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RETINAL DETACHMENT AND RETINAL TEARS |
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Retinal detachment and related vitreous problems affect one out
of every 10,000 people each year. It is a sight threatening eye
problem that may occur at any age although it usually occurs in
middle-aged or older individuals. Surgery is often beneficial, and
if done in time, can restore good vision. At Shroff Eye Centre,
we have a dedicated team of Vitreo-Retinal specialists committed
to provide you with the best possible care to protect your vision.
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Learn about retinal detachment |
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How does the normal eye
work? |
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What is retinal
detachment? |
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What causes retinal
detachment? |
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How is a person to know
of the presence of retinal weakness, holes or tears? |
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What can be done about
floaters? |
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What causes flashing
lights? |
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Who runs a greater risk
of developing such a problem? |
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How can retinal detachment
be prevented? |
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Symptoms of retinal
detachment |
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Detection & diagnosis
of a detached retina |
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Treating retinal detachment:
Scleral Buckling
Pneumo-retinopexy
Vitrectomy
Vitreous surgery for Primary Retinal Detachment |
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What are the complications
of surgery? |
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How does the normal
eye work? |
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The
eye is like a camera in which lenses focus the picture on a light
sensitive film. In the human eye, the transparent cornea and lens
focus images on the retina, a thin light sensitive film that receives
light and changes it into electrical signals, which are then transmitted
to the brain by the optic nerve. Just in front of the lens lies
the iris ('coloured portion of the eye') with a central opening
- the pupil. This is just like the shutter or diaphragm aperture
of the camera and helps regulate the amount of light entering the
eye. The sclera ('white of the eye') is the protective outer coat
of the eye. Between the sclera and the retina lies the choroid,
which has a chiefly nutritive function. The space between the lens
and the retina is filled with a clear jelly called the vitreous
body.
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What is retinal detachment? |
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Retinal detachment is the separation of the retina from the underlying
choroid. This results in a profound loss of vision and requires
major surgery to re-attach it.
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What causes retinal
detachment? |
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Most retinal detachments are caused by the presence of one or more
tears or holes in the retina. Normal aging can sometimes cause the
retina to thin and develop holes, but more often these are caused
by shrinkage of the vitreous body (posterior vitreous detachment).
The vitreous is firmly attached to the retina in several places
around the back wall of the eye. As the vitreous shrinks with aging,
it may pull a piece of retina with it, leaving a tear or hole in
the retina. Fluid from the vitreous body then passes through the
retinal tear detaching the retina from its normal position (retinal
detachment).
Posterior vitreous detachment (vitreous separation from
the retina) is a natural process of aging and usually does not lead
to any damage of the retina. It is however more common and occurs
earlier in people who: -
Are abnormally nearsighted (high myopia);
Have undergone cataract operations (aphakics);
Have had YAG laser surgery of the eye;
Have had inflammation inside the eye.
It should be noted that there are some retinal detachments that are
caused by other diseases of the eye such as tumors, severe inflammations,
or complications of diabetes. These so-called secondary detachments
do not have tears or holes in the retina and treatment of the disease
that caused the retinal detachment is the only treatment that may
allow the retina to return to its normal position. |
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How is a person to
know of the presence of retinal weakness, holes or tears? |
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In some patients the formation of a retinal tear is preceded by
flashes of light, which are indicative of pull (traction) on the
retina. In others, the tear may break a small blood vessel in its
path causing a small hemorrhage (bleeding), with blurring of vision
and 'floaters'.
However in the majority, retinal holes are completely asymptomatic,
as they usually occur in the periphery of the retina and not in
the visually important central part. They therefore do not cause
any visual problem at all, unless they have led on to a retinal
detachment. At this stage, profound loss of vision or field occurs.
It should also be noted that 'floaters' are very commonly seen by
people who have no eye disease. They are seen as small specks, circles,
lines, clouds or cobwebs moving in one's field of vision. They are
actually tiny clumps of gel or cells inside the vitreous and cause
no harm.
