The retina is a very thin sheet of tissue which lines the inside of the back of each eye. If you think of an eye as a camera, then it follows that the retina would be the film of a camera. The retina captures the optical image and changes it into electrical signals, which are then sent through the optic nerve to the back part of our brain (occipital cortex). The occipital cortex allows us to perceive vision. The macula is a tiny region of the center of the retina which has special nerve connections and which allows us to see straight ahead with great detail. The inside of the eye is filled with a gel which we call the vitreous humor. This sticky gelatinous substance is composed of 95%+ water.
Dr. Barone and Dr. Hansen have each had post-residency fellowship training in diseases of the retina. Among the retina, vitreous and macula disorders, we specialize in the following:
Age Related Macular Degeneration (ARMD/AMD) is the leading cause of legal blindness in patients over the age of 65 in the U.S. The macula is a small area in the center of the retina which is responsible for central, near and reading vision. In most patients with AMD, tiny deposits slowly develop directly beneath the macula called drusen. While drusen rarely cause visual loss, they are a risk factor to further problems with the macula from AMD.
Keeping control of blood pressure and cholesterol, good nutrition and avoiding cigarettes help to decrease the risk of vision loss from macular degeneration.
There are two types of AMD. Dry and Wet:
Dry AMD usually leads to less visual difficulties than wet AMD. Vision loss is due to a loss of sensitivity of the cells in the macula which may result in a slight decrease in vision and the need to have brighter light to read. Patients with dry AMD, which is at high risk of becoming wet, are often treated with a specific set of high dose vitamins. These vitamins known as the Age Related Eye Disease Study or AREDS vitamins, do not improve vision in patients with dry AMD, but have been shown to decrease the risk of developing wet AMD in patients that are at high risk by up to 19%. Since high dose vitamins can cause systemic side effects or interfere with other conditions, your retinal specialist may recommend you discuss vitamin therapy with your primary care doctor prior to beginning the AREDS vitamins.
Patients that are smokers or recent ex-smokers should not take Betacarotene (one of the vitamins in the AREDS study) because of two studies which have shown a possible increased risk of lung cancer with higher doses of Betacarotene. An Amsler grid is often used at home to monitor for visual distortion (bending of straight lines) which may signify the development of wet AMD.
Wet AMD refers to a more serious condition which involves the development of small abnormal blood vessels under the macula which can “leak” fluid, blood and fat and lead to sudden and significant loss of central vision and visual distortion. Vision loss from wet AMD is often stabilized and occasionally improves with treatment consisting of a series of intraocular injections and occasionally laser therapy treatments which are done in the office with minimal discomfort.
Diabetes mellitus is a condition that causes high levels of sugar in the blood and damages small blood vessels in the body. Long duration of diabetes and/or poorly regulated diabetes can accelerate damage to these blood vessels. When the small blood vessels in the retina are affected, the condition is known as diabetic retinopathy. Diabetic retinopathy can progress with time and has become the leading cause of legal blindness in working aged adults. In addition to treatment of the retina directly, several studies have shown that good blood sugar and blood pressure control as well as exercise and a healthy diet, can slow the progression of diabetic retinopathy and vision loss. All diabetics should have at least one yearly dilated retinal exam, even if there are no vision complaints (symptoms). If the vision becomes blurred, especially at near, (e.g. reading) or it becomes spotty, hazy, distorted or floaters develop, diabetic patients need to contact their retinal specialist for a prompt retinal exam.
Clinically, diabetic retinopathy is divided into two broad categories: non-proliferative and proliferative. Diabetic patients can develop macular edema or swelling with either non-proliferative or proliferative retinopathy. Proliferative retinopathy is a more advanced type of diabetic retinopathy that usually requires prompt laser treatment. Patients that develop macular edema can also benefit from laser treatment and/or ocular injections in many cases. Laser is used to try to dry up swelling or destroy damaged retinal tissue to create stable scarring. Sometimes advanced diabetic retinopathy requires treatment with a surgical procedure known as a vitrectomy.
It is important to realize that many patients with no macular edema and/or proliferative retinopathy have NO visual complaints and that the ideal time to treat diabetic retinopathy and preserve vision is BEFORE vision loss occurs. It is unusual to regain vision once it is lost, thereby making it critical that diabetics have routine dilated eye exams and that patients with diabetic retinopathy be followed closely and treated when indicated. It is also important that diabetics that become pregnant be followed more closely, as pregnancy can accelerate the retinopathy.