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What is the retina? |
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Retina is the neural layer at the back of the eye that transforms luminous energy of the image received by the eye to neural energy transmitted ahead to the brain. In terms of a very common comparison, the eye being the camera the retina is the film. However, the film gets exposed to light and the image is recorded on it… the retina is a dynamic structure that needs nourishment and consumes energy. |
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What is Retinal Detachment? |
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Movement of retina from its usual location is called retinal detachment. It usually signifies the separation of the pigment layer from the sensory layer. This cuts the retina off from its blood supply and nutrition. The retina will degenerate and lose its ability to function if it stays detached long enough. |
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What is a retinal tear? |
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The retina may tear at certain points due to pull by the vitreous gel. A child’s vitreous has the consistency of egg white… and is firmly attached to the retina at certain points. Usually with changes in hydration of the vitreous, it separates from the underlying retina. This separation usually is trouble and symptom free… but may cause ters in the retina at times. This allows fluid to seep under and elevates the retina from the choroid ( The pigment and vessel layer that nourishes the retina) |
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What are the zones of the retina and how are they important? |
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The most sensitive area of the retina is the Macula. This is primarily composed of cones and is responsible for the fine visual work we put our eyes to – reding, recognizing faces etc. The peripheral retina is primarily composed of rods. |
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What are the types of retinal detachment? |
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There are three
major types of retinal detachment:
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Rhegmatogenous
(Break)
A break in the sensory layer can cause
the fluid to seep in and lifts the
retina off. This is more commonly seen
in eyes weakened by HIGH MYOPIA, EYE
INJURY or PREVIOUS EYE SURGERY
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Traction
This is the kind of detachment that
develops when strands of vitreous or
scar tissue pull on the retina as
happens in DM
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Exudative
This kind of detachment results when any
inflammatory disease of the eye results
in collection of fluid under the retina
due to swelling or bleeding
Each of these would
need a different approach and comprehensive
care facility to treat the patient as a
whole and not an isolated episode of sight
threat. |
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How can you tell if you could be having a retinal detachment? |
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There is usually
quite a typical presentation of an RD:
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Who is at risk for Retinal detachment? |
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High myopes
(More than -6 correction) LASIK surgery
to correct the ‘number’ may rid one of
glasses but it does so by altering the
shape and /or thickness of the cornea.
IT DOES NOT ALTER THE RISK OF RETINAL
DETACHMENT in a ‘corrected’ eye. Even
myopes who have had refractive surgery
MUST visit an ophthalmologist for a
quarterly eye exam to track the retina.
Near sighted subjects have a 1 in 20
chance of a RD as compared to 1 in
10,000 in the normal population.
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Ocular Trauma
This, too places the eye at high risk
for a detachment by traction or bleeding
or direct trauma?
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RD in
contralateral eye This signifies a weak
retina.
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Previous eye
surgery This may be as routine as
cataract surgery!
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What can you do? |
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Retinal
detachment is an OCULAR EMERGENCY. It is
critical to report early.
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PERIODIC EYE
EXAM by an OPHTHALMOLOGIST is likely to
pick up early or predisposing changes in
the retina. The preventive steps can
then be taken and retinal detachment can
be averted.
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When at risk
avoid jerky activities like running/
weight lifting.
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Better and
timely treatment of seasonal allergies…
the force generated by a sneeze at the
nostrils is 600N/meter square
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What you may have to do… |
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PREVENTION IS THE BEST
CURE.
Unless you undergo timely and appropriate
treatment including surgery by an expert,
you may suffer irreversible visual
impairment.
This will affect your ability to perform
normal daily chores that you may be quite
used to before the visual disaster:
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Driving: Join
car pools or explore possibility of
public transport.
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Reading: Get
special glasses meant for RD patients
and keep an extra pair in your work bag
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Home safety :
Ensure that your home has no rugs that
you could trip over and is brightly lit
without and shade or shadow.
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Enlist help : Do
inform your friends and relatives seek
help in any activity that you may find
difficult to perform
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What are the tests you may have to undergo? |
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Direct and
indirect ophthalmoscopy
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Vision and
refraction
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Colour vision
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Slit lamp
examination
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Intraocular
pressure measurement
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Ultrasonography
of the eye
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Retinal
photography
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Fluoresceine
angiography
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What are the treatment options available? |
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All rhegmatogenous
retinal detachments need immediate
specialist consult atleast. All fresh RDs
MUST be treated surgically within 24-48
hours. All chronic and longstanding RDs must
be addressed within a week of diagnosis.
Exudative Rds usually resolve spontaneously
with appropriate menegement of the
underlying condition.
Traction RDs require pars plana vitrectomy
and silicone oil tamponade.
Small tears or breaks may be managed by
LASER photocoagulation or cryopexy.
True RDs require surgical intervention. This
may be in the form of
Scleral Buckle
The retinal tear is first repaired with
cryopexy, the fluid drained out and
thereafter, a soft sponge or hard silicone
band is used to indent the sclera at the
point of detachment or circumferentially in
case of major RDs. This is sutured to
reestablish adhesion between RPE and the
sensory retina and needs general anaesthesia.
Pneumatic retinopexy
A gas bubble is introduced intravitreally-
usually perfluoropropane( C3F8) under local
anaesthesia. Since gas rises, this is best
suited for superior detachments. Careful eye
and head positioning are of utmost
importance for a good “take”.
Silicone oil tamponade
This is similar to pneumatic retinopexy
escept that the tamponade material is the
silicone oil. |
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What can you expect after
the surgery? |
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Strict head and
eye positioning will be required in the
immediate postoperative period and is
critical for the result.
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The “curtain”
that got you to the doctor in the first
place may not immediately disappear. As
the retina regains its perfusion and
heals, the curtain gradually fades and
the vision may clear significantly
depending upon the severity and the type
of RD and the timely intervention.
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Time of surgical
intervention is of critical importance
and cannot be overemphasized. The nature
of all RDs is to progress to become
total within 6 months if left untreated.
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Unfortunately,
all retinas may not reattach. If such is
the case, the eye is likely to continue
to deteriorate and ultimately become
blind.
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