Routine examination by binocular indirect ophthalmoscopy by a person
proficient in this method is the only way holes or tears may be
detected before they can cause retinal detachment.
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What can be done
about floaters? |
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Floaters can get in the way of clear vision, which
may be annoying when you are trying to read. You can try moving your
eyes; looking up and then looking down to move the floaters out of
the way. While some floaters may remain in your vision, many of them
will fade over time and become less bothersome. However you should
visit your ophthalmologist if you suddenly notice new floaters because
you need to know if your retina is torn. |
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What causes flashing
lights? |
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When the vitreous gel rubs or pulls on the retina, you may see
flashing lights or "lightning streaks". If you notice the sudden
appearance of light flashes, you should visit your ophthalmologist
immediately to see if your retina has been torn.
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Who runs a greater
risk of developing such a problem? |
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People more prone to developing retinal degeneration, holes and
tears, and subsequently retinal detachment are myopes (near sighted
persons), aphakics (people who have undergone cataract surgery),
those with a family history of retinal detachment and people with
symptoms like light flashes and onset of a large number of floaters.
These groups of patients must undergo regular and thorough retinal
examination by indirect ophthalmoscopy.
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How can retinal detachment
be prevented? |
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A
careful examination of your retina by binocular indirect ophthalmoscopy
as mentioned above will be done. For this procedure, your pupils will
be dilated with eye drops. During this painless examination, your
ophthalmologist will carefully observe your retina and vitreous and
look for holes and weak areas. At this stage (i.e. retinal detachment
has not yet occurred), they can easily be closed or sealed by producing
minute scars in the retina around them, which "weld" the retina to
the choroid and prevent fluid from seeping through the hole. These
scars can be produced by the heat of a strong light source (laser
photocoagulation), or by controlled freezing (cryotherapy). Which
of these two modalities is chosen, depends on the location of the
hole and the presence or absence of cataract and vitreous hemorrhage,
and the retinal surgeon decides individually for each case after a
thorough examination. Both cryotherapy and photocoagulation are usually
carried out as an outpatient procedure. As the treatment is from the
surface of the eye, no invasive surgery is involved. |
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Symptoms of retinal
detachment |
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Some
retinal detachments may begin without noticeable floaters or light
flashes. In those instances, patients may notice a wavy or watery
quality in their overall vision or the appearance of a dark shadow
in some part of their side vision. Further development of the retinal
detachment will blur central vision and create significant loss
of sight in the eye unless the detachment is repaired.
A few detachments may occur suddenly and the patient may experience
a total loss of vision in one eye. Similar rapid loss of vision
may also be caused by bleeding into the vitreous when the retina
is torn.
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Detection & diagnosis |
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A detached retina cannot be viewed from the outside of the eye.
Therefore, if the above symptoms are noticed, an ophthalmologist
should be visited as soon as possible. Again, binocular indirect
ophthalmoscopy through dilated pupils is essential to thoroughly
examine the retina. Other special instruments including contact
lenses, slit lamp and ultrasound may also be used.
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Treating retinal
detachment: |
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If the retina has become detached and the detachment is too large
for laser treatment or cryotherapy alone, surgery is necessary to
"re-attach" the retina. Without some type of retinal re-attachment
surgery, vision will almost always be lost.
Scleral
Buckling
The traditional surgery for retinal detachment is scleral buckling
and is performed in the operation room under local or general anesthesia.
In this process, after cryotherapy is done to seal the retinal tears,
a piece of silicone plastic is sewn onto the outside wall of the
eye (sclera) over the site of the tear. This pushes (buckles) the
sclera in toward the retinal tear and holds the retina against the
sclera until scarring from the cryotherapy seals the tear. This
procedure is usually combined with placement of an encircling silicone
band around the circumference of the eye to lessen the pulling of
the vitreous on the retina. The surgeon may also drain fluid from
underneath the retina and place a gas or air bubble into the vitreous
cavity. These buckles and bands are left permanently and are not
visible from outside. Success rates for re-attaching the retina
with scleral buckling are approximately 90-95%.
