Can Diabetes Cause Blindness Without Warning?

*हिंदी में पढ़ें: क्या मधुमेह बिना किसी चेतावनी के अंधापन का कारण बन सकता है?

The short answer is: Yes! Diabetes is associated with several eye conditions. Many of these may not cause noticeable symptoms in their early stages, making diagnosis difficult if the patient does not get regular eye checkups.

But the good news is that managing your blood sugar levels, blood pressure, and cholesterol, and getting routine eye assessments can help delay or even prevent diabetic eye conditions. 

Regular eye examinations can help detect eye issues in time so that you can get your eyes treated and save your sight. 

👉 Did you know? The retina is the light-sensitive layer at the back of the eye that converts light into electrical signals. The optic nerve sends these signals to the brain, which interprets them to create vision.

How Does Diabetes Affect Eyes?

Consistently high blood sugar levels can result in various eye conditions, such as:

• Diabetic retinopathy
• Cataracts 
• Glaucoma 

If left untreated, these eye diseases can cause blurry vision, severe loss of vision, and even blindness.

Diabetic Retinopathy (DR)

Caused by diabetes, DR is one of the major reasons for vision loss in working-age adults. The condition occurs when the blood vessels in the retina of the eye get damaged as a result of high blood sugar. 

There may be swelling and leakage in the damaged blood vessels, giving rise to blurred vision. 

Diabetic retinopathy typically affects both eyes.

What are the Risk Factors for Diabetic Retinopathy?

Diabetes itself is the risk factor, be it type 1, type 2, or gestational diabetes^[1] (diabetes during pregnancy). People who have diabetes for a longer time (more than 5-10 years) are more prone to it. Other factors that raise the risk include:

• High blood sugar
• High BP
• High cholesterol 
• Smoking
• Specific ethnic groups (Hispanic/Latino, Native American/Alaska Native, African American, South Asian populations)
  

👉 Did you know? Eyes are the 2nd most complex organ in your body, second only to the brain.

What are the Stages of Diabetic Retinopathy?

Early or Nonproliferative Stage

Retinal blood vessels weaken and bulge, forming small pouches that may leak. When this happens, the macula (a part of the retina) may swell and distort vision. The condition is referred to as macular edema, and is the leading cause of vision loss in patients with diabetic retinopathy. Nearly 50 out of 100 people with DR get affected by macular edema. [via CDC^[2]]

Advanced or Proliferative Stage

New blood vessels start developing in the retina. These are delicate and bleed easily. The result is dark spots in the vision. In cases of substantial bleeding, there may be sudden and significant vision loss.

👉 Did you know? Nearly 80% of the sensory input to the human brain originates from the vision system.

What are the Symptoms of Diabetic Retinopathy?

The biggest reason why diabetes can cause blindness without any warning is the nature of DR. There may be no clear symptoms in the initial stages. However, you should be aware if you notice any of the following signs:

• Dark spots or shapes in vision
• Difficulty reading
• Blurred vision
• Difficulty seeing colours
• Dark or blank spots in vision
• Poor night vision
• Difficulty recognising faces
• Inability to see (loss of vision)
  

👉 Did you know? The retina and optic nerve in your eyes do not contain pain-sensitive nerve endings. That’s why you may have serious eye conditions, like diabetic retinopathy and glaucoma, and still be unaware of it until permanent damage occurs.

How is Diabetic Retinopathy Diagnosed?

When you visit the doctor, they will examine your distant vision. They will also conduct a detailed eye exam after dilating your eyes. This will allow them to check your retina and its blood vessels. 

If you have diabetic retinopathy, routine eye examinations are essential. The earlier you get treatment, the better its efficacy. That’s why timely diagnosis is critical even in the absence of symptoms. 

Diagnosed with type 2 diabetes? Get your eyes examined for DR without delay.

Diagnosed with type 1 diabetes? Get your eyes tested within 5 years of diagnosis. [via CDC]

Sudden vision changes? Talk to your doctor immediately if you notice:

• Dark spots
• Blurriness
• Distorted vision
• Flashes
• Floaters
• Trouble doing detail work or reading
• Sudden vision loss

👉 Did you know? More than 1 million nerves connect each eye with the brain. Wondering how? Each optic nerve contains over one million nerve fibres that carry visual information from the eye to the brain.

How is Diabetic Retinopathy (DR) Treated?

DR treatment involves repairing the eye damage and preventing blindness. However, treatment should begin before vision loss occurs. In cases of delayed treatment, the aim is to slow disease progression, preserve vision, and manage complications.

Common treatment options include:

• Laser therapy (laser photocoagulation) to seal leaking blood vessels
• Intravitreal injections to reduce swelling
• Vitrectomy (surgery) to remove blood and scar tissue
• Treatment for detached retina (if required)

👉 Did you know? The retina can detect only 3 colours: red, blue, and green. Still, we can recognise 10 million+ different colours. How? The retina contains three types of cone cells that are sensitive to red, green, and blue wavelengths, allowing us to perceive millions of colours.

Diabetes and Cataracts

The natural eye lens turns cloudy as you grow older. This is known as a cataract, and it happens to everyone. 

But those with diabetes have a higher probability of getting cataracts, and that too, at a younger age, the reason being that high sugar levels can lead to deposits building up in the eye lens, making them cloudy. 

High BP, being overweight, smoking, and excessive exposure to the sun are some other risk factors. 

How are Cataracts Treated?

