How Diabetes Can Affect Your Eyes: Dry Eye, Retinopathy & More

Diabetes affects many people all over the world, with an estimated 5.6 million people living with diabetes in the UK alone1. Diabetes can also contribute to a number of other potential health conditions2, including diabetes-related eye conditions. In this blog, we’ll explore what diabetes is and how it can impact both the front and back of your eyes.

What is diabetes?

Diabetes is a condition in which the body is unable to regulate blood sugar levels within a safe range. It usually occurs because insulin a hormone, which is produced in the pancreas, becomes less effective in our body, or is not produced in sufficient amounts by the pancreas. So, when somebody has diabetes, their blood sugar levels can become too high or too low. 

There are two main many types of diabetes, but the most common one is type 2 diabetes.

Type 1 diabetes

In type 1 diabetes, the pancreas either doesn’t make insulin or produces too little. It can affect people at any age but mostly develops in children and young adults. People living with type 1 diabetes will need daily insulin injections to keep their blood glucose levels under control. Common symptoms may include sudden weight loss, lack of energy, constant hunger, needing to urinate more frequently, blurred vision and increased thirst.

Type 2 diabetes

Type 2 diabetes, on the other hand, occurs in adults later in life and is typically indicated by insulin resistance, meaning that the body doesn’t respond to insulin. Because of this, blood glucose levels rise, releasing more insulin to keep up. For some people with type 2 diabetes, this can eventually exhaust the pancreas, resulting in a reduction in insulin production over time. This can cause even higher blood glucose levels, known as hyperglycaemia. Many people with type 2 diabetes can delay or prevent the condition from worsening with treatment and appropriate lifestyle changes.

Diabetic retinopathy 

Diabetic retinopathy is a complication of the back of the eyes which can be caused by diabetes. Consistently high  blood glucose levels, can damage  blood vessels, including some important vessels in the eyes that help supply blood to the retina , the part of the eye that captures what we see. Tiny bulges may develop in the blood vessels, which can leak blood. If the condition worsens, there is a risk of wider-spread changes to the retina, which could impact vision long-term3. The condition can develop in anyone who has type 1 or type 2 diabetes. 

Common symptoms of diabetic retinopathy can include gradually worsening vision and eye floaters.

Diabetic Macular Oedema (DMO)

DMO is a complication of diabetes which can also impact  vision. This occurs when leaky blood vessels cause a fluid build-up in the middle of the retina, in a region called the macula. Since the macula is an important part of the retina that allows us to see things in detail, including colour vision, having diabetic macular oedema can cause significant changes to your vision. 

Reducing your chance of developing diabetic retinopathy

Left untreated, diabetic retinopathy can lead to serious complications. There are a number of  things you can do to manage your blood sugars and keep your blood pressure in the target range, which can protect your blood vessels and prevent this diabetes-related eye condition. These include: 

  • Get your eyes screened regularly
  • Managing your diabetes and keeping blood sugar at target levels
  • Make healthy lifestyle choices such as healthy eating and not smoking
  • Exercise regularly
  • Keep blood pressure and cholesterol under control
  • Keep your eye care professional updated about any changes to your eyes or vision

Other eye conditions related to diabetes

Alongside dry eyes and diabetic retinopathy, diabetes can also increase your risk of developing the following eye conditions.

Glaucoma

Those who have diabetes may be more likely to develop glaucoma. Glaucoma is  a condition where pressure inside the eye increases more than usual if the blood flow to the optic nerve is affected by diabetes. If diabetic retinopathy progresses to an advanced stage and new blood vessels start to grow on the iris, the coloured part of your eye, then this can lead to a secondary type of glaucoma4

Cataracts 

Diabetes can also cause cataracts, which is a condition that causes cloudiness of the lens in your eye. This is because high blood sugar levels can cause the lens in your eyes to swell over time, eventually changing its structure and resulting in opacities  known as cataracts.

Diabetes & Dry Eye

Diabetes has linked to an increased risk of developing Dry Eye Disease. This is due to the effects of diabetes on the body's ability to produce sufficient tears, or tears evaporating too quickly from the surface of the eye, which can lead to discomfort, irritation, blurred vision, and potential longer term damage to the eyes5. It's important for individuals with diabetes to be aware of this potential complication and to consult with an eye care 2professional for appropriate management and treatment options and to make sure your eyes are comfortable 

You can find out more about Dry Eye in diabetes here.

Tear film & tear glands explained

The film of tears over the eye has several important functions, including:

  • Helping us see clearly
  • Keeping our eyes comfortable
  • Providing nourishment for the surface of the eye
  • Protecting the surface of the eye
  • Washing away dust and debris

Tears are produced by tiny glands above your eyes and in your eyelids, and contain three different components:

  • An outer, oily (lipid) layer
  • A middle, watery layer
  • An inner mucin layer, which is closest to the surface of the eye

Each layer serves a different purpose. The lipid layer prevents tears from evaporating too quickly. Hydration, nourishment and antibodies are provided by the watery layer to fight off any infection. Mucin helps the tear film stick to the surface of the eye and not run down your cheeks. 

Any imbalance in the quantity or quality of these tear layers will make your eyes uncomfortable and they may need some extra help to restore comfort, health and good-quality vision. 

What’s the link between diabetes & Dry Eye? 

