In some cases, diagnostic procedures and special testing are needed to diagnose or monitor an eye problem. Our office has the following specialized instruments:
Zeiss Cirrus HD-OCT (Optical Coherence Tomography) - Recent developments in computer imaging technology allow us to easily and rapidly image the retina utilizing a three-dimensional cross-section. This revolutionary test allows us to better understand and view disease progression of the retina, macula, and optic nerve long before actual vision loss. This technology utilizes real-time information of the living eye, analogues to an in vivo histological section of retinal tissue. Images are viewed immediately, and analyzed, utilizing a database of normal outcomes of a patient's age. The tomograph image can be compared to an ultrasound, but instead of sound, the process utilizes reflected light and converts the layered image into varied identifiable colors. This technology allows us to more accurately follow disease progression, and has quickly become the standard of care for patients with documented cautions, strong family histories, or simply to monitor the effectiveness or timing of treatment.
- Retina / Macula: Technology to this point has allowed doctors to study the retina and macula with sophisticated photography, however this only provides surface analysis. OCT tomography provides a different look at the retina with a side-view or cross-section. This provides a more detailed analysis of the central retina, optic nerve and macula. In addition, it compares the data collected numerically to normal eyes of the same age. These numerical comparisons over time allow us to detect subtle changes much earlier than with past testing options.
- Also, recent studies indicate that OCT testing can identify multiple sclerosis (MS) earlier in the course of the disease than other detection methods, and OCT could also be used to track the progression of MS, according to recent articles in neurology journals. We are pleased to be able to provide our patients with this advanced level of care.
- Optic Nerve: It is now understood that glaucoma is not simply a disease of high intra-ocular pressure, but rather, a disease of the optic nerve, specifically, the vision conductive rim of the optic nerve called the nerve-fiber layer. Measurement of eye pressure is only one small part of the data collected to evaluate the total picture in regard to glaucoma. Historically, the tests utilized enabled doctors to establish the need for treatment based on eye pressure, and documented vision loss. As a result, we diagnosed the problem after vision loss had already taken place. OCT computer imaging allows us to image the nerve-fiber layer utilizing a three-dimensional cross-section. The purpose of this test is to allow us to better understand the progression of optic nerve involvement in regard to glaucoma cautions, and other conditions, affecting the optic nerve before vision loss takes place. We are pleased to be able to provide our patients with this advanced level of technology.
Corneal Topographer - Through the progression of disease surface alteration by contact lens wear, or by accidental injury, the cornea (the clear front window of the eye) may depart from a normal shape or contour. When this alteration to the cornea is subtle, testing can be performed to examine or map the corneal surface. Corneal topography uses light reflexes and sophisticated computer analysis to obtain a surface contour map. This contour map will aid in the diagnosis and treatment of corneal pathology.
- Computerization of this corneal mapping process adds sophisticated algorithms to the intricate process of understanding the complex surface of the front of the eye. As a visual aid to understanding these maps, they are reproduced in a color format to emphasize abnormalities. Corneal topography is a modern invaluable tool to assist in the diagnosis and treatment of many corneal diseases and to plot alterations in curvature due to contact lenses.
Ultrasound Corneal Pachymetry - Pachymetry is a painless ultrasonic measurement of the thickness of the cornea. In some patients corneal thickness measurements are required to more accurately determine intra-ocular pressure in glaucoma testing. Pachymetry findings are applied to a calculation scale such that eye pressure readings are possibly adjusted in relation to corneal thickness. Patients that are found to have thinner than average corneas have a higher incidence of developing glaucoma.
- In addition pachymetry is utilized when corneal swelling (edema) is suspected. Swelling of the cornea may result in reduced transparency causing cloudy vision. Pachymetry is also used to determine candidacy for refractive surgery. Thin corneas may not have enough thickness to correct refractive error satisfactorily.
Digital Retinal Camera
Your examination today utilized digital retinal image photography to map a computer-generated image of the retina. The retina is the thin multi-layered inner lining of the back of the eye responsible for sight. It can be compared to the film in conventional cameras. Images can be instantly evaluated, and reviewed, with our patients chair-side. This technology increase the quality of the retinal exam by allowing us to view almost the entire retina, which can have important implications, not only for detecting eye disease, but also in detecting and managing other medical conditions such as hypertension and diabetes. Your images are stored permanently, and used to compare with future images of your retina, in subsequent exams. Our office is pleased to provide our patients with this valuable level of care.
Humphrey Visual Field Analyzer
Perimetry (visual field testing) is one of the most important clinical functions of a complete eye examination. Perimetry refers to the testing of peripheral vision of the eye. Analysis of data from the visual field computer allows us to construct a map of the visual responses of your retina and other neurological tissues. This detailed map is called a visual field.
- Visual field testing gives the doctor essential information about major blindness-causing diseases. Field testing is a primary tool in diagnosing and monitoring glaucoma as well as many other ocular and neurological diseases. Comprehensive or threshold visual field testing allows early detection and close monitoring of the progress of these diseases, significantly enhancing the chances for successful treatment.
- Visual field testing is a fast and easy way to ensure that your eye examination includes the most sophisticated testing available. Modern computerized perimetry optimizes the chances for accurate results and effective eye care. Computer visual field testing can identify subtle problem areas long before symptoms arise or serious damage is done.
- Field Test Instruction: For most, visual field testing tends to be quite fatiguing. You will be assisted during this procedure by a member of my staff. Before the test begins, if you feel uncomfortable in any way, inform my assistant so that they can reposition the height of your chair, or the height of the instruments chin rest. Since most visual field tests take approximately 20 minutes to complete, it is very important that you are comfortable before the test begins.
- You will be instructed to look at a specific target in the center of the instrument. As you look at this target, the computer will randomly display lights of varying intensities throughout your field of vision. When you perceive a light, you will simply press a hand held button to record your response.
- As the test proceeds, keep your eye focused on central target at all times. Do not look around and don't worry, the nature of the test is such that everyone misses some of the lights presented to them during the test. There is no such thing as failing a visual field test. Just do the best that you can. This is one time where you are expected to see "spots" before your eyes.
Your eyes have been tested today utilizing our sophisticated computer called the eye computer, or auto-refractor. In less than one second, this instrument calculates the lens power necessary to correct your vision. It does this complicated calculation without asking you any questions.
- At the touch of a button the eye computer takes a numerical picture of your eye. This procedure provides us with a high degree of "objective" reliability. Your computer findings are then confirmed and refined in the normal fashion to conclude your final visual prescription.
- It might interest you to know the impressive technology of the "eye computer" was originally developed by NASA to test the vision changes of astronauts in the space program. This instrument is a fine example of how space technology has benefited our lives. Our practice is pleased to use this technology for our patients to help ensure precise vision correction.