Your eye doctor may use one of these optic nerve computer imaging techniques as part of your glaucoma examination.

By imaging your optic nerve over time during multiple visits to your eye doctor, these machines can help monitor and detect loss of optic nerve fibers.

The Heidelberg Retina Tomograph (HRT) is a special laser that produces a three-dimensional high-resolution image of the optic nerve. This test provides clinicians with measurements of nerve fiber damage (or loss).

The Nerve Fiber Analyzer (GDx) uses laser light to measure the thickness of the nerve fiber layer. When thinning, this layer gives important clues to physicians about the presence of glaucoma.

Optical Coherence Tomography (OCT), which measures the reflection of laser light much like an ultrasound measures the reflection of sound, can directly measure the thickness of the nerve fiber layer and create a three dimensional representation of the optic nerve.