Macular Degeneration/Dystrophies

bar3.gif (4740 bytes)

NEW   Amazing New Movie on Macular Degeneration

 

The Many Visual Problems of Macular Degeneration

Richard L. Windsor, O.D., F.A.A.O.
Laura K. Windsor, O.D., F.A.A.O.
Published in Vision Enhancement Journal

          

Patients are diagnosed daily with macular degeneration but few patients are adequately counseled on how their vision will be affected. Vision loss from macular degeneration is much more than just a loss of visual acuity. It is important that we counsel these patients on the variety of visual problems they will encounter.

Decrease of Visual Acuity:  “The sharpness of my vision is decreasing!” The macula is the center of our vision and when functioning properly provides our sharpest vision. In macular degeneration, this area is damaged and visual acuity of 20/20 is no longer possible. The surrounding retina can be used, but it is not as sensitive as the macula.

Visual Distortion: “I see wavy words, and the letters vary in size and look like they are distorted like in a funhouse mirror.” Damage to the retina may result in distortion and wavy vision due to the stretching and distortion to the retinal layers. Imagine you are projecting slides onto a screen when someone wrinkles the screen.

Come and Go Vision: “Now I see it. Now I don’t.” Macular Degeneration patients develop small areas of vision loss or blindness. They may see an object when it falls on the peripheral retina. Then as they attempt to look straight at the object, the image falls inside the blind spot and it disappears. During reading, parts of the words may fall inside the blind spots, causing parts of the word to suddenly disappearing.

Eccentric Viewing: “ I can see you better if I don’t look at youPatients must look away or turn their head to see well. This is called eccentric fixation, and it is a simple way to place the image on the peripheral retina, which is not damaged by the degeneration. Family and friends may mistakenly think the patient is not looking at them.

Photostress:  “When I come in out of the sun, I don’t see well. Things look dark.” Photostress is a term used to describe beaching out of the chemicals in the rods and cones. These chemicals are created to react to light and thus create vision. Outside in bright sun, the light exposure uses up the chemicals. Unfortunately, the damaged retina may be unable to rapidly produce new chemicals and vision may seem to decrease or dark spots may appear. This is the same process we all experience when someone takes a flash picture of us, and we see a dark afterimage for a short period. Unfortunately, in macular degeneration the spot or decrease in vision may last much longer.

Photophobia: “Bright lights seem to bother me!” General light sensitivity may increase in patients with macular degeneration. Some patients are unable to tolerate bright lights in their home. Due to this photophobia, patients usually begin wearing sunglasses to help cope with the bright lights. When scars form in the retina they serve as reflectors to scatter light back off the retina causing further intolerance to bright lights.

Better Vision at Night: “I see much better at night!” The majority of the rod cells are located in the peripheral retina and are thus unaffected by macular degeneration. Rod cells function in lower levels of light allowing the patient to have better vision.

Color Vision: “I no longer see colors as well!” The macula has the highest concentration of cones, the cells that provide color vision. Thus with the degeneration of the macula, it results in damage to the cone color cells. Patient still see colors but color perception may become more and more impaired in advanced macular degeneration.

The Paradox of Peripheral Vision Sensitivity:  “I see a tiny speck of paper on the floor, but I can’t see to recognize faces.” The peripheral retina is very sensitive to small objects and relative motion. With the central retina damaged, the patient may not be able to see faces straight ahead while seeing stars, lint on a shoulder or speck of paper on the floor, because they are picked up in the peripheral retina or side vision. If they try to look straight at the object, it may disappear just as words or other objects do. Family members often mistake this ability as an indication that the patient can see better than he or she claims.

Visual Hallucinations / Charles Bonnet Syndrome: “I see things that I know are not there! Am I crazy?” Visual hallucinations may occur in any patients with severe vision loss. Patients are often afraid to mention them for fear someone will think they are crazy. These arein the vast majority of cases not psychotic hallucinations, but are related to the brain misinterpreting the distorted image. This condition is known as Charles Bonnet Syndrome, and has been reported in the literature for over 200 years. Bonnet, Swiss naturalist, first described this as he observed in his grandfather.

