Diabetes and Your Eyes: Can high blood sugar cause Diabetic Retinopathy?

You may have heard that diabetes is a disease that requires constant vigilance and management. This is because diabetes causes a multitude of physiological changes in the body, leading to a range of other diseases that can sometimes prove to be fatal. One such disease is diabetic retinopathy – a condition that can cause vision loss if left untreated. 

To understand the link between diabetes and your eyes, you must understand how the eye functions. The coloured part of the eye is known as the iris, and the dark spot in its centre is known as the pupil. Light enters your eyes through the pupil and falls on a light-sensitive tissue at the back of the eye known as retina. Nerves within the retina transform light into electric signals, which are then sent to your brain and interpreted as what you see. Patients suffering from Type 1 and Type 2 diabetes with a history of unmanaged sugar tend to develop damages in the blood vessels of the retina. Naturally, this affects the retina’s ability to relay information to your brain, leading to vision loss. 

How does diabetes affect the eyes?

While diabetic retinopathy is the most common disease caused by diabetes, it does have other effects on your eyesight. Some of the other eye conditions caused by diabetes are:

• Macular edema: This is when fluid accumulates within retinal layers at the centre, leading to blurriness and vision loss.
• Retinal detachment: This is when the retina detaches entirely from the underneath supportive tissue in the eye, causing blindness.
• Neovascular glaucoma: This is a form of glaucoma in which new blood vessels grow within the eye, causing problems with the eye’s natural fluid drainage system and leading to rising intraocular pressure.
• Vitreous hemorrhage: This is when new blood vessels formed in the eye burst, leading to blindness. 

Types of diabetic retinopathy

There are two main types of diabetic retinopathy – non-proliferative diabetic retinopathy (during which damaged blood vessels leak fluid into the eyes) and proliferative diabetic retinopathy (during which the retina starts growing new blood vessels). The two types of diabetic retinopathy are further broken down into 4 stages based on the damage to the blood vessels on the whole.  

1. Mild nonproliferative diabetic retinopathy: In this stage, diabetes causes the blood vessels in the retina to swell. The swelling can also cause blood to leak onto the macula (centre of the retina), leading to problems with central vision.
2. Moderate nonproliferative diabetic retinopathy: During this stage, the swelling of the blood vessels starts interfering with the blood flow to the retina.
3. Severe nonproliferative diabetic retinopathy: The number of blocked blood vessels increases, leading to a significant blockage in blood flow. The body begins to compensate by growing new blood vessels in the retina.
4. Proliferative diabetic retinopathy: New blood vessels begin forming on the retina. As these new vessels are quite fragile, the chances of leaking fluid onto the macula increases. This is an advanced stage of the condition and can even cause blindness. 

Can eyesight issues caused by diabetes be treated?

Treatment depends on the type of diabetic retinopathy you may have. If the condition is within the non-proliferative stages (as detailed above), your doctor may suggest any of the following:

• Photocoagulation laser surgery: this reduces swelling in the retina
• Steroid injections: these reduce swelling within the eye and reduce blurriness
• Anti-VEGF drugs: these can help in halting or delaying the macular degeneration caused by swelling or leaking blood vessels
• Vitrectomy: this is a surgery that removes scar tissues and excess fluid and/or leaked blood within the eye so that the light falls on the retina properly
• Retinal reattachment surgery: if diabetes has caused retinal detachment, your doctor will recommend surgery to reattach it and restore vision. The surgery must be carried out within a few days of the diagnosis to be successful.
• Surgery to create new drainage systems in the eyes:  if you have developed Neovascular glaucoma due to diabetes, you may have to undergo surgery that helps with draining fluids from the eyes. Sometimes, if the condition is not too severe, it can be treated with medications that reduce the pressure in the eyes. 

Why CFS?

At Centre for Sight, we have over 50 eye care centres throughout India and a network of over 150 renowned doctors working with us. Our high-tech diagnostic lab can deliver results quickly and accurately so that we can offer you timely intervention and effective treatment. If you are suffering from any vision problems, or have recently been diagnosed with diabetes, make sure you schedule an appointment with us to help you preserve your eyesight or treat any conditions that may be hindering the same. 

Article: Diabetes and Your Eyes: Can high blood sugar cause Diabetic Retinopathy?

Author: CFS Editorial Team   |   Nov 05 2021 | UPDATED 07:00 IST

*The views expressed here are solely those of the author in his privatecapacity and do not in any way represent the views of Centre for Sight.