Transcript Macular Degeneration Adult and Juvenile

Macular Degeneration
Adult and Juvenile
Summer 2014
Brandey Burnett, Amanda Noles, Jamie Points
What is Macular Degeneration?
Macular Degeneration is a common, painless eye condition in which the
central portion of the retina (a light-sensitive layer of tissue, lining the
inner surface of the eye) deteriorates and does not function adequately.
Types of Macular Degeneration
There are many types of macular degeneration.
•
Age-related macular degeneration (AMD) is by far the most common type.
AMD occurs as part of the body’s natural aging process
•
Another type is Juvenile Macular Degeneration (JMD). Juvenile macular
degeneration is different from AMD and is sometimes called macular
dystrophy.
As macular degeneration develops, clear, normal vision ( left) becomes
impaired by a general haziness. With advanced macular degeneration, a blind
spot forms at the center of the visual field (right).
What is Age-related
Macular Degeneration?
Age-related macular degeneration (AMD) is the leading cause of vision loss in
Americans 60 years of age or older. It progressively destroys the macula (the central
portion of the retina) impairing the central vision. It affects the sharp central vision
that is needed for seeing objects clearly. It is difficult or impossible to complete
common every day tasks such as reading, recognizing faces, and driving, however,
enough peripheral vision remains to allow other activities in daily life. It rarely causes
blindness because only the center of vision is affected. The use of magnifying devices
can often improve vision in macular degeneration to allow for reading or watching
television.
Two Forms of Age-related
Macular Degeneration
AMD occurs in two forms:
• “Dry” age-related macular degeneration is the more common type and is more
slowly progressive in causing vision loss.
• "Wet" age-related macular degeneration is less common but more aggressive in its
progression to severe central vision loss.
All people who have the dry form of AMD are at risk for development of the wet form.
Therefore, people who have the wet form had the dry form first. Currently, there is no
certain way to predict if or when the dry form will turn into the wet form.
Dry AMD can advance and cause vision loss without turning into wet AMD. Dry AMD
can also rapidly transform into the wet form by the growth of new blood vessels.
What is “dry” Age-related
Macular Degeneration?
In dry AMD, the light-sensitive cells and supporting tissue in the central
retinal area slowly break down, causing central vision to diminish over time.
This breakdown can cause a blurred spot in the center of vision. Eventually,
the blurred spot may get bigger and darker, taking more of the central
vision.. Early stages of dry AMD can be treated with high-dose formulations
of antioxidants and zinc, which may delay and possibly prevent AMD from
progressing to a more advanced stage. Once in the advanced stage, no form
of treatment can restore vision loss.
Early symptoms of dry AMD include slightly blurred vision, the need for more
light for reading and difficulty recognizing faces until very close to the
person. A symptom of more advanced dry AMD is the presence of a blurred
spot in the center of vision.
Treatment for Dry Macular Degeneration
There is currently no treatment available to reverse dry macular degeneration.
However, dry macular degeneration is usually slowly progressive and most patients
with this condition are able to live relatively normal, productive lives. Often one eye
is affected more than the other.
Once dry AMD reaches the advanced stage, no form of treatment can prevent
further vision loss. However, treatment can delay and possibly prevent
intermediate AMD from progressing to the advanced stage of severe vision loss.
The National Eye Institute's Age-Related Eye Disease Study found that taking a
specific high-dose formulation of antioxidants and zinc significantly reduces the risk
of advanced AMD. Slowing AMD's progression from the intermediate stage to the
advanced stage is helpful in reducing the progression of visual loss in many people.
What is “wet” Age-related
Macular Degeneration?
In wet AMD, abnormal blood vessels behind the retina start to grow under the
macula and leak blood and fluid, causing loss of central vision, which may occur
quickly. Treatment includes laser surgery, photodynamic therapy, and
injections in to the eye. None of these will cure the disease and loss of vision
may still progress.
An early symptom of wet AMD is the wavy appearance of straight lines. During
an eye exam, you may be asked to look at a checkerboard pattern called an
Amsler grid. When looking at an Amsler grid with one eye, patients with AMD
may notice that the straight lines of the checkerboard appear wavy or are
missing.
