GLP-1s and eye health: what you need to know

Diabetes can have a wide range of impacts on your health, including on your eye health.

People with diabetes are already at increased risk of developing eye conditions such as:

• Diabetic retinopathy

• Diabetic macular oedema

• Cataracts

• Glaucoma

In the UK, every adult patient with diabetes is invited for diabetic eye screening to monitor for changes to the back of the eye / retina as later stages of diabetic retinopathy or diabetic macular oedema may impair vision.

Meta analysis of real-world data and clinical trials have shown mixed data on the association of GLP-1 RAs and diabetic retinopathy. Some studies have shown progression of earlier stages of diabetic retinopathy with GLP-1 RA use whilst some have not shown any association.

Therefore, the current recommendation stands that any patient with diabetes, including those who are taking GLP-1s, should have a baseline diabetic eye screening and to continue to attend their regular monitoring appointments to ensure their eye health is maintained.

Non-Arteritic Anterior Ischemic Optic Neuropathy (NAION) is characterised by sudden and painless loss of vision in the affected eye. This occurs due to a reduced blood flow to the optic nerve.

In February 2026, the UK Medicines and Healthcare products Regulatory Agency (MHRA) issued guidance for clinicians regarding the very rare risk of NAION for those taking semaglutide medicines, which include some of the most common GLP-1s. The MHRA advises that patients with sudden loss of vision or rapidly worsening vision should be treated as an emergency and patients should attend their local eye casualty (where available) or A&E.

The risk is considered very low, with studies suggesting that NAION may affect up to 1 in 10,000 people taking semaglutide.

It is important that each patient is assessed individually. For many patients with obesity and Type 2 diabetes, the benefits of treatment will outweigh this small potential risk. Patients considering or taking GLP-1 medicines for weight loss should discuss the benefits and risks with their healthcare professional prescribing the medication.

Although NAION is very rare, sudden loss of vision should always be treated as an emergency and assessed urgently by an eye specialist.

Age-related macular degeneration (AMD) is a condition affecting the macula, the central part of the retina responsible for detailed vision. It can cause blurry vision and vision loss in the centre part of the vision. There are two types of AMD:

• Dry AMD (or early stage AMD) is a progressive condition with no cure. Treatment focuses on supporting patients to minimise impact on everyday life.

• Wet AMD where abnormal blood vessels grow underneath the retina. These leak fluid and damage the cells of the retina. Wet AMD can often be controlled with injections.

The evidence base is still evolving and no firm conclusions have been drawn into medical guidance. However, some observational studies have suggested a link between GLP-1s and an increased risk of wet AMD.

Idiopathic Intracranial Hypertension (IIH) is a build-up of pressure around the brain where the cause is unknown. The symptoms of IIH are varied but can include severe and constant throbbing headache and temporary losses of vision.

The evidence base here is small but from the studies which have been conducted, it appears that there is a positive effect of taking GLP-1s for IIH. Patients taking GLP-1s reported fewer headaches and a decrease in intra-cranial pressure. Further evaluation is required to substantiate any current studies.

Glaucoma is a group of conditions which damage the optic nerve and lead to irreversible sight loss if untreated.

Numerous studies have assessed the relationship between GLP-1 medications and glaucoma, and most have shown that GLP-1 medications offer a small protective effect against glaucoma. This has not yet impacted clinical practice or guidance and research is ongoing.