Macular Degeneration and Diabetic Retinopathy Carmen Leyva Vicki Herrin Hampton Huddleston Stephen F. Austin State University

What is Macular Degeneration?

• Macular Degeneration is the progressive deterioration of the macula, the light-sensitive cells of the central retina, at the back of the eye. As the macular cells malfunction and die, central vision becomes gray, distorted and is eventually lost. Peripheral vision does not become affected.

What is Macular Degeneration? (cont.) • The macula contains the highest concentration of photosensitive cells in the retina. These cells transform light into electrical signals that are sent to the brain for processing into vision. Fine detail vision and critical color vision are located in the macula. The macula depend on nutrient diffusion from the choroid layer. Anything that interferes with this nutrient supply can lead to MD.

What Types of Macular Degeneration Do We Have?

• Most Common -Age-Related Macular Degeneration (AMD) -It typically affects people age 50+ -It is the 3 rd cause of blindness in the world accounting for 9% of all blindness (3 million persons) -Number affected is expected to double by the year 2020 as a result of aging

What Types of Macular Degeneration Do We Have? (cont.) • Less Common Juvenile Macular Degeneration (JMD)-A group of inherited disorders affecting children and younger adults.

Cystoid Macular Degeneration-The development of fluid-filled cysts or sacs in the macular region, associated with aging, inflammation, or severe myopia.

Diabetic Macular Degeneration Retinal Pigment Epithelial detachment-A rare form of wet MD in which fluid leakage from the choroid causes the detachment or disappearance of the pigmented retinal epithelium.

What Are The Forms of AMD?

1. Dry Macular Degeneration (non-neovascular) -More common with about 85% to 90% of AMD patients diagnosed with dry AMD. -Less serious -A condition where fatty tissue slowly builds up behind the retina and causes a gradual loss of visual acuity.

What Are The Forms of AMD? (cont.) 2. Wet Macular Degeneration (neovascular) -More serious -In about 10% of cases, dry AMD progresses to wet MD.

-A condition where new blood vessels grow beneath the retina and leak blood and fluid.

This leakage causes permanent damage to light-sensitive retinal cells, which die off and create blind spots in central vision.

What Are The Two Categories of Wet MD? Two categories: a.) Occult-New blood vessel growth beneath the retina is not as pronounced, and leakage is less evident; typically producing less severe vision loss.

b.) Classic-When blood vessel growth and scarring have very clear, delineated outlines observed beneath the retina; usually produces more severe vision loss.

• • • • • • • What Are the Symptoms of Age Related Macular Degeneration?

Requiring more light for reading Reduction, blurring, a blank spot, or loss of central vision while peripheral vision is unaffected Difficulty recognizing faces Visual distortions such as the bending of straight lines Images appearing smaller Changes in color perception or abnormal light sensations A decline of at least two lines in visual acuity as measured on a standard eye chart. Ex. 20/20 vision declining to 20/80

What Are the Causes of Age-Related Macular Degeneration?

• • • • • • • Aging Obesity and Inactivity Heredity High Blood Pressure (Hypertension) Smoking Lighter Eye Color Drug Side Effects

How Is Macular Degeneration Diagnosed?

• • • Although vision loss is irreversible, early detection of MD may slow the progression of dry to wet AMD.

Usually AMD is often fairly advanced by the time an ophthalmologist is consulted.

Following the diagnosis of MD, the doctor may perform additional tests to determine the location and extent of the disease.

How Is Macular Degeneration Diagnosed? (cont.) • Tests used: Eye Exam Amsler Grid Test Fluorescein Angiography Indocyanine Green Angiography (IGCA) Optical Coherence Tomography (OCT) Genetic Testing

What Is the Treatment For Age-Related Macular Degeneration?

• Dry Macular Degeneration -No treatment available to reverse Dry MD -Progression of Dry MD can be slowed by taking high doses of vitamins A, C, and E and the minerals zinc and copper

• What Is the Treatment For Age-Related Macular Degeneration? (cont.) Wet Macular Degeneration -The doctor prescribes treatment based on the location and extent of the abnormal blood vessels Treatments used: -Anti-angiogenic Therapy (injectable drug treatment -Photocoagulation (laser surgery) -Photodynamic Therapy (injectable drug treatment) -Submacular Hemorrhage Displacement Surgery

What is Diabetic Retinopathy?

• • • Diabetic Retinopathy is the most common diabetic eye disease and it is caused by changes in the blood vessels of the retina In some people with diabetic retinopathy, blood vessels may swell and leak fluid In other people, abnormal new blood vessels grow on the surface of the retina

What is Diabetic Retinopathy? (cont.) • • • • It is the 4 th cause of blindness in the world accounting for 5% of all blindness (1.8 million persons) At least 171 million people worldwide have diabetes and this number is likely to increase more than double by 2030 to 366 million After 15 years about 2% of persons with diabetes will become blind and 10% will develop severe visual loss After 20 years more than 75% will have some form of diabetic retinopathy

What Are The Stages of Diabetic Retinopathy?

