Encyclopedia of Health and Medicine

78 The Eyes
Gradual loss of vision at middle age and
beyond may be a symptom of AGE-
RELATED MACULAR DEGENERATION (ARMD) or
GLAUCOMA. Untreated, these conditions
result in significant and permanent
vision impairments. Any decrease in
vision requires an ophthalmologist’s or
optometrist’s prompt evaluation.
The ophthalmologist can see cataracts during
OPHTHALMOSCOPY, a painless procedure for examining
the interior of the eye.
Treatment Options and Outlook
CATARACT EXTRACTION AND LENS REPLACEMENT is the
treatment of choice for nearly all cataracts. There
is no element of time-sensitivity for the surgery.
Though VISUAL ACUITY will progressively deteriorate
as the cataract enlarges, there is no permanent
harm to vision by waiting to extract the cataract.
Following cataract surgery, more than 90 percent
of people experience vastly improved vision. Some
people who are unable to receive an IOL because
of other eye conditions will need to wear a special
contact lens or eyeglasses to carry out the refractive
functions of the extracted lens. Nearly everyone
will still need reading glasses to accommodate
PRESBYOPIA.
Risk Factors and Preventive Measures
Cataracts are primarily a consequence of aging.
Cataracts also can develop as a SIDE EFFECT of longterm
STEROID use (therapeutic or performance
enhancing). Cigarette smoking, excessive ALCOHOL
consumption, and extended exposure to sunlight
(ultraviolet rays) are among the lifestyle factors
associated with early or accelerated cataract development.
There are no known methods for preventing
cataracts.
See also AGING, EYE AND VISION CHANGES THAT
OCCUR WITH; ANABOLIC STEROIDS AND STEROID PRECUR-
SORS; CORTICOSTEROID MEDICATIONS; SMOKING AND
HEALTH.
cataract extraction and lens replacement An
OPERATION to remove the LENS from the EYE after a
CATARACT (cloudy occlusion in the lens) forms and
replace it with a prosthetic intraocular lens (IOL).
Ophthalmologists can extract a cataract at any
stage of its development. The vast majority of people
who undergo cataract extraction fully recover
without complications and experience VISUAL ACU-
ITY correctable to 20/40 or better.
Surgical Procedure
Cataract extraction is nearly always an outpatient
surgery performed under local anesthetic and a
mild general sedative for comfort. There are three
surgical procedures for cataract extraction. Each
takes 20 to 30 minutes for the ophthalmologist to
complete. Many variables influence the ophthalmologist’s
choice for which to use.
Phacoemulsification The most commonly performed
cataract extraction procedure is phacoemulsification,
which requires a tiny incision
into the capsule containing the lens. The ophthalmologist
first uses ULTRASOUND to liquefy the central
nucleus (inner, gelatinous portion of the lens)
and then uses aspiration to remove it. Last the
ophthalmologist removes the cortex (outer layer
of the lens) from the capsule in multiple segments.
Extracapsular cataract extraction The extracapsular
cataract extraction procedure requires a
slightly larger incision in the capsule, through
which the ophthalmologist removes the central
nucleus of the lens intact, then removes the cortex
in multiple segments.
Lens replacement After extracting the cataract,
the ophthalmologist inserts either a monofocal or
multifocal IOL to give the eye the ability to focus.
Contemporary lens designs allow the ophthalmologist
to fold the lens, insert it into the lens capsule
through the tiny incision used to extract the
cataract, and unfold the IOL to place it in position.
BENEFITS AND RISKS OF CATARACT EXTRACTION
Benefits
restores vision
improves QUALITY OF LIFE
Risks
postoperative PAIN and swelling
(uncommon)
postoperative INFECTION
(uncommon)
RETINAL DETACHMENT (rare)
Risks and Complications
Most ophthalmologists prescribe antibiotic and
anti-inflammatory eye drops applied to the eye for
four to six weeks following surgery, and recom-