What You Need To Know About Cataract
Surgery
When you schedule a cataract operation,
your surgeon may require that you have a medical workup first.
Since these operations are now commonly performed in an
outpatient setting, your general practitioner can order the
necessary tests. The whole operation procedure, either cataract
surgery alone or a combined cataract and filtering operation,
can take ninety minutes to perform if the case is
uncomplicated. Depending on your condition and the surgeon's
preference, you may stay overnight in the hospital or you may
go home after the operation.
During the operation, if you are having local anesthesia,
your surgeon will inject the anesthetic around your eye. It may
hurt, but the discomfort will last for only a few seconds. The
surgeon will then perform the cataract surgery. If you are
having glaucoma surgery at the same time, that will be done
immediately after the intraocular lens implant has been put in
place.
After the operation, your eye will be bandaged overnight. In
the morning, your eye will be checked by your surgeon and your
IOP measured. You will most likely be advised to take an
assortment of drops, including antibiotics to prevent infection
and steroids to reduce inflammation. You will also be given an
eye shield, a perforated plastic oval to fit over your eye, to
protect your eye when you sleep, and you will be advised not to
bend your head, lift anything heavy, or strain during bowel
movements (a stool softener can be used if necessary to prevent
this problem). Otherwise, you can assume your daily activities.
Some surgeons say you can shower; others advise against it.
Within four to five weeks, depending on how quickly your eye
stabilizes, you may then be fitted with glasses. Many
ophthalmologists prefer to implant lenses that make the eye
slightly myopic and then correct distance vision with
eyeglasses or contact lenses, especially with patients who are
already nearsighted. They have found that people who are
accustomed to viewing the world myopically don't adapt well if
their vision is fully corrected.
The decision as to what strength lens implant to use is
based on a combination of measurements, including the curvature
of the cornea, the depth of the anterior chamber, and the
dimensions of the eye itself. You have something to say about
the strength of the intraocular lens as well. You are entitled
to discuss in advance with your doctor what you feel will be
most comfortable for you.
At this stage, unfortunately, bifocal intraocular lenses are
not available, so you may decide on a reading-strength
intraocular lens with additional correction (glasses or contact
lenses) for distance. This combination feels familiar to most
nearsighted people. Some doctors and patients have opted to
have one eye fitted with a reading-strength lens and the other
with a distance lens. While this arrangement is convenient and
eliminates the need for glasses, it makes it impossible for the
eyes to converge and work together properly, which is important
for close work and depth perception.
As with any type of surgery, complications can arise with
cataract removal, and people with glaucoma may be more likely
than others to experience some problems. Pupillary block is
uncommon, but it may occur as a complication of cataract
surgery. In this condition, the aqueous fluid is unable to
squeeze through the space between the lens and the iris, and
pressure builds up, pushing the iris forward to block the
drainage channel. This can cause a dramatic increase in
intraocular pressure. Pupillary block can be corrected with an
iridectomy or iridotomy. Studies indicate that there are fewer
cases of pupillary block if extracapsular extraction is
used.
Another difficulty may occur if the intraocular pressure
decreases to a critical stage. While people who have glaucoma
want to have low intraocular pressures, too-low pressure may
result if the aqueous fluid passes from the anterior chamber
too rapidly, causing the chamber to flatten. When the chamber
is flat, parts of the eye like the iris and cornea, which are
normally kept apart by the fluid, can touch and stick together
- and that is a decidedly undesirable event. An IOP under 5 mm
Hg may be an indication that this is happening.
Bleeding may also be a problem. Any intervention into your
eye (or any other part of your body, for that matter) can cause
the disruption of blood vessels. Most often these bleeding
vessels can be cauterized or will seal themselves, but in some
cases it may take a day or so for such a situation to resolve.
In most cases it does resolve, but until the blood clears away
your vision will be blurry.
If you have a fragile cornea, something called corneal
decompensation may occur. In this condition, the cornea begins
to lose cells and is unable to regain its former shape and
consistency. This problem occurs if your cornea has a scarcity
of cells, which may result from laser treatment or the use of
medication. Glaucoma patients are more prone to this
effect.
Your eye may also react to the implanted lens material by
forming adhesions at the lens's points of contact. If the lens
is improperly positioned, chronic iritis (inflammation of the
iris) may result. If there is recurrent bleeding,
neovascularization may develop, promoting a condition similar
to the neovascular glaucomas. In some cases, a Cataract
operation can also precipitate an attack of narrow-angle
glaucoma, for with this operation there can be a slight
shifting of the parts in the eye, and these - the pupil, the
ciliary body, or even trapped air - can block the angle through
which the aqueous fluid flows.
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