Macular+Degeneration+(Benign)

Other factors that have been found to be associated are: - Dim, fuzzy, or less sharp vision. - Reading requires more light than usual. - Objects appear distorted or smaller. - Blind spot appears in vision and does not go away. - Straight lines appear wavy or curved. - Loss of central vision. 3 ||  Figure 1.1 Eye. 3 || **Age related Macular Degeneration (AMD)** - Happens slowly and gradual - Patient may not notice changes in vision until it starts to affect daily activities like reading and driving. - Symptoms are mild at first ,but may become severe. **Wet Age Related Macular Degeneration (Wet AMD) -** Less common. 1 in 10 Patients with AMD develop wet AMD. - Cause by blood and fluid leaks under the macula. - Vision loss develops rapidly. - Vision loss is severe and always permanent. 3 ||
 * ​Epidemiology: || "Age-related macular degeneration is the leading cause of severe blindness in the United States today." As a person ages, their chances of getting the condition increase. The disease afflicts 11% of patients between the age of 65 and 74 and 28% of patients older than 75. 1 ||
 * Etiology: || Although the exact cause of macular degeneration is unknown, there are some ideas that there are some environmental factors that may play a role as well as likely being genetically inherited. It often tends to run in families and studies of twins showed that genetic factors play a signigicant role in the cause. It is thought that there may be a wide variety of different genes and proteins associated with wet and dry macular degeneration.
 * Age--likelihood increases with age
 * Race--"more common in whites but occurs in all races."
 * Pigmentation--more common in lighly pigmented people
 * Iris color--"As a corollary of skin pigmentation, people with a more lightly colored iris are more likely to develop some forms of macular degenteration."
 * Gender--women seem to have a greater risk
 * Smoking--a well-established risk factor for both forms.
 * Obesity and sydrome X, Metabolic sydrome
 * <span style="color: #008000; font-family: 'Times New Roman',Times,serif; font-size: 110%;">Sleep apnea--"may be associated with macular degeneration independent of the obesity risk factor.
 * <span style="color: #008000; font-family: 'Times New Roman',Times,serif; font-size: 110%;">Sunlight exposure--"Those with lifelong outdoor careers or hobbies as well as those living near the equator and at high altitudes are at greater risk."
 * <span style="color: #008000; font-family: 'Times New Roman',Times,serif; font-size: 110%;">Medications--"some medications like Fosamax for osteoporosis may predispose to macular degeneration."
 * <span style="color: #008000; font-family: 'Times New Roman',Times,serif; font-size: 110%;">"high degrees of myopia may be associated with age-related macular degeneration or a similar condition called myopic degeneration."
 * <span style="color: #008000; font-family: 'Times New Roman',Times,serif; font-size: 110%;">Family history--other than age, seems to be the most important risk factor. <span style="color: #008000; font-family: 'Times New Roman',Times,serif; font-size: 80%; vertical-align: super;">2 ||
 * Signs & Symptoms: || <span style="color: #0000ff; font-family: 'Times New Roman',Times,serif; font-size: 110%;">Symptoms of Macular Degeneration include:
 * Diagnostic Procedures: || <span style="color: #0000ff; font-family: 'Times New Roman',Times,serif; font-size: 110%;">Macular Degeneration can be detected and diagnosed during a regular eye exam. The doctor will start with past medical history. Central vision will be checked and an a ophthalmoscopy will be used to look at the inside of the eye. See diagram 1.1. The Doctor looks at the retina and macula for signs of AMD. AMD is nerve damage to the macula. White yellowish spots on the macula are early signs of AMD. Blood or fluid in the macula are indications of wet AMD. <span style="color: #0000ff; font-family: 'Times New Roman',Times,serif; font-size: 88%; vertical-align: super;">3
 * Histology: || <span style="color: #0000ff; font-family: 'Times New Roman',Times,serif; font-size: 110%;">There are two types of Macular Degeneration:
 * Lymph Node Drainage: || <span style="color: #008080; font-family: 'Times New Roman',Times,serif; font-size: 110%;">Lymph node drainage is not a concern with macular degeneration as it is a condition due to damage of the retina. ||
 * Metastatic Spread: || <span style="color: #008080; font-family: 'Times New Roman',Times,serif; font-size: 110%;">Metastatic spread is not possible with this benign condition. It is a condition that effects the eye only. ||
 * Grading: || <span style="color: #ff00ff; font-family: 'Times New Roman',Times,serif; font-size: 110%;">There is no universally agreed upon grading system. ||
 * Staging: || <span style="color: #ff00ff; font-family: 'Times New Roman',Times,serif; font-size: 110%;">"All wet AMD is considered advanced; however, the dry form of AMD has three stages:
 * <span style="color: #ff00ff; font-family: 'Times New Roman',Times,serif; font-size: 110%;">Early AMD - patients have several small drusen or a few medium-sized drusen. There is no vision loss or symptoms at this stage.
 * <span style="color: #ff00ff; font-family: 'Times New Roman',Times,serif; font-size: 110%;">Intermediate AMD - patients have many medium-sized drusen or one or more large drusen. Some people may need more light for tasks such as reading. A blurry spot may appear in the center of the visual field.
 * <span style="color: #ff00ff; font-family: 'Times New Roman',Times,serif; font-size: 110%;">Advanced AMD - patients exhibit a large number of drusen deposits and a breakdown of RPE and photoreceptor (light sensitive) cells and supporting tissue in the retina. A large blurry spot occurs in the center of the visual field and can become larger and darker, eventually causing a complete loss of central vision." <span style="color: #ff00ff; font-family: 'Times New Roman',Times,serif; font-size: 88%; vertical-align: super;">4 ||
 * Radiation Side Effects: || <span style="color: #ff00ff; font-family: 'Times New Roman',Times,serif; font-size: 110%;">The most common side effects from irradiation include: Macular scarring, subsequent abnormal vessel growth and/or hemorrhage. <span style="color: #ff00ff; font-family: 'Times New Roman',Times,serif; font-size: 88%; vertical-align: super;">4 ||
 * Prognosis: || <span style="color: #008000; font-family: 'Times New Roman',Times,serif; font-size: 110%;">"When the choroidal neovascular membrane is subfoveal, the visual prognosis is poor, with severe vision loss in more than 75% of patients at 2 years."

