| |
The clear, jelly-like tissue
in the center of the eyeball is called vitreous humor, or simply
vitreous. Some problems in the eye can be helped by removing this
tissue. In young people, vitreous rests snugly against the retina,
and as the body ages, the vitreous can liquefy in parts and undergo
involution, such that the edges will fall in towards the center
of the eye. The occasionally exerts traction on the retina resulting
in a tear or even retinal detachment. If the detachment is severe,
removing the vitreous may be helpful for reducing vitreous traction.
Diabetic retinopathy is also
sometimes helped by removing the vitreous, since the this tissue
appears to facilitate the growth of abnormal blood vessels in these
patients.
Patients with uveitis often benefit
from removing the vitreous also, for two apparent reasons. It seems
to be the case that, in some patients, vitreous provides a stimulus
for ocular inflammation. At the very least, ocular inflammation
is generally easier to control in patients whose vitreous has been
removed.
Vitrectomy is major ocular surgery,
peformed in an operating room. Patients receive a local injection
to anesthetize the eye, or even general anesthesia, and the pupil
is dilated with drops. Under an operating microscope, three holes,
or "sclerotomies" are made in the eye in most cases. An
instrument is used to cut up and draw out the vitreous through one
sclerotomy, while fluid is infused into the eye through another
sclerotomy. The third sclerotomy generally is used to hold a light
pipe, which illuminates the inside of the eye so the surgeon can
see what is happening.
The eye is patched after
vitrectomy, and patients often stay in the hospital for one night.
The doctor removes the patch the next day, and a recovery period
of several weeks is anticipated.
|
|