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Questions relating to Ocular Photodynamic Therapy and AMD:
What is Macular Degeneration?
Macular Degeneration affects the central part of the retina in the back of the eye. The macula is in charge of a person’Äôs central, detailed vision. For many people degeneration of the macula is part of the body’Äôs natural aging process. Other conditions may also damage the macula.
"Dry" macular degeneration is generally caused by aging and thinning of the macular layers. Vision loss is typically gradual. On the other hand, "wet" macular degeneration may result in rapid vision loss. Abnormal blood vessels in the macula can hemorrhage causing vision loss. In this event patients may notice distortion of vision, magnification of images, a blind spot, or frank vision loss. If you have any of these symptoms, please contact your eye professional immediately.
New techniques permit restoration of vision and preservation of eye sight in retina diseases that were once considered untreatable. We strive to bring to you the best laser and surgical retinal care as advances are being made.
Photograph of a healthy retina.
A person may check their macula, or central, vision by using an Amsler grid. Cover one eye, using your glasses or bifocals, and look at the central dot. Do you notice any areas of distortion on the grid? Repeat this procedure with the other eye. Periodic retinal evaluations are recommended for the early detection and treatment of eye problems, such as macular degeneration.
A person may see moving "bugs", "specks", or "see-through" clouds in their field of vision. These are called floaters. In ancient times they were called "muscae volitantes" or
"flying flies" since they appear like small flies moving around in the air. These specks are actually clumps of a jelly-like substance called the vitreous, which fills the eye cavity.
As a person ages, the vitreous gel liquifies to form debris within the eye. It may occur more frequently in near-sighted people or those who have undergone eye surgery. Although floaters may be alarming they are usually just part of the normal aging process.
Occasionally the retina, the inner layer of the eye, is torn when the vitreous gel pulls away. New, or additional, floaters may appear due to a small amount of bleeding in the eye. A torn retina can be serious and may result in a retinal detachment. An evaluation by your eye doctor is recommended especially with any sudden onset of new or an increase in the floaters or flashes of light.
Flashes are caused by the vitreous pulling on the retina. These flashes may look like streaks of light, little balls of light, or twinkles. They may appear off and on for several weeks or longer. Flashes along with new floaters, or a shadow in the field of vision may indicate a torn retina. A prompt eye examination of the retina is recommended. Retinal tears can be serious and may lead to a detachment of the retina.
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What is Diabetic Retinopathy?
Diabetic retinopathy, a complication of diabetes, is caused by changes in the blood vessels of the retina. These damaged blood vessels may leak fluid, or blood, and induce the formation of scar tissue. In untreated diabetic retinopathy the vision becomes blurred, distorted, or partially blocked.
In some cases, fluid collects in the macula, the portion of the retina responsible for detailed vision, such as reading. This problem is called macular edema. Reading and close work may become more difficult because of this condition.
"Non-proliferative diabetic retinopathy" is an early stage of diabetic retinopathy. People with this condition have altered blood vessels which leak blood and fluid. This may or may not affect the patient's sight. Clinically small hemorrhages are seen throughout the retina. These hemorrhages can come and go as the blood is reabsorbed by the ocular tissues.
"Proliferative diabetic retinopathy" describes the changes that occur when abnormal blood vessels begin growing on the surface of the retina, or the optic nerve. They grow because parts of the retina become ischemic (do not get the blood and oxygen needed to properly function). These new blood vessels grow in an attempt to compensate for the ischemia. Unfortunately, these new blood vessels can be very destructive when not treated.
Fortunately, good treatment does exist for most patients with diabetic retinopathy. Laser and surgical treatments have become the standard of care in managing diabetic retinopathy.
Treatment is most effective in the early stages of the disease process, where laser technologies are used to seal leaking blood vessels in the case of macular edema. In proliferative diabetic retinopathy, new blood vessels are growing, the laser is used to treat the area's of ischemia causing the "new blood vessels" to undergo regression.
Advanced proliferative diabetic retinopathy, and macular edema, may require a more aggressive surgical approach. When the eye cavity is filled with blood, or the jelly inside the eye is pulling on the retina, surgery sometimes becomes the best option for improving vision. An out patient procedure, called vitrectomy, may be needed to remove the vitreous and replace it with a clear solution in cases where the vision is blocked by hemorrhage.
A comprehensive eye examination is recommended as the best protection against eye damage due to diabetic retinopathy. People with diabetes should be aware of the risks of developing visual problems and should have their eyes examined regularly.
At Retina & Macula Specialists, we strive to bring you the best laser and surgical retinal care as advances are being made. Early detection of diabetic retinopathy often times yields a better prognosis for stabilizing vision. Remember, diabetic retinopathy may be present without any symptoms. Therefore, people with diabetes should schedule an eye examination at least once a year, or as advised by their medical doctor.
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What are Retinal Tears and Detachments?
Retinal tears and detachments can occur for many reasons. The two most common causes are trauma, and the pulling of the jelly material inside the eye cavity on the retina. As we get older, the jelly material in the eye liquifies and separates from the retina in a pulling fashion. This is known as a posterior vitreous retachment. This can induce a retinal tear which can lead to a detachment process. Retinal detachments are caused by retinal tears forming and allowing fluid from the inside of the eye to get behind the retina, separating it from the back of the eye. Both retinal tears and detachments can lead to eventual loss of vision if untreated. Symptoms of retinal tears and detachments are persistent flashing lights, an increase or sudden onset of floaters in the eye, and/or a darkening like veil over parts of the vision.
