Glaucoma can be a devastating eye disease if it goes untreated. It is the leading cause of irreversible blindness in the world. The management of glaucoma has come a long way over the past several decades. A lot of this is due to advancements in glaucoma technology. Specifically, technological advancements in the way we monitor glaucoma changes over time as well as early detection of the disease. There are several key pieces of equipment that help us monitor and adjust treatments in the management of glaucoma.
Visual field testing helps us monitor exactly how much of the patients visual field has been lost or damaged. Baseline visual fields and the monitoring of visual fields over time are crucial in the management of the disease. Visual fields can be tested by confrontation, tangent screen or Goldman field testing, or by automated perimetry. Confrontation field testing is helpful for very large losses of visual field but not for small losses or change over time. Tangent screen and Goldman field testing involves human testers. This is very labor intensive and highly dependent on the skills of the test administrator. Automated perimetry involves the use of visual field machines. These visual field machines have basically replaced the older tests. In their earlier forms they would often take an extremely long time for a patient to complete. The newest visual field machines can now map out a patient’s field of vision in a couple of minutes per eye and are extremely reliable. The new machines also have new modalities that have the ability to catch early disease long before the old machines could. One of these is Sita-SWAP technology. This is Short Wavelength Automated Perimetry. It tests with a blue light against a yellow background. This is different than traditional field testing which tests a white light against a white background. The blue light on a yellow background can catch very early loss of vision from glaucoma or other diseases. The earlier visual field loss is identified the better we are able to treat the disease. Time is a key factor in both the detection and management of glaucoma.
Nerve fiber and optic nerve analysis is another very useful tool in the detection and management of glaucoma over time. There are many machines now available to analyze the nerve fiber layer of the retina and the optic nerve in the eye. In glaucoma the nerve fiber layer of the retina and the optic nerve lose tissue over time. The machines available today are able to analyze how much of these tissues have been lost and can map out that loss. One of the best machines to do this is the OCT. OCT stands for Optical Coherence Tomography. It uses near-infrared light to measure the nerve fiber layer of the retina around the optic nerve and the optic nerve tissue itself. The measurements from the OCT can be compared against normative databases. They also can be used to compare the patient’s own measurements to themselves over time. This is very beneficial when managing the disease.
Glaucoma testing is a critical part of the detection and management of glaucoma. The technological advancements in visual field testing and nerve fiber and optic nerve analysis have improved our ability to diagnose and treat the disease significantly. It is important however to view these tests in light of other clinical information and tailor treatment for each individual patient.