Click the newsletter sections below to read our January 2012 Newsletter. In this newsletter, you will learn more about the Zeiss Cirrus HD-OCT and astigmatism. Also, congratulations to Dr. David Aizuss for his 25 years of outstanding service!
Congratulations to Dr. David Aizuss for 25 years of outstanding service!
Dr. David Aizuss recently celebrated his 25th anniversary at OAV. His commitment and dedication to his patients embody what we believe makes OAV a phenomenal practice.
In addition, Dr. Aizuss’ contributions to the medical community stretch far beyond his service at OAV, as he was recently elected Vice Chair on the Board of Trustees for the California Medical Association.
Dr. Aizuss has been an extraordinary mentor, caregiver, leader and partner. We are honored to have him as part of our team!
The physians of Ophthalmology Associates of the Valley recently made a major upgrade to our diagnostic arsenal when we acquired a state of the art, high-definition scanner, The Zeiss Cirrus HD-OCT. This non-invasive technology is used to help us image the back part of the eye, including the retina and optic nerve, providing us with increadibly detailed information.
By enabling us to view the retina and optic nerve with previously unobtainable detail, our ability to diagnose and manage a wide-range of retinal disorders, including glaucoma, diabetic retinopathy, macular degeneration, central serous retinopathy, macular pucker, and macular holes is greatly enhanced.
This cutting-edge diagnostic system allows our doctors to get a complete cross-sectional or 3-dimensional view of the retina using an optical measurement known as low-coherence interferometry. The technology is much like ultrasonography, except that OCT uses light instead of sound to generate images. The Cirrus HD-OCT scans an infrared light across the retina, producing retinal images of microscopic quality. It can measure distances as small as 0.05 millimeters and collect over 27 million data points per second!
With its advanced, next generation, precise algorithms, The Zeiss Cirrus OCT provides our physicians with highly detailed, high-definition maps and images of the macula and retinal structures allowing us to make the most accurate diagnosis possible.
Example 1: Glaucoma
Example 1: Optic Nerve OCT ScanDiagnosing a patient with Glaucoma sometimes can become extremely complex. The more information we can obtain about the structure and function of a patients eye the more accurate that diagnosis becomes. Besides a detailed patient history, multiple tests are performed during our evaluations. The Zeiss Cirrus OCT provides us with increadibly detailed information about the health of the optic nerve. Everyone is born with millions of cells that coat the inner lining of the retina, the back part of the eye. These cells, called ganglion cells, run together forming a cable like structure called the optic nerve. As we age, we lose these cells; however, we can lose up to thirty to forty percent of them and not have any issues. When a patient has glaucoma, they lose the ganglion cells faster than normal which may lead to visual field loss.
The Zeiss Cirrus OCT scans the optic nerve, providing us with the ability to quantify the thickness of the inner lining of the retina, the Retinal Nerve Fiber Layer. The OCT then makes cross-sectional, age matched population comparisons. This is demonstrated in the example below where the green color represents a thick (healthy) retinal nerve fiber layer, the yellow color represents a borderline thickness of the layer, and the red color represents a thin layer. The black line shows where the individual patient's scan compares to the population database. Thinning of this layer is not only used to help us make an initial diagnosis of glaucoma, but it also can be used to help monitor progression, aiding our ability to modify treatments if needed.
Example 2: Age Related Macular Degeneraion
Age Related Macular degeneration is an extremely common retinal disease that can vary in it's severity from having a minimal effect on a patient's vision to be vision threatening. In fact, it is a major cause of blindness and visual impairment in older adults. Age-related macular degeneration begins with characteristic yellow deposits (drusen) in the macula, between the retinal pigment epithelium and the underlying structures. Most people with these early changes (referred to as age-related maculopathy) have good vision. People with drusen can go on to develop advanced AMD.
The risk is considerably higher when the drusen are large and numerous and associated with disturbance in the pigmented cell layer under the macula.
The image below shows an example of a pigment epithelial detachment in a patient with macular degeneration. The Cirrus OCT provides us with the ability to evaluate this pathology in ways never before imaginable, allowing us to diagnose and potentialy treat macular degeneration with the latest vision saving therapeutic mediciations.
Astigmatism is practically universal because virtually nobody has a perfectly spherical cornea. A basketball is spherical and thus has no astigmatism whereas a football has a tremendous amount of astigmatism. A football on the ground looks very different than a football on the tee before a kickoff. This difference is the "axis" of astigmatism. Astigmatism only needs to be corrected if it causes significant blurred vision. Glasses, contact lenses, LASIK, limbal relaxing incisions, and toric intraocular lenses are all common ways of correcting astigmatism. About 35% of the normal population has 1 diopter or more of astigmatism which is certainly noticeable to patients if not corrected.
Toric contact lenses continue to improve all of the time. Now there are even a few companies making daily disposable contact lenses with astigmatism correction. Excimer lasers, which are used for LASIK/PRK, have been correcting astigmatism since the late 1990's. We can correct virtually any patient regardless of the amount of astigmatism. Not only have the astigmatism treatments improved over time, but the diagnostic abilities of these lasers to precisely detect small amounts of astigmatism have improved dramatically. Finally for many years, our practice has been implanting astigmatism correcting intraocular lenses at the time of cataract surgery (figure - above is from the website, you can call alcon and get a larger/better photo). Recently, the FDA approved lens implants that correct much higher amounts of astigmatism. These intraocular lenses enable patients to have fully corrected vision without the need for distance glasses or contacts.