Clinicians will refer to someone as a ‘glaucoma suspect’ if they think the person might be showing early signs of glaucoma but they are not yet sure. Many people suspected of having glaucoma at this stage turn out not to have it at all, but some do develop it in time and it is these people who can benefit the most from timely treatment.
If someone has a very high intraocular pressure or very advanced optic nerve damage then the diagnosis of glaucoma is usually straightforward. However sometimes it is not entirely clear whether someone has glaucoma or not. The early signs of glaucoma can be subtle, and many glaucoma patients have a normal pressure.
Who is at risk?
Older individuals and individuals with a family history of glaucoma.
Glaucoma suspects have no symptoms to suggest eye disease. They are usually identified as glaucoma suspects during routine checks by their optometrist.
There is no single test that is 100% effective in confirming the diagnosis of glaucoma all the time. Sometimes the only way to be sure that someone has glaucoma is to arrange follow up examinations (every 4-6 months or so) to work out whether progressive damage is occurring to the optic nerve in one or both eyes. Features in the examination which might lead to a patient being classified as a glaucoma suspect include:
- A high pressure within the eyeball but with no optic nerve damage yet (this is also referred to as ocular hypertension)
- A ‘suspicious’ optic disc appearance on examination such as ‘cupping’ of the disc or thinning of the neuro-retinal rim or nerve fibre layers.
These are changes that can be seen with glaucoma, but can also be seen in other conditions such as myopia where it may be a variation of normal.
Other risk factors for glaucoma such as a strong family history but without definite changes to the optic nerve as yet. Generally speaking, glaucoma suspects will not show any visual field defects on testing, or may show some field defects which are not yet entirely convincing as evidence of glaucoma.
Usually a person thought to be a glaucoma suspect will not be treated for the condition until the diagnosis is confirmed. Typically, glaucoma advances slowly so its progress can be tracked safely without treatment until the diagnosis is confirmed.
It is very important that someone suspected of experiencing the early onset of glaucoma has regular checks to make sure there is no continuing damage to the optic nerve. Even though a person is not yet receiving any treatment for the condition, she or he may still risk losing their vision if in fact they do turn out to have glaucoma.