How is Glaucoma Detected?
Glaucoma is typically detected upon routine eye examination since sufferers do not have symptoms at earlier stages of the disease. During a routine comprehensive eye examination, the eye pressures are taken and the optic nerve is inspected with lens magnification. If eye pressures are high and optic nerves appear to have damage, there is a good chance the patient has glaucoma. Three additional tests are typically done to increase the likelihood of the diagnosis: Pachymetry, HRT/OCT/Disc photos, and visual field examination.
- Pachymetry is a measurement of the thickness of the eye. It helps in interpreting the eye pressure reading. The thinner the cornea is, the more likely the falsely low pressure reading, and vice versa.
- HRT (Heidelberg Retina Tomograph) and OCT (Ocular Coherence Tomography) are computer imaging technologies that scan and take pictures of the retinal and optic nerve tissues. They help the doctor to detect glaucoma nerve damage as well as progression of the disease over time. Only one of these tests is necessary. Each practice or doctor has their preference for which test to do. Lee Eye Center has both machines. This test is done yearly and only takes a couple of minutes. Stereo photos of the optic nerve can be helpful to follow disease progression, especially, when HRT and OCT are not available.
- Visual field examination is a more subjective test of the peripheral vision, which is the first to become damaged from glaucoma. This test is done yearly and takes about 5-7 minutes to complete.
After combining the test results with visual inspection of the nerve, the eye doctor can give a more accurate determination of the presence of glaucoma and its severity.