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Chances are, if you’ve visited the Eye Institute as a patient recently, you’ve had a picture of your eye taken. Ophthalmic photography is a rapidly changing and expanding field, with new devices emerging every year to assist Ophthalmologists in treating their patients. Be it a simple fundus photograph of the retina or an ultrasound image of the entire eye, images of the eye provide vital information that can be used to effectively diagnose, and manage any number of eye disorders. However, imaging at the Eye Institute is anything but routine, thanks to a new initiative known as the Advanced Ocular Imaging Program
The number of imaging procedures being performed in clinics like the Eye Institute has risen dramatically over the past 5-10 years. Recognizing that imaging was not a fad, the Eye Institute made a decision to invest in bringing in this cutting-edge technology and leveraging it to conduct innovative research and provide improved patient care.
The idea of an imaging program originated nearly 5 years ago when Dr. Joseph Carroll was recruited to the Eye Institute, he has seen the program grow from an idea into a thriving enterprise. “When I arrived at the Eye Institute, I immediately saw the potential of this environment. Not only did we have excellent clinicians and scientists, but there was a commitment from Dr. Heuer (the chairman of the department) to support such an initiative as well as a number of local foundations and individual donors who believed in the idea and provided the crucial financial support to get it off the ground,” says Dr. Carroll.
Dennis Han, MD and Joseph Carroll, PhD are co-directors of the program. “We work together to identify areas of opportunity to improve the quality of imaging we can offer to our patients.” says Dr. Han. The Eye Institute has made over a $3 million dollar investment in the program, beginning with the recruitment of Dr. Carroll in 2006 and including the recent recruitment of Dr. Alfredo Dubra in 2011 (see page 6).
Given that imaging is such a central hub of activity in the Eye Institute, we’d like to take this opportunity to introduce our instruments and explain the value of the pictures they can provide.
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Fundus Photography
The first images of the living retina were acquired 125 years ago. Since that time, fundus photography has remained the preferred way to image the retina to document and manage a variety of retinal disorders. The major benefit of having a fundus photograph taken is that it provides an enlarged view of what a clinician can see with a hand-held device and allows for an objective record of the eye which clinicians can reference over time. These images may be most helpful in managing diseases that manifest over a long period of time such as glaucoma, nevi or diabetic retinopathy. An advanced version of the technology is also available to take autofluorescence images, which may be valuable in gauging the effectiveness of certain treatments.
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Fluorescein Angiography
A key component to diagnosis and management of many eye diseases is to determine if there are abnormalities in blood vessels that line the back of the eye in the retina. Fluorescein angiography is an imaging technique that provides detailed information about the blood vessels in the eye. Most of the other imaging techniques give important information about the anatomy of the structures of the eye, whereas fluorescein angiography gives information about the blood flow, as well.
“I use Fluorescein angiography as a tool to aid in the detection of diseases like diabetic retinopathy and vein occlusions because the images provide me with the needed information to determine if there are any blockages or leaks in the blood vessels,” commented Dr. David Weinberg.
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Color fundus photo (A) and fluorescence angiogram image (B) of a person with worsening diabetic retinopathy. The fundus photo (A) shows the optic nerve (yellow circular structure on the right), blood vessels, and a pre-retinal hemorrhage (blood) near the bottom. The fluorescence image (B) shows abnormal blood vessel growth in diabetes as seen by the leakage of fluorescence dye out of vessels on the left of the image.
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Optical Coherence Tomography
Optical coherence tomography (OCT) has revolutionized ophthalmology by becoming the go-to device for the evaluation of macular retinal disease. It allows physicians to take non-invasive, high-resolution images of the retina to visualize the different layers in cross-section. This technology allows detection of subtle areas of fluid, blood, and other abnormalities that could not be detected in a clinical exam. Because it is non-invasive and very quick to do, OCT provides a way to diagnose and track treatment responses in many diseases including wet age-related macular degeneration, diabetic macular edema, glaucoma and may also be used to survey possible complications that can occur with some systemic medications. The Eye Institute currently has 5 different OCT systems, all offering unique advantages for studying the retina.
“Recently we have been able to use OCT technology in non-clinical areas like the operating room and the neonatal intensive care unit, giving us a very safe, non-invasive way to get information that may ultimately save vision for individuals” said Dr. Kimberly Stepien, MD, a retinal specialist at the Eye Institute. “OCT is an invaluable tool in helping me provide the best care possible for my patients.
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Normal OCT – A spectral-domain OCT of an individual with normal macular retinal appearance. The small depression in the middle of the image shows a normal foveal contour of the macula.
Wet AMD – A spectral-domain OCT of an individual with wet macular degeneration. The dark space represents abnormal fluid underneath the retina tissue, displacing the retina, and causing blurred vision. The small bumps seen in the lowest layer of the image are drusen - small accumulations of debris that can be seen with macular degeneration.
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Ultrasound
When examining your eye, your doctor can usually look through the pupil to see the back of the eye. Occasionally, changes in the eye can prevent a view into the back. Other times, your eye doctor can see into the eye, but is not able to accurately measure changes in the back of the eye. When these situations occur, an ultrasound of the eyeball can be very helpful. An ultrasound measures high-frequency sound waves as they travel through the medium of the eye. The reflections (echoes) of the sound waves form a picture of the structures of the eye that clinicians can use to survey damage to the eye socket, detect foreign bodies in the eye and even diagnose conditions like retinoblastoma (cancer of the retina)
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Adaptive Optics
Adaptive optics is a unique technology and represents the cornerstone of the Advanced Ocular Imaging Program. Images taken with this equipment provide clinicians with the highest resolution images available of the retina. In fact, these images are so good, that it is possible to see individual photoreceptor cells (cones and rods). These images can be important for looking at a number of retinal diseases that impact the photoreceptors like age-related macular degeneration, retinitis pigmentosa, Stargardt disease, achromatopsia, and albinism.
Used for research, scientists at the Eye Institute are optimistic that this equipment will fill a current gap in clinical knowledge. “One of the major hurdles in detecting eye disease,” said Dr. Joseph
Carroll, PhD, “is that by the time it can be perceived by the patient or detected with standard clinical tools, significant cellular damage has already occurred.” Adaptive optics imaging tools provide an opportunity to understand eye disease on the most basic level with the ultimate goal of detecting and treating disease BEFORE vision has been lost.
In its first year of existence, the Advanced Ocular Imaging Program has grown substantially adding both people and equipment. Greatly aiding in our clinicians ability to diagnose and treat disease, this technology has also contributed data for 12 scientific publications in the past year. These publications include one heralded as “historic” by the Optical Society of America - the first ever pictures of the rod photoreceptors which gained the privilege of gracing the cover of a recent edition of the journal Biomedical Optics Express (seen below).
The program as it stands today would not have been possible without the vision and foresight of generous foundations including Research to Prevent Blindness, Foundation Fighting Blindness, RD and Linda Peters Foundation, Gene and Ruth Posner Foundation, Hope for Vision, and the Karl Kirchgessner Foundation, as well as dozens of individuals who donated to the development of this program.
This program will continue to grow and develop as new technologies emerge. If you are interested in supporting the Advanced Ocular Imaging Program, or would like to know more about imaging at the Eye Institute, please contact Diane Bishop at 414-955-7821 or dbishop@mcw.edu.
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Adaptive optics images of the living human retina. Image A is from a patient with normal vision, each little circle is an individual cone photoreceptor cell. Image B is from an individual with a red–green color vision defect, the black holes reveal a patchy loss of healthy cones. (Scale bar is 50 mm.)
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