Treatment for Wet Macular Degeneration
Wet AMD can be treated with laser surgery, photodynamic therapy, and injections
into the eye. None of these treatments is a permanent cure for wet AMD. The
disease and loss of vision may progress despite treatment.
There are multiple drugs and devices presently in various phases of clinical trials to
both prevent and treat macular degeneration. These include new drugs to prevent
new blood vessel formation, certain anti-inflammatory treatments for the wet form
of AMD, and drug-delivery systems to reduce the need for frequent injections for
the wet form of macular degeneration. The possibility of transplantation of
transplanting healthy cells into a diseased retina is also being investigated.
What is Juvenile Macular Degeneration?
Juvenile macular degeneration is the term for several inherited eye diseases that
affect children and young adults. These diseases include Stargardt's disease, Best
disease, and juvenile retinoschisis. These rare diseases cause central vision loss that
may begin in childhood or young adulthood.
Unfortunately, there is no treatment available to prevent vision loss for these
diseases. The diseases are caused by gene mutations passed down in families. Visual
aids, adaptive training, and other types of assistance can help young people with
vision loss remain active. Researchers continue to look for ways to prevent and treat
juvenile macular degeneration (JMD).
The most common form of juvenile macular degeneration is Stargardt disease.
What is Stargardt’s Disease?
Stargardt's disease is also called fundus flavimaculatus or macular dystrophy.
Children and teens with Stargardt disease first notice a problem with their
central vision, which may be blurry, distorted, or have dark areas. It may take
longer than usual to adjust between bright environments to dark
environments. Peripheral vision remains normal, but color perception may be
affected in the later stages of the disease, despite the macula disorder. And
as the disease progresses, small blind spots (scotomas) often develop in the
central visual field.
The progressive vision loss associated with Stargardt disease is caused by the
death of specialized, light-sensitive photoreceptor cells in the central portion
of the retina called the macula. The retina is the layer of tissue lining the back
of the eye, and the macula is the part of the retina that is responsible for
your central vision, allowing you to see fine details clearly.
Stargardt’s Disease (cont.)
Vision loss from Stargardt’s Disease responds very well to magnification which
can make reading, seeing signs, faces, the computer, TV, and even driving a
possibility. There is a wide range of optical, electronic and software
magnification options to address virtually every need.
There is no cure for Stargardt disease and no treatment to slow its progression.
However, genetic treatments already are available for related conditions, and it
is likely that they will be available for Stargardt’s disease in the near future.
References
Children's Corner for Macular Degeneration. (n.d.). Retrieved July 14, 2014, from
https://www.childrenscorner.org/about-macular-degeneration
Dahl, A. (2014). Macular Degeneration. Retrieved July 17, 2014, from
http://www.medicinenet.com/macular_degeneration/article.htm
Get Smart Eyes: What is Juvenile Macular Degeneration? (n.d.). Retrieved July 15, 2014, from
http://www.geteyesmart.org/eyesmart/diseases/juvenile-macular-degeneration.cfm
Get Smart Eyes: What is Stargardt Disease? (n.d.). Retrieved July 15, 2014, from
http://www.geteyesmart.org/eyesmart/diseases/stargardt-disease.cfm
References
(cont.)
Juvenile Macular Degeneration: Stargardt's and Best Disease. (2013). Retrieved July 17, 2014, from
http://www.webmd.com/eye-health/juvenile-macular-degeneration-stargardts
Lighthouse International: Age-Related Macular Degeneration (AMD). (2014). Retrieved July 14, 2014,
from http://lighthouse.org/about-low-vision-blindness/vision-disorders/age-related-maculardegeneration-amd/
Lueck, Amanda Hall. (2004). Functional vision: A Practitioner's Guide to Evaluation and
Intervention. New York: AFB Press, American Foundation for the Blind.
Roberts, D. (2002). Types of Juvenile Macular Degeneration. Retrieved July 16, 2014, from
http://lowvision.preventblindness.org/eye-conditions/types-of-juvenile-macular-degeneration