What
is a RETINAL DETACHMENT?
A retinal detachment
is where the retinal lining detaches from the back wall of the eye.
This is due to a tear or a break in the lining, allowing fluid from
the vitreous jelly to leak under the retinal lining, causing the
retina to lift off. The retinal tear may occur due to trauma, or
more commonly, due to vitreous traction from the vitreous jelly
causing a rip in the retinal lining. In some cases, there may be
a family history of retinal detachment. Also, high myopia (short-sightedness)
may increase the risk of tears in the retina as the retina is thinner.
Some patients are born with an inherited weakness in the retina
causing lattice degeneration that may also pre-dispose them to a
retinal detachment.
Approximately one in
ten thousand people will suffer from a retinal detachment. Prior
eye surgery or trauma may increase the risk.
The retinal detachment
may also be associated with some haemorrhage into the vitreous jelly
and the patient may note blurred vision or a reddish or pinkish
tinge in their vision.
Symptoms of a
retinal detachment
The patient may notice
symptoms of a retinal tear or detachment, such as a sudden onset
of flashes and floaters, followed by loss of vision, with the impression
that there is a curtain moving up and down or sideways. They may
note that vision on one side of their field has decreased. The patient
may also notice that their vision is blurred.
Treatment of
a retinal detachment
Treatment of a retinal
detachment involves an operation. There are two methods that can
be used to treat a retinal detachment.
1. Scleral buckling
A scleral buckling operation
is where a reinforcing silicone band is placed on the outer wall
of the eye to close the retinal tear. This is used in conjunction
with cryotherapy which seals the retinal tear or break. Air or gas
may be injected into the eye which also helps to close the tear
or break. The scleral buckle remains in place permanently and becomes
part of the eye wall. In very rare circumstances, it may need to
be removed at a later date.
2. Vitrectomy surgery
Vitrectomy surgery involves
the removal of the vitreous jelly which can harbour factors that
cause scarring of the retina. The surgery also relieves traction
in the vitreous jelly that may have caused the retinal detachment.
Vitrectomy surgery uses microsurgical instruments inside the eye,
enabling laser treatment to seal the retinal tear or break. Special
gas is injected inside the eye to close the retinal break. This
is usually absorbed over a period of six to eight weeks. Vitrectomy
surgery is usually performed in conjunction with scleral buckling.
Scleral buckling surgery
is usually reserved for smaller retinal detachments; usually for
patients who have had no previous intraocular surgery.
Vitrectomy surgery, combined
with scleral buckling surgery is usually performed in larger or
more complex retinal detachments or in patients who have had former
intraocular surgery.
In very severe cases
of retinal detachment, where there is scarring of the detached retina,
the scar is required to be removed with microsurgical instruments
and long acting gas or special high grade silicone oil is required
to be injected inside the eye to flatten the retinal detachment.
The length of time for
surgery varies from approximately one hour for a scleral buckling
operation to one and a half to three hours for a complicated case
involving vitrectomy surgery and scleral buckling.
Anaesthesia
In most cases, vitrectomy
surgery and scleral buckling can be performed under local anaesthetic
with sedation. If required, general anaesthesia can be provided.
Success rate
The success rate for
retinal detachment surgery is approximately 90%. Approximately 10%
may require further surgery if the retina is not attached after
the first procedure. In some cases the retina may be attached initially,
but the retina may scar after about 6 to 8 weeks and re-detach.
Once the patient’s retina remains attached for 3 months following
the surgery, the incidence of further retinal detachment is much
less.
The improvement in vision
will depend on the amount of retinal detachment and the length of
duration of a retinal detachment prior to the surgery. Following
a retinal detachment procedure, normal vision may not be fully regained.
This is due to damage to the photoreceptor cells in the retinal
lining.
The vision following
retinal detachment surgery may continue to improve for up to a year
following the surgery.