Community Eyecare

Glaucoma and Ocular Hypertension


Glaucoma is a term that describes a group of eye conditions that affect vision. Glaucoma often affects both eyes, usually in varying degrees. One eye may develop glaucoma quicker than the other. Usually, glaucoma results in damage to the optic nerve followed by a visual loss if untreated.

Glaucoma affects 2% of the population in the UK but, 50% of those suffering glaucoma may remain undetected due to the silent nature of the condition.

Estimated people in the UK suffer from glaucoma
Number of stable patients managed by CHEC

Glaucoma occurs when the drainage tubes (trabecular meshwork) within the eye become slightly blocked. This prevents eye fluid (aqueous humour) from draining properly.

When the fluid cannot drain properly, pressure builds up. This is called intraocular pressure. This can damage the optic nerve (which connects the eye to the brain) and the nerve fibres from the retina (the light-sensitive nerve tissue that lines the back of the eye).

Attending regular optician appointments will help to ensure any signs of glaucoma can be detected early and allow treatment to begin.

Glaucoma is the name given to a group of eye conditions that cause optic nerve damage and can affect your vision. Glaucoma damages the optic nerve at the point where it leaves your eye.

Ocular hypertension (OHT) is different to glaucoma. It is essence means high eye pressure and has no real significance. With OHT there is no damage to the optic nerve therefore there is no vision loss.

In 2009, The National Institute of Health and Clinical Excellence (NICE) released guidelines on the management of ocular hypertension and Glaucoma. These were updated in 2017 under guidelines NG 81.

The benchmark now used to monitor or decide on treatment for OHT or suspected Glaucoma is outlined in the table below. Do not be surprised that after many years of treatment or monitoring, that a doctor will ask you to stop treatment and potentially reassess based on the table below.

The table below shows treatment parameters used for OHT and suspect glaucoma:

CCT More than 590 micrometres 555-590 micrometres Less than 555 micrometres Any
Untreated IOP (mmHG) > 21 TO 25 > 25 TO 32 > 21 TO 25 > 25 TO 32 > 21 TO 25 > 25 TO 32 > 32
Age (years) Any Any Any Treat until 60 Treat until 65 Treat until 80 Any
Treatment No treatment No treatment No treatment BB PGA PGA PGA


What is glaucoma?

Glaucoma is a group of eye conditions where the eye pressure is too high for your eyes and can cause nerve damage and over a longer-term period visual loss which is irreversible. Don’t worry, glaucoma is generally picked up early by your optometrists and treated by a doctor, so significant visual loss is unusual.

How do we investigate glaucoma?

There are several tests that help us diagnose glaucoma. Even then, the results may not be able to 100% diagnose glaucoma. The core tests are:
  • A visual acuity test.
  • A measure of the thickness of your cornea, called a pachymetry.

After the tests, what happens?

Generally, the eye tests are undertaken by an optician or technician/nurse and these are then available for the doctor to review. You will be informed of the outcome of the tests within the next week or will be seen by the doctor at appointments.

Can I drive to my appointments?

As for any eye appointments, we would recommend that you do not drive. It may be that the doctor decides not to put in dilating drops but we often can’t decide that until the day of the consultation.

How long will I have glaucoma?

Glaucoma is a lifelong condition and, as such, you will be treated and monitored for life. This is often not too intrusive other than eye drops daily and then appointments every 6 to 12 months.

Glaucoma NICE Guidelines 2017

Glaucoma Information Leaflet

IGA Ocular Hypertension Information leaflet

IGA Primary Angle Closure Glaucoma Leaflet