Cataracts-What Are They? How Do You Deal With Them?
As the population ages, cataracts are becoming a growing health
concern.
A cataract is a clouding of the eye lens to such an extent that
it affects vision. The majority of cataracts develop due to the
aging process, and by age 80, more than half of all Americans
have them. However, there are also other type of cataracts:
secondary cataracts, which form after surgery for other
ophthalmic diseases such as glaucoma; traumatic cataracts, which
can develop after an eye injury; congenital cataracts; and
radiation-inducted cataracts. Cataracts can occur in just one
eye, or bilaterally.
Age-related cataracts can develop in two ways. Protein clumping
in the capsule of lens causes poor transmission of light,
leading to blurred and cloudy vision. Also, the normally clear
lens can develop a yellow or brown tint, making it difficult to
differentiate between dark colors such as dark blue and black .
Risk factors for the development of cataracts include aging,
certain diseases such as diabetes (which also causes diabetic
retinopathy), personal behavior such as smoking and alcohol
abuse, and environmental/professional factors such as exposure
to radiation or sunlight.
For instance, a study at the University of Iceland discovered
that commercial airline pilots have a 3-fold increase in
cataracts compared to non-pilots due to ionizing cosmic
radiation at high altitudes. This radiation is normally filtered
out by the atmosphere before reaching the earth. The pilots
developed nuclear cataracts, which occur in the gelatinous
interior of the lens, as opposed to cortical cataracts, which
occur in the front capsule of the lens and are associated with
UV light. The study recommended sunglasses to filter sunlight in
the cockpit as a precautionary measure to prevent any
synergistic effects of UV light, but offered no solution to the
basic problem of radiation exposure during high-altitude flights.
Cataracts can be discovered in a routine eye exam, or after the
patient complains of symptoms such as cloudy or blurred vision,
poor color perception, glare and haloes around lights, poor
night vision, double vision, or frequent eyewear prescription
changes. Some of these symptoms can also be caused by diseases
other than cataracts.
In the early stages, the symptoms of cataracts may be relieved
by stronger eyeglasses, brighter lighting, anti-glare sunglasses
and magnifying lenses. However, if the cataract formation
progresses, it may interfer intolerably with activities of
everyday living. At this stage, surgery to remove the clouded
natural lens and replace it with a synthetic one is the only
effective treatment. Surgery relieves vision problems in 90% of
cataract patients; however, many elderly cataract patients have
other ophthalmic diseases such as glaucoma or age-related
macular degeneration which also affect vision.
There are two different surgical procedures to remove cataracts.
In phacoemulsification, also called "small incision cataract
surgery", a small incision is made in the cornea, and an
ultrasonic probe is used to break up the diseased lens so it can
be removed by suction. Extracapsular surgery is more rarely
done, and in this case the surgeon makes a longer incision on
the side of the cornea and removes the core of the lens in one
piece before suctioning out the remaining pieces. Following
removal of the natural lens, an artificial lens, called an
intraocular lens (IOL), is inserted. The surgery is usually done
on an outpatient basis under local anaesthetic and sedation.
Cataract surgery is usually safe, but complications such as
infection, bleeding and retinal detachement occur in a few
patients. Other co-existing eye disorders such as severe myopia
increase this risk. Retinal detachment is a medical emergency,
and can be ignored by the patient because it causes no pain. A
post-operative patient who has symptoms of "floaters" or light
flashes must be evaluated immediately for retinal detachment,
since early treatment can prevent loss of vision.
There are protective nutritional measures against cataracts
available to everyone. In a study on nutrition and disease
performed by the Harvard School of Public Health on 50,828
nurses, it was found that women taking vitamin C supplements of
250 to 500 mg daily for a decade or more decreased their odds of
developing cataracts requiring surgery by 45%. Vitamin A also
plays a role; the same study found that women with the highest
beta-carotene and vitamin A intakes lowered their risk by 39%.
In another study, taking 400 mg of vitamin E daily reduced
cataract formation by 50%, and in a related study, it was found
that people with the highest blood levels of vitamin E had half
the risk of developing cataracts as those with the lowest blood
levels. Lutein and zeaxanthin, found in vegetable such as
spinach and kale, are also said to be protective. Trace minerals
such as zinc and selenium are essential for the function of
anti-oxidant enzymes such as glutathione peroxidase, and doctors
often add these minerals to eye-protective vitamin formulas.