Glaucoma Detection: Screening and Diagnosis at Washington Eye Physicians & Surgeons
Early detection, through regular and complete eye exams, is the key to protecting your vision from damage caused by glaucoma. A complete eye exam includes various tests to accurately diagnose glaucoma. Please see the details on glaucoma screening below to get an idea of how thorough the diagnostic process is with Washington Eye Physicians & Surgeons. It is important to have your eyes examined regularly even if you do not possess early symptoms of glaucoma.
Get regular eye exams:
- before age 40, every two to four years
- from age 40 to age 54, every one to three years
- from age 55 to 64, every one to two years
- after age 65, every six to 12 months
To get a better understanding of the equipment used in our glaucoma screening and diagnosis process, please read about the following diagnostic tests.
Visual Field Test
Glaucoma is referred to as the sneak thief of sight and can be present without a patient even knowing. As the nerve fibers in the optic nerve are damaged in glaucoma, there is a gradual and painless loss of vision. The loss often goes unnoticed. However, if untreated, glaucoma may eventually affect central vision, as well. Usually it is only with this more advanced stage of glaucoma that one can recognize loss of vision without special tests. The term visual field refers to the area of a scene you can see with your eyes fixed on one location. For example, while watching a stop light, you may notice a car pulling up beside you in the next lane. Your peripheral vision enables you to see the movement of the car. The visual field is quite extensive when both eyes are working properly but with glaucoma, the field of view is reduced.
A visual field test measures two things:
- How far up, down, left and right the eye sees without moving.
- How sensitive the vision is in different parts of the visual field.
OTC (Optical Coherence Tomographer)
This new machine manufactured in Germany by Zeiss is called an HD-OCT. It has the ability to capture images of eye tissue at a near individual cell level of resolution. In addition, it can show each layer of tissue in the eye allowing our glaucoma eye specialists to pinpoint the exact location of tissue damage. This sophisticated piece of equipment aids in the diagnosis and management of many ocular conditions, including glaucoma and macular degeneration. OCT is a safe, painless and quick procedure that does not require dilation of the pupils. A laser scans the retina, optic nerve, cornea, or anterior chamber in just a manner of seconds to provide our glaucoma doctors with detailed information regarding the microscopic details of the eye. Anyone who has glaucoma or is a glaucoma suspect would benefit from undergoing this diagnostic test.
Heidelberg Retina Tomograph (HRT)
The HRT is a modern diagnostic device used in the diagnosis and management of glaucoma. Specialized lasers in the HRT scan form a 3-dimensional topographic map of the optic nerve and adjacent retina. Analysis of these images can show measurements different enough from normal to help in diagnosing glaucoma. The HRT test can detect symptoms years before glaucoma symptoms have become apparent to the patient. Since subtle changes in the optic nerve tissue can be the first sign of glaucoma and can precede visual field changes, the HRT test may enable eye doctors to diagnose the disease earlier. A major advantage of the HRT test is that by taking a series of measurements over time, it can detect small changes that may otherwise go undetected by traditional methods of examination and glaucoma screening.
Pachymetry is the measurement of the thickness of the cornea, (the clear window on the front of the eye).
When the cornea is thinner than average, patients appear to have an increased risk of developing glaucoma. Pachymetry should be performed at least once in a glaucoma patient’s adult life if the eye pressure seems to be too low to explain glaucomatous optic nerve damage or if the eye pressure is higher than one would expect in the absence of any optic nerve damage.