Encyclopedia of Health and Medicine

124 The Eyes
eye. Recovery from uncomplicated vitrectomy
takes about two to three weeks. Complex vitrectomy,
such as when there is retinal detachment or
a macular tear, may require additional methods to
help the eye heal. Recovery from complex vitrectomy
may take several months, though usually
preserves vision and the eye.
See also AGE-RELATED MACULAR DEGENERATION;
CATARACT EXTRACTION AND LENS REPLACEMENT; CORNEA
TRANSPLANTATION; SURGERY BENEFIT AND RISK ASSESS-
MENT.
vitreous detachment The separation of the vitreous
humor, the gelatinous substance within the
EYE, from the RETINA. Vitreous detachment commonly
occurs with advancing age as the vitreous
humor thins and takes on more of a liquid consistency.
By itself vitreous detachment is harmless
and has no effect on vision, though it typically
produces FLOATERS (fragments of tissue that float
through the vitreous humor). Vitreous detachment
with accompanying flashes of light or large
numbers of floaters may indicate RETINAL DETACH-
MENT, an ophthalmologic emergency that requires
immediate treatment.
See also VITRECTOMY.
xanthelasma Deposits of fatty plaque that form
blisterlike lesions on the eyelids, usually the upper
eyelids near the corner of the NOSE. The lesions are
yellowish in color and often indicate HYPERLIPI-
DEMIA (elevated BLOOD levels of cholesterol and
triglycerides). Though harmless, the lesions can
cause the eyelid to droop, obscuring vision when
an upper lid and interfering with lid closure when
a lower lid. A plastic surgeon can remove the
lesions in a simple outpatient OPERATION, though
the lesions tend to recur, particularly when blood
lipid levels remain high.
See also BLEPHAROPLASTY; CHOLESTEROL BLOOD LEV-
ELS; LESION; SURGERY BENEFIT AND RISK ASSESSMENT;
TRIGLYCERIDE BLOOD LEVEL.