Pneumo-retinopexy
This is another type of surgery for re-attaching the retina. Instead
of placing a buckle after cryotherapy, the surgeon injects a gas
bubble inside the vitreous cavity of the eye. The patient is instructed
to keep his or her head in a specific position so that the gas bubble
seals the retina tear by its surface tension effect. Circulation
of fluid through the tear stops and the retina is re-attached.
Vitrectomy
Occasionally, retinal detachment is so complicated and severe that
it cannot be treated with either standard scleral buckling surgery
or pneumatic retinopexy. Moreover scleral-buckling surgery fails
approximately 5% to 10% of the time because excessive scar tissue
grows on the surface of the retina. This scar tissue is very bad
for the eye. It pulls on the retina, causing it to re-detach. Retinal
re-detachment usually occurs four to eight weeks after the initial
surgery. The vitreous pulls on the retina, detaching it from the
back wall of the eye. The scar tissue also puckers the retina into
stiff folds, like wrinkled aluminum foil. This condition is called
proliferative vitreo-retinopathy (PVR).
The only way to unfold and re-attach the retina is to cut away
the vitreous and remove the scar tissue with vitrectomy surgery
and then re-attach the retina. The surgeon uses a fibre-optic light
to illuminate the inside of the eye and a variety of instruments
(scissors, forceps and laser probes). The vitreous gel is removed
as well as abnormal scar tissue, and replaced with fluid or air.
Sometimes the natural lens or a previously existing intraocular
lens (IOL) may have to be removed if the case is complicated. The
holes and tears are sealed with laser, and fluid under the retina
is drained. At times, vitrectomy is combined with placement of a
scleral buckle. Often air, gas or silicone oil is placed in the
vitreous cavity to hold the retina in place. If silicone oil has
been used, it has to be removed at a later date as a separate surgical
procedure.

Removing the vitreous and especially the scar tissue from the surface
of the retina is a delicate process that requires the surgeon to
lift and peel strands of scar tissue away from the retina. The surgery
may take many hours in severe cases.
If the retina is successfully re-attached, the eye will recover
some sight, and blindness will have been prevented. However, the
degree of vision that finally returns up to six months after successful
surgery depends upon a number of factors. Unfortunately, success
in re-attaching the retina (anatomic success) does not always translate
into marked visual improvement (functional success). This is because
of permanent damage to fine vision cells of the macula. In general,
there is less visual return when the retina has been detached for
a long duration, or there is a fibrous growth on the surface of
the retina. It should be clearly understood that often the purpose
of surgery for PVR is to give the patient an eye that would have
some supporting vision and could serve as a "spare tyre", if the
other eye ever loses vision entirely.
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Vitreous surgery
for Primary Retinal Detachment |
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Vitreous surgery is now often undertaken for primary detachments
when the tears are very large or placed very far back (posteriorly)
on the retina, when there is a macular hole causing detachment,
or if there is blood in the vitreous blocking a clear view of the
retina. Success rates for these cases are much better with vitrectomy
than with scleral buckling alone.
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What are the complications
of surgery? |
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Even though the surgery for retinal detachment is generally successful,
certain complications can occur. They include drooping of the upper
lid and double vision, which are temporary. Serious complications
include infection, bleeding severe enough to interfere with vision,
glaucoma and cataract formation. However, these complications are
very infrequent. Retinal re-detachment is the most commonly occurring
problem. If this occurs, your surgeon will discuss the chance that
a re-operation will successfully re-attach the retina. It is important
for the patient to know that surgery may fail due to complications,
or simply due to the progressive nature of the retinal disease.
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For further information consult The Vitreo-Retinal
Service at Shroff Eye Centre |
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