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Quadrant Analysis is defined as a diagnostic method used in automated perimetry (visual field testing) that divides the patient's field of view into four equal sections: superior-temporal: superior-nasal: inferior-temporal: and inferior-nasal. This allows for:
Glaucoma often damages the optic nerve in a "top-down" or "bottom-up" fashion. Quadrant analysis allows the doctor to see if the vision loss is respected by the "horizontal raphe" (the midline of the eye). If one quadrant is significantly worse than its neighbor; it is a strong clinical indicator of glaucomatous nerve fiber layer damage.
This is a specific type of vision loss where a person is blind in exactly one quarter of their visual field in both eyes. This is rarely an "eye" problem and is usually a "brain" problem; such as:
In a healthy eye: the top and bottom halves of your vision should be roughly equal in sensitivity. Quadrant analysis calculates a "Glaucoma Hemifield Test" (GHT); which mathematically compares the superior quadrants to the inferior ones. A significant "asymmetry" between them is often the very first sign of glaucoma; appearing years before the patient notices anything wrong.
Yes: both automated (Humphrey) and manual (Goldmann) visual fields utilize quadrant-based mapping. By checking each quadrant independently: the doctor can determine if a patient is safe to drive; as many states require a certain amount of "uninterrupted" vision in specific quadrants to maintain a legal license.
If the quadrant analysis shows a "cluster" of missed points in one area; it means you have a localized loss of sensitivity. This is exactly what the test is designed to find. It doesn't mean you are doing the test "wrong;" it means the computer has successfully mapped a physical blind spot in your vision.
Yes: the printout from your visual field test usually shows a "Total Deviation" and "Pattern Deviation" map. You will see four clear areas divided by a cross-hair. Areas with dark squares represent the quadrants where your vision is below the expected average for your age group.
The computer software accounts for your age. It compares your quadrant sensitivity to a database of thousands of "normal" people in your same age bracket. This ensures that the quadrant analysis is detecting "disease" rather than just the natural: slight decline in vision that comes with getting older.