Treatment for a retinal tear includes laser photocoagulation, or focal cryotherapy. The goal with treatment is to create a seal around the tear preventing fluid from tracking behind the retina.
Retinal detachments most often require a surgical repair. These procedures are done on an out-patient basis. The first type of surgery is called primary vitrectomy. In this type of surgery, the jelly material inside the eye is removed and replaced with a gas which tamponods, or holds the retina in place while it heals. A laser, or freezing probe is used to seal around the retinal tear. The gas bubble, which was injected in the eye is absorbed in approximately 10-14 days, and is replaced by aqueous solution which is naturally produced in the eye. During this time, it is necessary for the patient to keep their head in a position that allows the gas bubble to stay against the retinal surface. This is very important to the success of the surgery.
Another type of surgery for a retinal detachment is called scleral buckling. A scleral buckle is placed around the eye in circular fashion, so that the retina can be held more firmly against the outer surface of the eye. Again, laser photocoagulation or focal cryotherapy is used to seal any retinal tears.
Over 90% of all retinal detachments can be repaired by surgical techniques. Unfortunately, some patients may require more than one operation. The success of a retinal detachment surgery depends on the extent, and length of time the detachment has been present. If the macula, which is the central part of the retina becomes detached the chance of significant vision recovery decreases significantly.
There are some retinal detachments that are caused by other disease processes such as severe inflammations, diabetes, or tumors. These detachment processes can be more complicated, and may require more intense therapy.
If you experience the signs or symptoms of a retinal tear or detachment it is very important to see your doctor eye immediately.
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What does Uveitis mean?
Uveitis is a term used for intraocular inflammation. There are many etiologies for intraocular inflammation, which primarily affect the anterior segment, posterior segment or both in combination. The symptoms of uveitis include redness, pain, light sensitivity, blurred vision and floaters. Depending on the tissue involved in the inflammatory process, the symptoms may vary.
Anterior uveitis is a term used to describe ocular inflammation involving the front part of the eye. Up to 70 percent of anterior uveitis occurs for unknown reasons. It can be classified as granulomatous or nongranulomatous. The granulomatous type of anterior uveitis is more likely associated with underlying systemic disease. There are many conditions that can result in anterior uveitis, and a panel of laboratory testing may help in determining the underlying cause.
Posterior uveitis is somewhat more complicated in that the underlying cause is often times idiopathic. The symptoms of posterior uveitis often include vision loss that occurs secondary to inflammation of the vitreous, optic nerve head or cystoid macular edema. Diagnostic testing is very helpful in determining the degree of inflammation and its treatability.
The standard treatment for uveitis includes the use of cycloplegics and corticosteroids. The corticosteroids can be administered topically, through a periocular injection, or systemically.
There are newer agents available in treating posterior uveitis, including cyclosporin, methotrexate, as well as diagnostic vitrectomy.
If you have known anterior or posterior uveitis and have further questions, you can contact us through our e-mail address on this web site.
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What is Transpupillary Thermotherapy
Transpupillary thermotherapy is an exciting new technique for the treatment of wet ARMD, age related macular degeneration using a broad-beam laser. The laser is used to seal leaking vessels, also known as choroidal neovascularization. It is now possible to treat these lesions with a reduced amount of tissue damage.
What is Ocular Photodynamic Therapy
The U.S. Food and Drug Administration (FDA) approved Ocular Photodynamic Therapy for treatment of patients who wet ARMD (Age Related Macular Degeneration) complicated by predominantly classic subfoveal choroidal neovascularization (CNV). Choroidal neovascularization is a complex of blood vessels that grow into the center part of the retina. These blood vessels are abnormal and have a high probability of bleeding. This results in a sudden loss of vision.
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What is wet ARMD
Wet ARMD (Age Related Macular Degeneration) destroys central vision, which is necessary for reading, driving and the recognition of faces. It is caused by the growth of abnormal, leaky blood vessels in the eye, beneath the center of the retina. These vessels leak fluid and can eventually cause scar tissue to form, impairing central vision. Vision loss can be rapid without treatment.
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How does Ocular Photodynamic Therapy work?
Ocular Photodynamic Therapy is a two-step procedure that is performed in the doctor’s office. First, Visudyne, a light–sensitive drug, is injected intravenously into a patient’s arm. Visudyne is absorbed by the abnormal blood vessels in the eye. Second, the drug is activated by shining a non-thermal, or “cold” laser at the target blood vessels. This results in a seal off of the blood vessels causing them to regress or become smaller over time.
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How many people are affected by ARMD?
Medical experts estimate that 25 to 30 million people worldwide are affected by ARMD. In addition, 200,000 people in North America and more than 500,000 people worldwide develop wet ARMD each year. ARMD is the leading cause of legal blindness in people over the age of 50.
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Can Ocular Photodynamic Therapy restore lost vision?
Ocular Photodynamic Therapy cannot restore vision lost to ARMD, however it confines the retinal damage potenially retarding the progression of the disease. It has also been found to significantly reduce damage to the retinal photoreceptors, resulting in a higher probability for rehabiliatation or success with low vision services.
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