the eye and laser treatment done. During the procedure, the patient may see flashes of light. The procedure causes only minimal discomfort and does not require any special postoperative care. Since the eyes are dilated, it is important that the patient has somebody to drive him back as the vision is likely to be little blurry for the rest of the day. Having a pair of sunglasses can also help.

Laser treatment has been conclusively proven to reduce the chances of further vision loss. It may not be able to restore vision, hence the need for screening and early treatment.

• For Macular Edema (swelling in the central retina) the laser treatment involves placing few hundred small laser burns in that area. In some cases more than one treatment may be required to control the leakage.
• For PDR (proliferative disease) 1,000 to 2,000 laser burns are applied in the peripheral retina. 3-4 sessions may be required due to the large number of spots.

Side effects of laser treatment can include some loss of your side and peripheral  vision and reduction of color and night vision. But these effects are minor compared to the effect of NOT doing the laser and it can save the rest of your sight.

For many decades, laser treatment was the only treatment available for people with  diabetic retinopathy. And then approximately 15 years ago, it was noticed that a new class of drugs (even though intended for cancer treatment) was also helpful in this disease.

VEGF is a protein in the eye which has been found to play a central role in the development of diabetic retinopathy. These new drugs inhibited this chemical to control diabetic retinopathy. These drugs Bevacizumab (Avastin), Ranibizumab (Lucentis / Accentrix / Razumab), Aflibercept (Eyelea) were found to be very effective in treatment of diabetic retinopathy especially cases which were resistant to laser treatment. However these drugs are required to be injected directly into the eye and the effect is relatively short lived.

Inspite of these limitations, the role of these injections have drastically increased over the last decade or so. These have nicely complemented laser  treatment and even replaced it in some cases.

The answer to that question is both no and yes.

Diabetes is an ongoing disease and so is diabetic retinopathy. No laser or injection treatment can ensure that the patient will not require any further treatment. Hence the need for long term followups.

With laser treatment, the probability of need of repeat treatment is less compared to injections. However injections are more effective. Hence the need to use both treatments to balance the side effects of each and to complement each other. And in most cases multiple injections may not be required

Surgery is required only in some patients when the disease becomes advanced thus causing bleeding in the eye or detachment of retina. This results in significant loss of vision and in some cases blindness.

These are retinal surgeries that involve removal of vitreous (the clear jelly that fills almost 80% of the eye).

This may be required in advanced cases of diabetic retinopathy when there is bleeding in the eye or the retina gets detached causing loss of vision.

It is performed under local or general anesthesia wherein the surgeon uses a thin probe to enter the eye and remove the clouded vitreous gel. The procedure takes anything between 30 min to 1 hour and can be done as a daycare procedure. With advancement in technology, it has become a sutureless procedure with fast recovery.

Prevention is better than cure

• Monitor and control blood sugar tightly. Keeping blood sugar levels close to normal slows the progression of disease and reduces the need for any kind of treatment for this disease.
• Keep blood pressure and cholesterol under control.
• Maintain normal haemoglobin
• Stop smoking or the use of any form of tobacco.
• Yearly dilated eye exams are absolutely essential as early warning signs are typically absent. Even patients with most severe forms of retinopathy may not have any symptoms.
• Contact your eye doctor immediately if you notice sudden vision changes or your vision becomes blurry, spotty or hazy.