Optic Nerve Analysis

Glaucoma is the leading cause of blindness in the United States. Since the disease may progress without pain or early warning symptoms, an estimated three million Americans who have the disease may not even know it. Early detection of glaucoma is now easier with new technology.

The Eye MDs have obtained a Heidelberg Retinal Tomographer (HRT), a highly advanced diagnostic instrument that helps detect glaucoma early and monitor its progression. This new technology uses a scanning confocal laser to create a three dimensional image of the optic nerve and surrounding tissue.

The laser, which is not powerful enough to harm the eye, first focuses on the surface of the nerve and captures the image. Subsequently, the laser can focus through the top layer unlike a photographic image. It obtains images deeper and deeper below the surface (similar to how a CT scan takes thin slice images of our body). The stack of 32 images is then analyzed to create a very accurate three dimensional image of the optic nerve. All of these images can be obtained in just a few seconds.

The images are used to compute things such as optic cup volume, mean retina nerve fiber layer thickness, and the area or volume of the optic nerve rim. These parameters can be helpful in diagnosing or following glaucoma patients. For example, the images can be compared to a normal population database to highlight areas of the nerve that fall outside of the "normal range". This could help in the diagnosis of glaucoma.

Changes in the optic nerve are a sign of glaucoma. As these optic nerve structural changes often precede visual field changes, one may be better able to diagnose glaucoma by closely following the optic nerve appearance. Serial HRT testing, just like serial visual field testing, can show glaucoma progression. Changes in rim or cup volume may indicate worsening of the disease.

Heidelberg states there are more than 150 peer review papers that attest to the accuracy and reproducibility of the HRT.

This technology is new and exciting. It gives us a much more accurate and objective way of following changes in optic nerve structure which we know are related to the disease process. Unlike a photograph of the optic nerve's surface, this three dimensional analysis provides significant objective data to analyze the optic nerve. We believe our patients will benefit by adding this test to serial visual field testing and eye pressure checks. Optic nerve analysis is currently covered by Medicare and many insurance companies.

The HRT laser tomographer is located in our Parkersburg office. Optic nerve analysis can be done as part of a glaucoma consultation for referred patients.

The Eye MDs have obtained this optic nerve analyzer to continue our commitment to provide "State-of-the-Art" eye care. We are truly committed to excellence in eye care.