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Retina and vitreous surgery, laser therapy
The human eye can be divided into a front and
rear section. The front section consists of
the cornea, the anterior chamber, the iris with
pupil and lens. At the back the eye is limited
by the retina which lines the inside of the
eye. At the centre of the retina is the macula,
or yellow spot, the area of greatest visual
acuity of the eye. The space between the lens
and the retina is filled by the jelly-like vitreous.
In a healthy eye, the vitreous is in contact
with the retina, which in turn is connected
with the choroid below it. As we grow older
the vitreous shrinks and lifts away from the
retina (rear vitreous detachment). The resulting
pull on the retina can result in "flashes"
as a typical symptom. If there are thinned,
degenerative areas in the periphery of the retina,
the pull of the vitreous can cause the retina
to tear at these points leaving holes in the
retina.
This is more frequent in people who suffer from
short-sightedness than in people with normal
sight and is also hereditary.
Symptoms of this happening include the perception
of flashes or floaters, the latter being an
indication of tiny haemorrhages in the vitreous.
When fluid from the vitreous chamber penetrates
under the retina through the hole in the retina,
the retina is already detached. This can be
perceived as a growing shadow from above or
below at the side.
If the retina is not yet detached, it can be
connected around the hole in the retina with
the choroid underneath using an argon laser.
This type of laser treatment is often useful
as a prophylactic intervention in the case of
holes in the retina or thinned areas in order
to prevent detachment of the retina. This treatment
is carried out on an outpatient basis.
If the retina has become detached, an operation
has to be carried out in order to reconnect
the retina with the choroid. This is usually
achieved by stitching a silicon seal to the
sclera. Depending on the type and extent of
the retinal detachment, it may also be necessary
to surgically remove the vitreous (vitrectomy).
The retina is then restored to the right position
from the inside either with the aid of a gas
or silicon oil.
The gas is absorbed by the eye and replaced
by fluid. Silicon oil has to be removed later
by surgical means.
If left untreated, a retinal detachment can
result in blindness of the eye concerned. Vitrectomy
is also used to remove a bloodshot vitreous
humour, for example in persons suffering from
diabetes. A clouded vitreous caused by chronic
inflammation of the choroid and the ciliary
body can also be removed in this way.
Regular outpatient checkups by the ophthalmologist
are necessary after retina and vitreous surgery
which is usually carried out on an outpatient
basis.
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