Key factors that contribute to dry eye in individuals with diabetes:

  • Nerves on the surface of the eye: Diabetes can affect the nerves throughout the body, including those that control tear production. If the nerve signals that stimulate tear production from the tear glands are interrupted, tear production can decrease. Sometimes, because the sensory nerves in the eye have also been affected, symptoms of Dry Eye might not be as noticeable. This causes risks of delayed treatment.
  • Inflammation: As the body becomes less sensitive to insulin, insulin resistance develops, and this is related to higher levels of inflammation in the body. Long-term inflammation in the eyes can damage the glands that produce tears6. If not enough tears are produced, or if those tears don’t contain enough of the right components as above, dry eye can be the result.
  • Meibomian gland dysfunction (MGD): High blood sugar can cause the oil-producing glands in the eyelids to become clogged, leading to dry eyes. The nerves that control these glands can also become damaged, meaning it’s more difficult for the body to regulate the production of these oils / lipids.

Symptoms of dry eye

Dry Eye Disease in people with diabetes can cause a range of symptoms, including:

  • Persistent dryness and a gritty sensation in the eyes
  • Redness and irritation
  • Watery eyes: excessive tearing due to the eye's reflex response to dryness
  • Blurred or fluctuating vision
  • Light sensitivity 

Preventing or treating Dry Eye in diabetes 

It is always best to work with your healthcare team to manage diabetes properly. This also includes your eye care professional to ensure your eye health is managed too. 

Below are some ways you can treat and reduce the risk of diabetes-related dry eye: 

  • Blood sugar control: Maintaining good blood sugar control is important and can help reduce nerve damage and inflammation. This means eating a healthy, balanced diet and exercising regularly. If you have been prescribed medication for your diabetes, then take them regularly as directed.
  • Regular eye examinations: Attending regular check-ups with your eye care professional can provide opportunities to check on any complications such as retinopathy and assess the surface of your eye for signs of dry eye. An eye care professional can offer expert advice at your examination to help manage symptoms and prevent them from worsening.
  • Lifestyle adjustments: Making certain lifestyle changes can also help. Avoid smoking, limit screen time use, and use humidifiers to add moisture to indoor air. Eating a diet rich in omega-3 fatty acids and staying well hydrated can also be useful7.
  • Heat treatment: Use of a reusable warming eye mask such as the Blepha EyeBag® daily will not only provide relief from the symptoms of dry eye but will help the glands which produce the oily layer of the tear film. This can improve the quality of your tears and reduce them from evaporating too quickly.
  • Eyelid hygiene: Thoroughly cleaning the eyelids daily with Blephaclean® eyelid wipes will reduce symptoms associated with irritated and blocked eyelids, which affects tear quality.
  • Lubricating eye drops: Using preservative-free lubricating eye drops such as Thealoz® Duo provides instant and long-lasting relief from dry eye symptoms8.
  • Watery (Lipid-deficient) dry eye: If the oily lipid layer in your eyes is causing tears to evaporate too quickly, TheaLipid® can help restore the natural tear film, alleviating any watering, streaming or burning sensations in the eyes.
  • Night-time relief: Using Thealoz® Duo Gel before going to sleep can provide relief from diabetes-related dry eye symptoms and allow you to sleep comfortably.

Start giving your eyes some TLC (Théa Loving Care). You can use our online symptom checker to help you identify the symptoms you may be experiencing. We always recommend you talk to an eye care professional who will be able to diagnose your symptoms and offer advice to support you.

Understanding how diabetes can affect your eyes and how you can stay on top of your symptoms is important for keeping your eyes healthy and comfortable, while also protecting your vision for many years to come. 

Maintaining a good eye routine is key to healthy eyes. If you have any concerns about diabetes or eye health, we recommend speaking to a specialist, whether it’s your doctor or an eye care professional.

  

1 https://www.diabetes.org.uk/about-us/about-the-charity/our-strategy/statistics

2 https://www.diabetes.org.uk/guide-to-diabetes/complications

3 https://www.nhs.uk/conditions/diabetic-retinopathy/stages/

4 Chauhan MZ, Elhusseiny AM, Kishor KS, Sanvicente CT, Ali AA, Sallam AB, Bhattacharya SK, Uwaydat SH. Association of Primary Open-Angle Glaucoma with Diabetic Retinopathy among Patients with Type 1 and Type 2 Diabetes: A Large Global Database Study. Ophthalmology. 2024 Jul;131(7):827-835

5Zhang X, Zhao L, Deng S, Sun X, Wang N. Dry Eye Syndrome in Patients with Diabetes Mellitus: Prevalence, Etiology, and Clinical Characteristics. J Ophthalmol. 2016;2016:8201053.

De Freitas GR, Ferraz GAM, Gehlen M, Skare TL. Dry eyes in patients with diabetes mellitus. Prim Care Diabetes. 2021 Feb;15(1):184-186.

Fang W, Lin ZX, Yang HQ, Zhao L, Liu DC, Pan ZQ. Changes in corneal nerve morphology and function in patients with dry eyes having type 2 diabetes. World J Clin Cases. 2022 Apr 6;10(10):3014-3026.

6 https://www.webmd.com/diabetes/inflammation-and-diabetes

7 Wang WX, Ko ML. Efficacy of Omega-3 Intake in Managing Dry Eye Disease: A Systematic Review and Meta-Analysis of Randomized Controlled Trials. J Clin Med. 2023 Nov 10;12(22):7026.

8 Ballesteros-Sánchez A, Martinez-Perez C, Alvarez-Peregrina C, Sánchez-Tena MÁ, De-Hita-Cantalejo C, Sánchez-González MC, Sánchez-González JM. Trehalose and Dry Eye Disease: A Comprehensive Systematic Review of Randomized Controlled Trials. J Clin Med. 2023 Nov 25;12(23):7301.

Gawash A, Simonetti A, Lo DF, Shamilov DD, Kumar A, Wong JC. Assessing the therapeutic role of trehalose and hyaluronic acid: implications for patient care. Int Ophthalmol. 2024 Oct 1;44(1):398.