laucoma is a progressive optic nerve disease that can eventually lead to visual impairment and blindness. The testing for glaucoma includes both evaluating the structure of the nerve tissue and testing the visual function of the eye. The Glaucoma Diagnostic Laboratory at UMDNJ currently participates in the development and evaluation of technologies and the evaluation of new treatments that are used clinically to assist ophthalmologists caring for patients with glaucoma. These include optic nerve and nerve fiber layer imaging technologies, among other glaucoma diagnostic and treatment innovations.
What would this page look like to someone with glaucoma? It might look just the same as it does to someone with healthy eyes. The early signs of glaucoma can only be detected through a careful and comprehensive eye examination. A major focus of our research is to develop and refine technologies to improve early diagnosis of glaucoma. One important component of this strategy for preserving vision is to identify those people at greatest risk for developing glaucoma.
Most people have heard of glaucoma and many know that it can be a blinding disease, but few know the symptoms. That is not surprising. Glaucoma is not painful and vision can seem normal early in the disease. It has earned its reputation as the “sneak thief of sight!” By the time you notice something is wrong with your vision, there is usually extensive and irreversible damage.
Glaucoma is a progressive disease that damages the optic nerve (Fig. 1). A healthy optic nerve conducts visual information from the eye to the brain. But when the optic nerve is damaged, vision is affected. The testing for glaucoma includes both evaluating the structure of the nerve tissue and testing the visual function of the eye. To detect glaucoma we either try to identify when an eye does not have a “normal” structure, or we need to detect subtle but real loss of nerve tissue. The challenge has been to improve our ability to detect the earliest signs of subtle but progressive loss in the optic nerve tissues.
We have established a comprehensive glaucoma diagnostic laboratory at UMDNJ—the only one in New Jersey. The focus of the laboratory has been to develop and validate the tools that are going to be used to care for patients. We typically evaluate early versions of instruments, and before they are released, we refine both hardware and software components.
Scanning laser polarimetry (Fig 2) is a diagnostic technology that we have been working with for several years. It allows us to obtain images of the nerve fibers in the retina that contribute to the optic nerve. The nerve fiber layer of the retina is only about one tenth of a millimeter thick and is very difficult to see clinically. But loss of the nerve fibers in the retina is one of the earliest signs of glaucoma. We needed a non-invasive technique to measure this microscopic structure. These nerve fibers have a measurable optical effect on polarized light that is projected in the eye. The thinner the nerve fiber layer is, the less effect it will have. This is a very appealing approach since the fibers are accessible to imaging.
Early generations of this instrument were puzzling because they worked for some patients but not for others. Eventually several research groups recognized that the cornea and other structures interfered with the measurements and that an individual correction needed to be applied for each patient. Currently, we are working with the manufacturer of the instrument and other research groups to improve the software components for better detection of progression of disease.
Another imaging technology that is helpful for glaucoma care is scanning laser topography (Fig 3). This might be thought of as a “CT scan” of the optic nerve. The device creates a 3-dimensional map of the optic nerve structure, which undergoes changes in glaucoma. One of the challenges has been for a highly skilled clinician to outline the limits of the optic nerve within the software so the computer can process the image. This year our laboratory validated a new software approach in which the computer can perform the analysis and classification of the optic nerve without operator input. This should make this technology more widely available for screening and diagnosis.
We concentrate on translational and clinical research. Diagnosis and detection of progression are essential, but once we find glaucoma, we must treat it to preserve vision. Our clinical research group is also participating in several studies of innovative medical and surgical treatments for glaucoma that may soon be available to improve our treatment options.
Dr. Robert Fechtner is a professor in the Department of Ophthalmology and director of the glaucoma division at the Institute of Ophthalmology and Visual Science at NJMS. He specializes in mechanisms of optic nerve damage in glaucoma; psychophysical testing of visual function; computer assisted imaging technologies; and ocular pharmacology. He is a member of the American Board of Ophthalmology. Dr. Fechtner is a graduate of the University of Michigan School of Medicine and completed an ophthalmology residency at Albert Einstein College of Medicine, Bronx, NY. He completed a research fellowship in glaucoma at the New England Medical Center, Boston; a research fellowship in glaucoma at Montefiore Medical Center, Bronx, NY; and a glaucoma fellowship at the University of California at San Diego.