The only treatment for cataracts is surgery. But most people do not generally require surgery unless cataracts and the accompanying loss of vision start interfering with routine activities. Most patients regain better vision after surgery. 

The good news is that today, there are advanced options in cataract surgery, such as MICS, FLACS, and Advanced 4D Phaco. These involve no injection, no stitches, and no pain. You can even go home the same day.

What to do in the meantime? Use brighter lighting at home and anti-glare sunglasses when outside.  

👉 Did you know? The retina comprises 2 types of nerves: rods and cones. Rods enable night vision and allow you to see shapes, while cones give you sharp vision and help identify colours.

Diabetes and Glaucoma

Glaucoma is the name given to a group of eye diseases that silently harm the optic nerve. It generally happens due to excessive pressure in the eye, although it can also occur with normal eye pressure. Several glaucoma types have no early symptoms, and vision is lost very slowly.

Diabetic individuals are 2X more likely^[3] to suffer from open-angle glaucoma (the most common type). 

You may be at higher risk if: 

• There’s a family history
• Age is above 60
• Ethnicity is Asian, African American, or Hispanic/Latino

Neovascular glaucoma may also develop because of diabetes, along with DR. New and fragile blood vessels come up on the iris (coloured part of the eye), not letting the eye fluid flow out of the eye. This results in an increase in eye pressure.  

While glaucoma cannot always be prevented, timely treatment can stop it from worsening. This is the reason why early glaucoma detection is crucial. 

How is Glaucoma Treated?

There are several advanced treatment options for glaucoma, including:

• Medications in the form of eye drops and oral medicines
• Different laser treatments (SLT, YAG PI, cyclophotocoagulation, etc.)
• Surgery (trabeculectomy, GDDs, MIGS, etc.)

Your doctor will suggest which treatment will be suitable for you.  

👉 Did you know? The ‘red eye’ you see in flash photography is because of the retina being densely packed with blood vessels.

Can You Delay or Prevent Diabetic Eye Diseases?

You can take some precautionary measures to safeguard your vision:

• Get annual comprehensive dilated eye assessments for early detection of any eye issues 
• Keep your blood sugar levels within the prescribed limits
• Regulate your blood pressure
• Keep your cholesterol under check
• Eat a healthy, balanced diet
• Refrain from smoking
• Exercise regularly

Conclusion

Diabetes is a serious lifestyle disease that can affect multiple organs in your body, and your eyes are one of them. And yes, diabetes can cause blindness without any warning. It happens if diabetic eye disease develops unnoticed and remains untreated, as early stages often have no noticeable symptoms.

Diabetes can have several implications for the eyes, with diabetic retinopathy being a major cause of blindness among working-age adults. Those with diabetes are also more vulnerable to cataracts and glaucoma, with glaucoma being known as ‘the silent thief of sight’. Just like diabetic retinopathy, glaucoma may have no early symptoms. 

The best protection against diabetes-related eye issues is getting regular eye checkups, at least once a year. This allows the experienced eye doctors to detect and treat any eye conditions early. 

Sohana Hospital, Mohali, has cutting-edge eye diagnostics and treatments for all kinds of eye diseases. Dedicated and compassionate doctors follow a patient-centric approach for every patient, with the single goal of restoring clear vision and allowing you to see clearly.

Timely Diagnosis = Best Protection Against Diabetic Eye Diseases

Frequently Asked Questions – Diabetes & Blindness

1. Can diabetes affect my eyes even if my sugar is under control?

Yes. Controlled blood sugar lowers the risk, but you must still undergo regular eye exams since diabetic retinopathy may not have any symptoms in the early stage.

2. Does every diabetic patient develop diabetic retinopathy?

No. But all diabetics are at risk, particularly if blood sugar remains consistently high for a long time. Regular eye tests can help identify problems early and save vision.

3. Can diabetic retinopathy cause permanent blindness?

If not treated in time, DR can result in permanent vision loss. The key to saving vision lies in early diagnosis and timely treatment.

4. How often do I get my eyes checked if I have diabetes?

Those with diabetes should get a detailed eye examination done at least once a year, or more frequently if your eye doctor says so.

5. Is cataract surgery safe for diabetic patients? 

Yes. Diabetic patients can safely undergo cataract surgery with careful pre-surgical planning and blood sugar control. There may be a slightly higher risk of post-operative complications, so it is important to choose a trusted cataract eye surgeon.

Reference Sources:

1. https://www.cdc.gov/diabetes/diabetes-complications/diabetes-and-vision-loss.html#:~:text=Anyone%20with%20type%201%2C%20type%202%2C%20or%20gestational%20diabetes%20(diabetes%20while%20pregnant)%20can%20develop%20DR.%20The%20longer%20you%20have%20diabetes%2C%20the%20more%20likely%20you%20are%20to%20develop%20it.
2. https://www.cdc.gov/diabetes/diabetes-complications/diabetes-and-vision-loss.html#:~:text=This%20swelling%20is%20known%20as%20macular%20edema%20and%20is%20the%20most%20common%20cause%20of%20blindness%20in%20people%20with%20DR.%20About%20half%20of%20people%20with%20DR%20will%20develop%20macular%20edema.
3. https://www.cdc.gov/diabetes/diabetes-complications/diabetes-and-vision-loss.html#:~:text=People%20with%20diabetes%20are%20twice%20as%20likely%20to%20develop%20open%2Dangle%20glaucoma%2C%20the%20most%20common%20type.