Macular Degeneration
and PXE.
What is macular degeneration?
What is Age-Related Macular Degeneration?
Macular degeneration, a progressive disease, is the
breakdown or damage to the macula, a part at the back of
the eye that is responsible for seeing fine details clearly.
When the macula is damaged, one experiences darkness
or blurriness in the center of vision, but the peripheral is
not affected. There are two types of age-related macular
degeneration, dry and wet:
There are a number of factors in the development of agerelated macular degeneration. Risk factors include, but are
not limited to: age (especially over 60 years), smoking,
diet, blood pressure, sunlight, genetics, and gender. As a
person ages, the macula may thin slowly: the retinal cells
die off and are not regenerated. Around 10-15% of those
diagnosed with dry type will develop the wet type, which
develops more suddenly.
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Dry: This is the most common form, where the
tissues of the macula become thinned;
Wet: This is the more damaging form, where
abnormal blood vessels grow behind the macula,
causing blood or fluid leakage, and possibly
scarring, if left untreated.
What eye functions are affected and to what extent?
The macula is a small (6mm diameter) oval-shaped yellow
spot near the center of the retina at the back of the eye.
In the center of the macula is the fovea, a small area which
contains the largest concentration of cone cells in the eye.
Thus, the macula is responsible for seeing central vision,
fine details like color, and high acuity, or sharp vision.
Loss of function varies depending on which part of the
macula is affected.
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Loss of function in the photoreceptor cells
Loss of central vision
Causes legal blindness
Damaged parts are permanently lost
What are the symptoms?
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The loss of ability to see objects clearly
Seeing straight lines as wavy
Vision is distorted
Loss of clear colors
A dark empty area in the center of vision
Objects may appear as the wrong shape or size
Difficulty in reading or seeing things up closely
Increasing difficulty adapting to low light levels
What are the implications?
Vocationally, blurred vision will affect reading and close
work activities. Avocationally, the greatest risks are with
driving. Central vision also affects the ability to recognize
faces. These implications affect a wide spectrum of
lifestyle for a patient. It is important that
accommodations are generalized from home to
school/work/hobby.
What are the common treatments?
Treatment can’t reverse the effects of macular
degeneration, but it may slow the progression of the
disease. Both juvenile and age-related macular
degeneration have new treatments in study and practice.
Treatments include but are not limited to:
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References:
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What is Juvenile Macular Degeneration, or Dystrophy?
This term is inclusive for several rare, inherited conditions.
A result of faulty genes in one or both parents, symptoms
may first appear in childhood or early adulthood. Juvenile
macular dystrophies cause the loss of central vision as a
result of damage to the macula, the most detail sensitive
part of the retina, and some affect peripheral vision also.
Examples of juvenile macular dystrophies are Stargardt’s
Disease, Best Disease, and Juvenile Retinoschisis. Other
inherited dystrophies include Sorsby’s, Pattern, Bull’s Eye,
Vitamins
Life-style changes such as diet
Regular eye exam schedule
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Kellogg . (2014). Patient Care, Macular Degeneration.
Retrieved June 28, 2014, from
http://www.kellogg.umich.edu/patientcare/conditions
/macular.degeneration.html
Montgomery, T. (2014). Anatomy, Physiology, and
Pathology of the Human Eye. Retrieved
June 28, 2014, from
http://www.tedmontgomery.com/the_eye/
Mayo Clinic Staff. (2014). Dry macular
degeneration. Retrieved June 28, 2014, from
http://www.mayoclinic.org/diseasesconditions/maculardegeneration/basics/definition/con-20075882
Mayo Clinic Staff. (2014) Wet macular degeneration.
Retrieved June 28, 2014, from
http://www.mayoclinic.org/diseasesconditions/wet-maculardegeneration/basics/definition/con-20043518
The Dictionary of Eye Terminology, 3rd Ed. Cassin B.,
Solomom, S.A.B.
Macular Societies. (2014). Dystrophies. Retrieved July
10, 2014, from
http://www.macularsociety.org/about-macularconditions/Dystrophies