1. Mild Nonproliferative Retinopathy-Earliest Stage -Microneurysms occur 2. Moderate Nonproliferative Retinopathy -Blockage of blood vessels that nourish the retina 3. Severe Nonproliferative Retinopathy -Blockage of many more blood vessels 4. Proliferative Retinopathy-Advanced Stage -Triggering growth of new blood vessels by the signals sent by the retina for nourishment

What Are the Causes of Diabetic Retinopathy?

• Blood vessels damaged from diabetic retinopathy can cause vision loss in two ways: 1. Proliferative Retinopathy-The most advanced state of the disease in which fragile and abnormal blood vessels can develop and leak blood into the center of the eye 2. Macular Edema-Fluid can leak into the center of the macula causing swelling. This can occur at any state of diabetic retinopathy, but it is more likely to occur as the disease progresses.

What Are The Symptoms Of Diabetic Retinopathy?

• • • • • • • • Often there are no early symptoms in the early stages of the disease Spots floating in vision (floaters) Blurred vision Fluctuating vision Dark or empty arenas in vision Poor night vision Impaired color vision Vision loss

How is Diabetic Retinopathy Detected?

• Comprehensive Eye Exam that includes: -Visual Acuity Test -Dilated Eye Exam -Tonometry -Fluorescein Angiogram-Only performed if treatment for macular edema is needed.

How is Diabetic Retinopathy Treated?

• No treatment is needed during first 3 stages unless there is macular edema. Important to control levels of blood sugar, blood pressure, and blood cholesterol to prevent progression.

1. Laser Surgery 2. Injection of Triamcinolone into the eye 3. Vitrectomy

Global Causes of Blindness Due To Eye Diseases, Excluding Refractive Errors 1. Cataract 2. Glaucoma 47% 12% 3. AMD 9% 4. Diabetic Retinopathy 5% 5. Corneal Opacities 5% 6. Childhood Blindness 4% 7. Trachoma 8. Onchocerciasis 9. Others 4% 1% 13%

10 Facts About Blindness and Visual Impairment 1. Worldwide, about 314 million people are visually impaired due to various causes; 45 million of them are blind.

2. 153 million are visually impaired because of uncorrected refraction errors (near-sightedness, farsightedness, or astigmatism). Almost all of them could have normal vision restored with eyeglasses, contact lenses or refractive surgery.

3. Over 85% of visually impaired people live in low- to middle-income countries.

4. 39% of all blindness is due to age-related cataract, the leading cause of blindness.

10 Facts About Blindness and Visual Impairment (cont.) 5. Cataract surgery and correction of refractive errors are among the most cost-effective health interventions.

6. Age-related causes of visual impairment and blindness are increasing, as is blindness due to uncontrolled diabetes.

7. Up to 80% of all blindness in adults is preventable and treatable. Among children, the major causes of avoidable blindness include cataract, retinopathy of prematurity (ROP), and Vitamin A deficiency.

8. Blindness caused by infectious diseases is decreasing globally due to public health action. Blinding trachoma affects 40 million people today, compared to 360 million in 1985.

10 Facts About Blindness and Visual Impairment (cont.) 9. Around 1.4 million children under the age 15 are blind. Yet approximately half of all childhood blindness can be avoided by treating diseases early and by correcting abnormalities at birth such as cataract and glaucoma.

10. For decades, the World Health Organization (WHO) has been working with global partners to eliminate the main causes of avoidable blindness, strengthening country-level efforts by providing technical assistance, monitoring, and coordination.

References

• • • • • • • • • Macular Degeneration (n.d.). Retrieved July 29, 2010 from http://www.answers.com/topic/macular-degeneration Age-Related Macular Degeneration (n.d.). Retrieved July 29, 2010 from http://www.allaboutvision.com/conditions/amd.htm

Macular Degeneration (n.d.). Retrieved July 29, 2010 from Http://www.mayoclinic.org/macular-degeneration/ Diabetic Retinopathy (n.d.). Retrieved July 29, 2010 from http://en.wikipedia.org/wiki/Diabetic_retinopathy Facts About Diabetic Retinopathy (n.d.). Retrieved July 29, 2010 from http://www.nei.nih.gov/health/diabetic/retinopathy.asp

What is Vision 2020? (n.d.). Retrieved July 31, 2010 from http://vision2020.org/main.cfm?type=WHATVISION2020 10 facts about blindness and visual impairment (n.d.). Retrieved July 31, 2010 from http://www.who.int/features/factfiles/blindness/blindness_facts/en/index.html

AMD is the commonest cause of blindness in industrialized countries http://www.vision2020.org/main.cfm?type=WIBAGERELMUSCDEG Diabetic retinopathy is responsible for 4.8% of the 37 million cases of blindness due to eye diseases http://www.vision2020.org/main.cfm?type=WIBDIEBETIC