How is glaucoma diagnosed?

Why should I test for glaucoma when my eyesight is fine?

Regular eye tests with your Optician are not just about whether you need glasses for vision. During an eye test, an optician or ophthalmologist also investigates the health of your eyes.

At the Hampshire Eye Clinic, conditions such as glaucoma, macular degeneration and even diabetes and high cholesterol can be detected during eye tests. It is therefore important to get your eyes tested regularly.

It is particularly important to get your eyes tested if you have a first degree relative (parent, child or sibling) with glaucoma, if you are African-Caribbean, Asian, diabetic, have low blood pressure or are short sighted. These factors may increase your risk of developing glaucoma.

Am I entitled to free eye tests?

You may be entitled to a free NHS eye test with your local optician if you belong to the list below, it is best to check with your local optician.

• You are aged 60 or over
• You have a diagnosis of diabetes or glaucoma
• You are aged 16 or under, or under 19 in full time education
• You’re 40 or over and have a close relative with glaucoma (your mother, father, sibling or child)
• You are registered as blind or partially sighted
• You or your partner receive certain benefits or you are under 20 and the dependent of someone receiving:
• Income Support
• Employment and Support Allowance
• Jobseeker’s Allowance
• Pension Credit Guarantee Credit
• Universal Credit

If you are not eligible, we can perform a full Glaucoma assessment in our friendly comfortable purpose built clinic.

In a recent survey performed by Glaucoma UK, over 65% of those surveyed said they had glaucoma diagnosed via a free eye test at their local optician.

Glaucoma is usually symptomless until late in the disease and having your eyes checked is the only way to find out whether you have it and start the necessary treatment.

What happens at an eye test?

How do we at Hampshire Eye Clinic test for Glaucoma?

You can book an eye consultation directly with us or be referred by your optician or GP after having an optician’s test. A referral does not mean that you definitely have glaucoma or that you are at risk of losing sight. It just means that your optician has found some signs suggestive of a diagnosis of glaucoma and needs further investigation to ensure you are not at an increased risk.

Your optician will not diagnose you with glaucoma.

We will perform the following tests to provide a detailed assessment of your eyes and its health.

Visual field test

A visual field test checks whether your peripheral vision is complete. The peripheral vision is the vision away from the centre which is usually the first to become affected in Glaucoma. This can go unnoticed for a long time until it progresses into the centre. You will be asked to sit at a machine and look at a small light directly in front of you. You will be are asked to press a button whenever you see a dot of light. Patients with glaucoma may have some gaps in their field of vision and so miss some of the flashing lights. It is important that anyone with Glaucoma has this test regularly to ensure their condition is stable and not worsening.

Eye pressure test

Eye pressure is the biggest risk factor for Glaucoma but is poorly understood and needs to be evaluated against other factors. An optician will usually perform an “air puff” test of contact tonometry test. A small puff of air is directed at your eye and bounces back onto the machine, which measures the pressure within the eye (intraocular pressure or IOP). If you have glaucoma or ocular hypertension, your IOP may be raised, you can however develop Glaucoma at normal IOP. A more accurate glaucoma IOP test is performed with contact tonometry which some opticans may use or can be done here in our clinic.

Optic nerve assessment

Glaucoma is an optic neuropathy which means the optic nerve becomes damaged. The optic nerve transmit images to the brain captured by the eye in a similar way a cable is used to download images from a camera to the computer. At the Hampshire Eye Clinic, the consultant will examine the back of your eye and in particular, your optic nerve to check for changes consistent with optic nerve damage. This examination will be supported by the use of optic nerve photos optical coherence tomography (OCT) to monitor changes.

OCT can detect structural changes in the eye before the onset of visual change. An OCT allows visualisation of your eyes in greater detail, by seeing beneath the surface of the eye. A photograph will show us the top face of the optic nerve in 2 dimensions, an OCT will cut the nerve in half and turns it on its side so we can see all the layers inside in 3 dimensions.

We are then able to measure the thickness of these layers to get a clearer idea of your eye health. This technology is also commonly used by us to detect retinal and macula conditions such as age related macular degeneration (AMD) and diabetes.

The above tests compliment a full eye health check which will include pupil assessment, colour vision and corneal thickness (pachymetry) to give us a complete picture of your eyes and any potential issues with your vision.