Glaucoma
Which tests are used to diagnose glaucoma?
No single test diagnoses glaucoma. The diagnosis combines eye pressure measurement, examination of the optic disc, gonioscopy of the drainage angle, a visual field test and OCT imaging of the optic nerve and nerve fibre layer. Corneal thickness is sometimes measured too. Results are compared over time to detect change.
The core tests and what each one shows
- Tonometry measures the pressure inside the eye, the main treatable risk factor
- Optic disc examination looks for cupping, thinning and small disc bleeds
- Gonioscopy shows whether the drainage angle is open, narrow or closed, which decides the type of glaucoma and the treatment
- Visual field testing maps the sensitivity of your vision point by point and shows functional loss
- OCT measures the thickness of the nerve fibre layer in microns and can detect thinning before fields change
- Corneal thickness measurement helps interpret pressure readings
Why repeat testing matters
Glaucoma is defined by change over time. Two visual fields or scans separated by months tell your ophthalmologist far more than any single result, because they show whether damage is stable or progressing and therefore whether treatment is doing enough.
What to expect practically
All of these tests are painless. Tonometry uses a numbing drop, the field test asks you to press a button when you see faint lights, and OCT simply photographs the back of the eye with light. Pupil dilating drops are often used, and they blur near vision for a few hours.
Frequently asked questions
- Do I need all the tests every visit?
- No. Pressure and examination happen each visit, while fields and OCT are repeated at intervals your ophthalmologist chooses, more often when the picture is changing.
- Are these tests available in Abuja?
- Yes. Applanation tonometry, visual field analysis, OCT and digital fundus imaging are performed at our hospital in Garki.
Concerned about these symptoms?
Arrange an eye examination with our consultant ophthalmologist in Garki, Abuja.
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Related answers
- What is a visual field test like?
- What does an OCT scan show in glaucoma?
- What is gonioscopy and why is it done?
- What is eye pressure, and what is a normal reading?
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