Macular
Degeneration Introduction: As we age so does
the part of our retina that has been the most active in terms of central vision,
the fovea or
macula. For some reason, possibly due to genetic predisposition,
the macula undergoes an age-related degeneration easier in whites than in blacks,
particularly in old age. That's why this condition is also called "senile
macular degeneration". There are two forms how this degeneration can
occur, a dry
form and a wet form. With the common dry form there is an atrophic
process happening in the macula, but there are no hemorrhages or exudates. With
the wet form of macular degeneration, which is more rare, a neovascularization
(new blood vessels) process is happening in the choroidal membrane of the retina
where the pigment cells are located.
This
leads to bleeding into the retina, leakage of fluid (called exudate) underneath
the retina and a threat of retinal detachment. Signs and
symptoms: There is a visual loss without pain in both eyes with
the characteristic findings as indicated under the links "dry form"
and "wet form" above. In the beginning of this degenerative process
there might be a visual problem on only one eye, which shows up as distortion
on the Amsler's
chart. This is a squared grid of lines, which is viewed at a distance
of 35 cm (=12 inches) from the eyes. When there is a distortion of the grid, it
is time to see an eye specialist on an urgent basis. There might be pigmentary
lesions and drusen
that alarm the eye physician that macular degeneration is imminent. Diagnostic
tests: Fluorescein angiograms can be used to study
the absence
(normal finding) or presence
of a neovascular membrane formation underneath the retina. It is with the experience
of the eye specialist, the fluorescein angiograms, the visual tests, slit lamp,
direct and indirect ophthalmoscopy tests that the diagnosis of macular degeneration
is made. Treatment: If there is a neovascular network
identified by fluorescein angiograms, the eye specialist may decide to do laser
photocoagulation in order to attempt to stop further deterioration. Although the
central vision will often be lost, there is still peripheral vision outside of
the macula in the remainder of the retina. In other words, patients do not lose
all of their sight. However, they will need support services of one or more of
these support
services, which you can find under this link
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