Glaucoma Screening

Early diagnostic programme for glaucoma

Glaucoma is a disease that causes thinning of the nerve fibre layer in the retina and over time results in a gradual loss of vision which could lead to blindness if left untreated. Glaucoma is often called the “sneak thief of sight” because it is painless and symptoms appear slowly. In fact up to 50% of those with the disease remain unaware that they have it.

OCT and Glaucoma

Ocular Coherence Tomography (OCT) is an advanced eye scan similar to ultrasound but using light rather than sound waves. It is used for diagnosis of early glaucoma; for follow up of glaucoma patients under treatment and in relatives of glaucoma patients to establish a baseline from which to work as these people have a five times greater risk of glaucoma.

The OCT utilises a technology that assesses the structure of the optic nerve in great detail and can help in the detection of early signs of glaucoma before any vision loss has occurred. Each section of the nerve can be measured helping to make the diagnosis of glaucoma a lot easier.

How does the scan work?

When the OCT scans your eyes it is measuring the thickness of the nerve fibre layer in the back of the eye. The measurements of the nerve fibre layer are mapped by the software and compared to a database of normal values. The Optometrist interprets the examination findings in the clinical context of the patient as well as applying their observational skills of the optic nerve in their diagnosis.

Upon further visits the OCT scan also provides a comprehensive history that enables us to analyse the results and detect if there is any loss of nerve fibre thickness which may be an indication of glaucoma.

Who should be tested for Glaucoma?

Glaucoma can affect people of all ages and races however those at greatest risk are:

People over the age of 40
Anyone with high eye pressure
Anyone with a family history of glaucoma
People of African or Caribbean origin
Anyone who is very short-sighted
Long-term steroid users

What is the advantage of the OCT examination over the standard test for Glaucoma?

OCT Scan

The real strength of the OCT scan is that it can assist in detecting nerve fibre layer loss before any loss of vision has occurred. Early detection means we will have more time to manage the glaucoma and protect your vision.

Eye Pressure Test

An eye pressure test is normally used to detect glaucoma, however a number of those who develop glaucoma have normal eye pressures.

Visual Field Test

A visual field test shows the progression of the disease and is vital in monitoring glaucoma. Often 25-40% of the nerve fibre thinning has already taken place though before a visual field test can detect a problem.

Optic Nerve Assessment

Changes can be observed at the back of the eye to show glaucoma damage but these changes often occur after nerve fibre thinning has already taken place and visual field has been lost.