PATIENT INFORMATION - Glaucoma Filtering

The Glaucoma Filtering Service is a community-based NHS service provided by specially trained optometrists working in local optical practices.

It is designed to assess patients who have been referred by their optometrist following a routine eye test.

During an eye test, several screening checks are carried out to assess eye health. These may include tests such as measuring eye pressure (e.g. the “air puff” test), examining the optic nerve, or checking your peripheral (side) vision.

Sometimes these screening tests suggest that further investigation is needed. This does not necessarily mean that you have glaucoma, but it is important to carry out more detailed tests or repeat measurements to be sure.

The purpose of the Glaucoma Filtering Service is to:

• Carry out more detailed assessment of your eyes
• Repeat or confirm any abnormal screening results
• Check whether you are at risk of glaucoma
• Decide whether a referral to hospital eye services is needed

This helps ensure that patients who are referred to hospital are appropriate and that unnecessary referrals are avoided. You will also be able to ask questions and discuss any concerns about your eye health.

This service is for patients who:

• Have been referred by their optometrist following an eye test
• Have had screening results that require further investigation
• May have raised eye pressure or other signs suggestive of glaucom

Glaucoma is a group of eye conditions that can damage the optic nerve, often linked to increased pressure inside the eye. It usually develops slowly and may not cause noticeable symptoms in the early stages, which is why assessment and monitoring are important. If left untreated, glaucoma can affect your vision.

During your appointment, the optometrist will carry out a detailed assessment including:

• Asking about your eye health and general medical history
• Measuring your vision
• Measuring the pressure inside your eyes (contact tonometry)
• Checking your peripheral (side) vision using a visual field test
• Examining your optic nerve (the nerve at the back of your eye)
• Assessing the drainage angle of your eye (anterior chamber angle)

These tests expand on the screening tests performed during your eye test and determine whether onward referral to the hospital eye service is needed.

During the assessment the optometrist may need to use eye drops to improve the view of the back of your eye.

After using dilating drops your vision may be temporarily blurred and you may be more sensitive to light. You should not drive until your vision returns to normal and it is recommended to bring sunglasses with you.

After your assessment, one of the following may happen:

• No further action needed – your results are within normal limits you’ll be advised to continue having routine eye tests.
• Referral to hospital eye service – if further specialist assessment or treatment is required

This service is NHS-funded, so there is no charge for the assessment.

Being referred to this service does not mean you have glaucoma. It simply means that your optometrist has referred you for a more detailed assessment.