Diopsys NOVA Vision Testing System This instrument provides our office with painless, non-invasive vision tests that utilize electrophysiological technology, including Visual Evoked Potential (VEP) and pattern Electroretinography (ERG).
Visual Evoked Potential (VEP) VEP measures the electrical activity in the vision system. When light from an image enters your eye, it is converted into electrical energy at the retina and travels through the optic nerve to the visual cortex of the brain which processes vision. The Diopsys NOVA-VEP test measures the strength of the signal reaching your visual cortex and how fast it gets there.
Pattern Electroretinography (ERG) ERG measures the function of your retina- the light-sensitive layer at the back of your eye. When light from an image enters the eye, it is converted into electrical energy by specialized cells in the retina. These cells send electrical impulses through the optic nerve to the brain where the image is processed. The Diopsys NOVA-ERG test records how well the cells of the retina are conveying electrical impulses within the eye.
Zeiss Humphrey Visual Field Analyzer This instrument is a key component in measuring a patient's subjective visual field changes. In other words, this instrument allows our doctors to understand how glaucoma or other disease processes affect what a patient is actually able to see. This instrument can help to distinguish glaucomatous damage from visual field changes due to other processes.
Heidelberg Optical Coherence Tomographer This instrument is a sensitive indicator of retinal nerve fiber layer loss. In other words, this instrument helps our doctors know changes are taking place in the back of a patient's eye prior to the patient noting actual vision changes. This instrument is capable of detecting nerve fiber layer loss long before it becomes apparent to a patient, and is very useful in tracking the effectiveness of a treatment regimen.
DGH Pachymeter This instrument is used to measure the thickness of a patient's cornea, which is the clear dome on the front of the eye. Corneal thickness is important in the diagnosis and treatment of glaucoma as it directly affects the intraocular pressure measurement done on office visits. Thin corneas are a risk factor for developing glaucoma, and must be taken into account by doctors when deciding what a "safe" intraocular pressure is for any given patient.
Dr. Holmes using the OCT on a patient.