Depth Perception:  “My depth perception seems impaired!” Depth perception is a very fragile visual function. Any decrease in vision may disrupt ocular depth perception. Two full functioning eyes are required for ocular depth perception. Threading a needle and other skills that require depth perception may become difficult.

Good Days and Bad Days:  “Some days I just don’t see well.” Patient often describe have some days when their vision is worse. This may be caused by light conditions, general health fluctuations and/or fluid changes in the retina.

I hope this list will help those suffering from macular degeneration and those working with ARMD patients to better understand the complex set of vision problems associated with macular degeneration.

 

 

Links Related to Macular Degeneration

 

Condensered.gif (846 bytes)Macular Degeneration Partnership - The Macular Degeneration Partnership is a coalition of patients, families,researchers, clinicians and leaders in vision and aging. Our mission is to provide accurate and timely information on age-related macular degeneration.

Condensered.gif (846 bytes) The Macular Degeneration Network - is an educational web site, filled with pictures and illustrations for patients with macular degeneration and the health professionals who care for them. It includes links for free literature searches and a Who's Who - physician finder.


Condensered.gif (846 bytes) Macular Degeneration Support, Inc.  - "Information and support for people who are affected by macular degeneration
and related diseases of the retina. This site is also available in
large-print book form for those without computer access."

Videos from MD Support Information for patients and families.

 Condensered.gif (846 bytes) Learning to Live with Low Vision

    Macular Degeneration: the Inside Story:     The Task of Living with Central Vision Loss


Condensered.gif (846 bytes)
Macular Degeneration International
- Macular Degeneration International (MDI) is a special non-profit organization dedicated to serving the needs of persons with early onset (juvenile) or late onset (age-related) macular degeneration.

Condensered.gif (846 bytes)Macular Degeneration Foundation Eyesight Informer   The Macular Degeneration Fondation arose out of the need of its founder, Ed Aleksandrovich, to learn as much as he could about macular degeneration after he was diagnosed with it. Initially, he set up the Macular Degeneration Foundation to make it easier for others to find such information.

 

Condensered.gif (846 bytes)Macular Degeneration The Complete Guide An excellent book on macular degeneration. 

Condensered.gif (846 bytes)List of Clinical Research Trials on Macular Degeneration

Condensered.gif (846 bytes)Age-Related Macular Degeneration Information for Patients from the National Eye Institute

Condensered.gif (846 bytes)The Association for Macular Disease  - Macula Foundation   The Association for Macular Disease, Inc. is an entirely volunteer, not-for-profit corportaion. We are a national support group, solely concerned with the problems of individuals and families who are endeavoring to cope with both the practical and emotional problems brought about by macular degeneration


BulletMacular Degeneration Fact Sheet   The Schepens  (Harvard) is devoted to the study of eye disease, visual dysfunction, and blindness. To work toward a cure for macular degeneration, The Schepens studies the anatomy, physiology, and development of the retina at the tissue, cellular and molecular levels in both healthy and diseased eyes. Laboratory and clinical researchers work closely together to devise new strategies in our fight against macular degeneration.

Condensered.gif (846 bytes)Don't Lose Sight of Age-Related Macular Degeneration Don't Lose Sight of Age-Related Macular Degeneration Iformation for People at Risk, information from the National Institute of Health

Condensered.gif (846 bytes)Indocyanine green & fluorescein angiography  A discussion of diagnostic dye testing in ARMD from the Vitreous Retina Macula Consultants of  New York. Fluorescein and indocyanine green angiography are diagnostic tests which use special cameras to photograph the structures in the back of the eye. These tests are very useful for finding leakage or damage to the blood vessels which nourish the retina (light sensitive tissue).

Condensered.gif (846 bytes)Age-Related Macular Degeneration—Information for Patients This pamphlet is designed to help people with age-related macular degeneration and their families better understand the disease. It describes the causes, symptoms, diagnosis, and treatment of age-related macular degeneration.

 

NEW   Amazing New Movie on Macular Degeneration

 


back.gif (3012 bytes)