Q: I recently had a test of my peripheral vision at the opticians, who found a problem. I was referred to the hospital and had several other tests. We are now a year on and at the most recent appointment I was told there is no problem at all and I was discharged. Is this correct?
A: The commonest form of glaucoma is chronic simple open-angle glaucoma and in its earliest stages it can be symptomless.
The majority of cases involve a slow rise of pressure within the eyeball which slowly and quietly robs the patient of their vision, although low pressure types also exist.
Picking it up at a stage where it has not caused any loss of vision is crucial as there are successful treatments available.
The optician is crucial in this respect and they have several screening techniques. One is testing the pressure of fluid within the eyeball (usually with a ‘puff of air’ on to the eyeball) and the second is a test of peripheral vision, identifying flashes of light on a screen.
Both of these tests have their inaccuracies and only if abnormalities in pressure and peripheral vision are reproducible over time can the diagnosis be entertained.
It is therefore common to be referred with suspect glaucoma and to be subsequently discharged because the findings do not persist.
The hospital has additional tests that can be performed such as a more accurate pressure test and a mapping of the optic disc on the back of the eye (OCT, optical coherence tomography).
These tests and the monitoring of changes over time mean that detecting glaucoma has become an accurate science, if a slow one, so you can rely on the process and conclusion being correct.
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