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Macular
Degeneration and the Digital Retinal Camera
Age-related
Macular Degeneration (AMD) is the most common cause of loss
of sight in persons over the age of 60 years. Persons under
the age of 60 can also suffer from AMD, but this is less common.
In either case, it is a debilitating disease, as it causes
a loss of central vision, which is the type of vision we use
for reading, writing, and detailed vision work.
Below
is a photo illustrating what the view of the previous practice
front might look like to a person suffering from macular degeneration.
The surrounding vision, the peripheral vision, is retained
but the central vision, so important in recognition of faces
and details within a scene, is lost. This is a distressing
form of vision loss, because it can result in a tremendous
visual handicap, which can lead to a loss of confidence and
independence. At its worse, it can result in profound visual
loss, and these patients are then registered partially-sighted.
To see an animation of macular degeneration risk factors,
click on the link below:
Macular
Degeneration Risk Factors
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The
view of a person suffering from macular degeneration.
Note the central area cannot be seen while the peripheral
detail remains.
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The
digital retinal camera, while useful in photographing
all eyes, healthy or otherwise, is particularly useful in
monitoring the progression of macular degeneration. The retinal
camera, which captures pictures of the retina and instantly
produces a ‘photograph’ on a computer screen, is
useful in documenting and dating degenerative changes in the
retina. See also Ocular Abnormalities.
Digital
photography offers many advantages to the patient. For example,
the optometrist can explain to the patient a problem with
the eyes by referring to the screen picture. This can be done
at the time of the appointment, so the patient leaves the
consulting room fully aware of the health of the eyes, and
knowing the next course of action, if any is required. Also,
if a hospital referral is necessary, a photograph can be included
in the hospital referral letter, which identifies the problem
to the hospital consultant. But even if there is no need for
a referral and all looks well within the eye, a photograph
documents this. This is important for all patients, especially
those whose ocular health is slightly at risk, for example
persons with diabetes.
We
feel that the camera represents a step forward in patient
care, as inter/intra- practitioner monitoring of ocular changes
is improved, as well as inter-practice communication. For
instance, inter/intra-practitioner monitoring no longer relies
on interpretation of hand drawings but instead can be done
by close examination of photographs taken at previous visits.
And inter-practice communication improves as hospital referrals
include a photograph with the letter, which highlights the
problem seen by the optometrist. This helps the GP and the
eye specialist at the hospital to immediately see why the
patient has been referred.
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Digital
Imaging Retinal Camera
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What
does Macular Degeneration look like to the Optometrist?
Macular
degeneration is damage to the central retinal tissue. First
symptoms are a fuzziness of vision, which usually brings the
patient in for a new pair of spectacles. Examination by the
optometrist reveals minor degenerative changes in the macula,
as small degeneration changes result in significant reduction
in visual acuity, which is the ability to read down the letter
chart.
There
are two main types of macular degeneration: the dry type
and the wet type. Dry macular degeneration is the most
common type, affecting 90% of those who suffer macular degeneration.
Vision loss results from retinal deposits and tissue atrophy.
To see an animation of this type of macular degeneration,
click on the link below:
Dry
Macular Degeneration
The
second type of macular degeneration is the wet type,
also called exudative macular degeneration because loss of
vision results from the leakage of blood and fluid. Recently
there has been tremendous advances in treating this form of
vision loss, namely in the form of anti VEGF medicine. This
medicine is injected into the eye to reverse the formation
of new tissue growth, which is the cause of leaked blood and
fluid. To see an animation of this type of macular degeneration,
click on the link below:
Wet
Macular Degeneration
The
patient in the photo above has wet macular degeneration
and has significantly reduced visual acuity due to the leakage
of blood and fluid into the retina. If left untreated, the
chronic nature of this condition causes irreversible and extensive
vision loss due to scarring of the macula.
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