Patients come to UT Medicine retina specialist for procedure
SAN ANTONIO (June 4, 2013) — Richard Castaneda, 66, of San Antonio visits the Medical Arts & Research Center (MARC) on Floyd Curl Drive every four weeks for a treatment that helps his eyesight. A diabetic, Castaneda began seeing “snakes” in his vision, and the distortions worsened by the time of his first appointment at the MARC. “At his initial exam, he saw only fingers held up in front of him. Now, he can read small letters at a distance,” said retina specialist Gelareh Abedi, M.D., of UT Medicine San Antonio. UT Medicine is the clinical practice of the School of Medicine at the UT Health Science Center San Antonio.
Patients with vision loss caused by diabetic macular edema and other conditions are coming to Dr. Abedi for safe and painless treatment that temporarily improves their eyesight. Dr. Abedi has administered 5,000 to 6,000 intraocular injections of medications that inhibit endothelial vascular growth factor (VEGF) in the eye, preventing abnormal blood vessels from leaking fluid that obscures vision. Because of her meticulously sterile technique, no patient has contracted an eye infection.
“I hardly feel the shot when Dr. Abedi gives it to me — you just feel a little pinch,” said Castaneda, who is being treated for diabetic macular edema.
Fluid and swelling (called edema) damage the macula, a tiny area of the retina that is responsible for 90 percent of a person’s vision. The retina is a light-sensitive layer in the inner eye that receives images coming through the lens and converts them to electrical signals, which are transmitted to the brain via the optic nerve. The macula is the focal point for this activity.
Alternative to laser surgery
The medications are called vascular endothelial growth factor (VEGF) inhibitors. “Before these inhibitors we couldn’t offer patients anything except, in some cases, laser surgery, which also isn’t a permanent cure,” Dr. Abedi said. “Macugen®, the first anti-VEGF drug, was approved in 2004 for treatment of age-related macular degeneration. Avastin®, the drug that Mr. Castaneda receives for diabetic macular edema, became widely used in 2005 primarily for macular degeneration and later for a variety of macular conditions including diabetic macular edema. Currently another class of VEGF inhibitors called VEGF-trap is being tested for patients with diabetic macular edema; these can potentially improve patients’ vision for up to two to three months.”
The Avastin injection takes effect immediately and peaks in activity at two weeks. After a month, the patient requires another injection. The result is life-changing for Castaneda, whose vision recovers from 20/70 to 20/40. The improvement is three lines of vision on an eye chart.
The procedure is covered by most insurances and Castaneda submits his $30 copay per visit. “Regardless of what you have to pay, you want your eyesight,” he said.
Ophthalmic photographer Carrie Cooke captures two-dimensional images of the retina to help inform Dr. Abedi’s treatment decisions. UT Medicine, with the support of Francisco González-Scarano, M.D., dean of the School of Medicine and vice president for medical affairs, and Daniel Johnson, M.D., chairman of the Department of Ophthalmology, recently purchased two imaging suites at a cost of $300,000 that have been installed at the MARC and at the Texas Diabetes Institute, a University Health System facility on San Antonio’s West Side where Dr. Abedi also sees patients.
Technique ensures comfort
Varieties of anesthetic technique are used to ensure ultimate comfort for the patient. Dr. Abedi first places several drops of an anesthetic into the eye. Then she uses an ultra-fine-gauge needle to inject a numbing agent into the subconjunctiva — transparent tissue that covers the white part of the eye, the sclera. This is the pinch that Castaneda mentioned. The numbing agent diffuses through the area to be injected. She then cleans the entire conjunctival area, eyelashes and lids with an antiseptic. (The conjunctiva, a transparent layer over the sclera, is the eyeball’s outermost covering.) After 15 minutes, the sclera is ready for the intraocular injection, which is the Avastin in Castaneda’s case.
Diabetic macular edema is a chronic and challenging outcome of diabetes. “We always tell our patients, ‘Please control your blood sugar and blood pressure,’” Dr. Abedi said. “If they are not controlled, the fluid will return.”
In the years since VEGF inhibitors came into use, clinicians have learned that a single visit is not enough. It generally takes at least three injections — and as many as half a dozen — for patients to experience a noticeable difference in their vision.
Castaneda likes the fact that Dr. Abedi is an academic doctor who participates in conferences to educate other physicians and also to learn more about ongoing research for finding new therapies. “That gives you more confidence in your doctor,” he said.
To see Dr. Abedi and have a full retina examination, call UT Medicine at (210) 450-9400. Dr. Abedi is fellowship-trained and is board certified by the American Board of Ophthalmology.
UT Medicine San Antonio is the clinical practice of the School of Medicine at the UT Health Science Center San Antonio. With more than 700 doctors – all School of Medicine faculty – UT Medicine is the largest medical practice in Central and South Texas. Expertise is in more than 100 medical specialties and subspecialties. Primary care doctors and specialists see patients in private practice at UT Medicine’s flagship clinical home, the Medical Arts & Research Center (MARC), located at 8300 Floyd Curl Drive, San Antonio 78229. Most major health plans are accepted, and UT Medicine physicians also practice at several local and regional hospitals. Call (210) 450-9000 to schedule an appointment, or visit www.UTMedicine.org for a list of clinics and phone numbers.