A study "reported results in 19 patient with subfoveal neovascular membranes due to age-related macular degeneration treated with 10 Gy at 2 Gy per fraction or 15 Gy at 3 Gy per fraction. Using patients who declined treatments as controls, the data indicated that at 12 months visual acuity was maintained or improved in 63% of patients and significant neovascular regression was recorded in 77% of treated patients. Visual acuity deteriorated in six of seven controls, and all showed progressive enlargement of membranes. There was no significant difference in outcome between the two dose regimens." An update from the same institution showed that there was "significant improvement in visual acuity and reduced subretinal scarring were reported in 35 treated eyes, compared with untreated eyes in the same patients."

Another study reported their findings comparing four different dose regimens. Of the four, "the best results were seen with 12 Gy in 2 fractions, 18 Gy in 3 fractions, or 24 Gy in 4 fractions. Stable visual acuity was reported in 21 of 30 patients treated."

A third study involved 41 patients that were all treated with 14.4 Gy in 8 fractions of 1.8 Gy each. The had a CT sim and were planned "using a unilateral oblique 6-MV photon field, half-beam blocked anteriorly to spare the ipsilateral lens and contralateral globe. Preliminary results showed subjective visual acuity to be stable in 66%, improved in 27%, and worse in 7% at 2 to 3 months after treatment." <span style="color: #008000; font-family: 'Times New Roman',Times,serif; font-size: 88%; vertical-align: super;">1 || -Laser treatment may stop or lessen vision loss in early stages of the disease. It is performed with a specific wavelength designed to cauterize the abnormal blood vessels. Argon and krypton lasers are most commonly used for treating macular degeneration. -Photodynamic therapy - A light activated drug called verteporfin is given intravenously, and a specially designed laser is used to close the abnormal vessels while leaving the retina intact. - Local irradiation to choroidal neovascular membrane: 12Gy in 2 Fx, 18 Gy in 3 Fx, 24 Gy in 4 Fx <span style="color: #ff0000; font-family: 'Times New Roman',Times,serif; font-size: 88%; vertical-align: super;">5 || Lens - 500 cGy Cornea - 5000 cGy Retina - 5500 cGy Optic Chiasm - 5000 cGy Optic Nerve - 5000 cGy Skin - 5500 cGy <span style="color: #ff0000; font-family: 'Times New Roman',Times,serif; font-size: 88%; vertical-align: super;"> 6 || References: <span style="color: #008000; font-family: 'Times New Roman',Times,serif; font-size: 110%;">1. <span style="color: #008000; font-family: 'Times New Roman',Times,serif; font-size: 111%;">Chao KS, Perez CA, Brady LW. //Radiation Oncology Management Decisions. 2nd edition.// Philadelphia, PA: Lippincott Williams & Wilkins. 1999, 2002; 679-680. 2. WebMD, Inc//. Macular Degeneration//. Available at: [] Accessed February 16, 2010. 3. Healthwise. Age related Macular Degereration symptoms web page available at http://health.yahoo.com/vision-symptoms/age-relatedmacular-degenerative-symptoms/healthwise--hwl176070.html. Accessed on Feb. 20, 2010. <span style="color: #ff00ff; font-family: 'Times New Roman',Times,serif;">4. Macular Degeneration: Potential Treatment for Macular Degeneration. 2010. Accessed February 19, 2010, from American Health Assistance Foundation website at: []. 5. E Medicine Health. Mucular Degeneration Medical Treatments. Available at: []. Accessed on: Februaury 21, 2010. 6. Washington CM, Leaver DT. //Principles and Practice of Radiation Therapy Practical Applications.// St. Loiis, Missouri: Mosby. 1997; 80-81.
 * Treatments: || <span style="color: #ff0000; font-family: 'Times New Roman',Times,serif; font-size: 110%;">-Antioxideants: Deficiencies in antioxidents (specifically zinc and vitamins A,C, and E, selenium, copper, lutein, and zeaxanthine) have been noted in some people with age related macular degeneration. Antioxidants may protect against age-related macular degeneration by preventing free radicals or unstable oxygen from damaging the retina. The wet form of age related macular degeneration is more likely than the dry form to cause significant vision loss. Different treatements of the wet form are available and may help decrease the amount of vision that is lost.
 * TD5/5: || <span style="color: #ff0000; font-family: 'Times New Roman',Times,serif; font-size: 110%;">TD 5/5 (Whole Organ)