Glaucoma - What is optic nerve cupping from loss of nerve fibers?
Early in the disease process of glaucoma, individual nerve fibers in the eye’s optic nerve die. This nerve fiber death results in thinning of the nerve fiber layer. As glaucoma progresses, more nerve fibers are lost, which can result in visual-field loss or blank spots, and, ultimately, loss of vision. A visual-field test, which is performed in Doctor Murphy's office, will detect these visual-field losses or blank spots when they are small.
As a result of advances in technology, a new testing method has been found to measure the thickness of the nerve fiber layer. This method uses low-power laser light in a process called Optical Coherence Tomography (OCT). An OCT scan can provide a precise measurement of the nerve-fiber layer, which improves Doctor Murphy's ability to diagnose and monitor glaucoma. An OCT scan is done in the office, and takes only a few minutes.