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Stargardt's
Disease
Overview
Stargardt's disease
(also known as fundus flavimaculatus) is a type of
macular
degeneration that typically surfaces before the age of 20.
This disease causes a progressive loss of central vision of both
eyes, but does not affect peripheral vision.
Patients with
Stargardt's experience a gradual deterioration of the
retina's cone
receptor cells. Cones are concentrated in the
macula, and
are responsible for central vision and color. Over time, these
diseased cells cause a blackened hole to form in the central vision,
and the ability to perceive colors is eventually affected.
This disease is
usually an inherited, autosomal recessive disorder. In order
to pass Stargardt's to their children, both parents must carry the
recessive gene for the disease. If both patients are carriers,
each of their children has a 25% chance of developing the disease.
There is also a dominant form of Stargardt's.
Signs and Symptoms
Stargardt's is a
progressive disease. Initially, the symptoms may be mild, but
worsen over time. The progression of Stargardt's varies with
the individual. Studies show that after
visual acuity decreases below
20/40, deterioration may be rapid until visual acuity reaches
20/200. At this level, the patient's vision typically becomes
more stable.
Early symptoms
Later symptoms
-
Progressive
deterioration of central vision
-
Missing areas of
central vision
-
Central blind spot
-
Diminishing ability
to perceive colors
Detection and Diagnosis
In the early stages of
the disease, a child with
Stargardt's may have vague complaints about his or her vision.
At this point, the retina may still appear normal, making it
difficult to diagnose with a routine examination.
Over time, signs of
Stargardt's become more evident with
ophthalmoscopy. Upon
discovering the clinical signs of Stargardt's, some physicians may
order electrodiagnostic tests to study macular function, and the
patients ability to adapt to dim lighting.
Visual acuity tests, color vision
testing, and the Amsler grid are
all used to monitor vision.
If the patient
develops leaking vessels in the macula,
fluorescein angiography
may be necessary to study the retina's circulatory system and
determine if treatment is necessary.
Treatment
Unfortunately, there
is no known cure for Stargardt's. Some patients may require
laser treatment to seal leaking blood vessels in the retina.
Laser treatment is performed to reduce lost vision from leaking
vessels; however, it cannot restore vision or halt the progression
of the disease.
Low vision aids are
recommended so patients can better utilize their peripheral and
remaining central vision. These devices include: lamps,
large print, special magnifiers and telescopes. Contact
a local agency for the visually impaired for low vision and
vocational counseling.
In 1997, scientists
isolated the gene that causes Stargardt's. Mutations of this
gene, known ABCR, result in degeneration of the retina's
photoreceptor cells. Understanding the genetics of the disease
is critical in developing new therapies and treatments.
St. Luke's Cataract & Laser
Institute provides this on-line information for educational and
communication purposes only and it should not be construed as
personal medical advice. Information published on this St.
Luke's website is not intended to replace, supplant, or augment a
consultation with an eye care professional regarding the
viewer/user's own medical care. St. Luke's disclaims any and
all liability for injury or other damages that could result from use
of the information obtained from this site. |