by Elizabeth Peterson, MFA
Anatomy and Physiology
The eye is like a camera. It has a pupil that allows light to enter, an iris to determine how much light to admit, a lens to focus the light, and a retina onto which an image is focused.
When you look at an object, light rays are reflected from the object through the cornea, pupil, and lens. The cornea and lens focus the rays onto the retina, which converts the light into electrical signals. These signals are then carried to the brain along the optic nerve.
Reasons for Procedure
The lens of the eye is made of mostly water and protein. As we age, some of the protein may clump together and cloud the lens. This is a cataract. Over time, the cataract may become denser, making it harder to see.
Symptoms of cataracts include: cloudy, fuzzy, foggy, or filmy vision, faded colors, poor night vision, glare from lamps, headlights, or the sun, double vision, poor contrast, need for frequent changes in your eyeglass prescription. As cataracts develop, some people may notice a temporary improvement in their ability to see objects up close.
Cataracts are treated with cataract surgery, which is the replacement of the natural lens with an artificial one. There are currently no other procedures, medications, or corrective lenses for cataracts. However, in some rare cases, you can obtain slightly better vision with dilating drops prescribed by your doctor.
Before deciding on surgery, your doctor will perform an eyeglass examination to determine your best corrected vision.
Not all cataracts require surgery. In most cases cataracts develop slowly, and people are able to function for years by gradually adjusting their lifestyle before surgery becomes necessary.
In the days leading up to your procedure: Arrange for a ride to and from the hospital. If you regularly take medications, herbs, or dietary supplements, ask your doctor if and when you need to temporarily discontinue them. Do not start taking any new medications, herbs, or dietary supplements before consulting your doctor. Your ophthalmologist may ask you to see your primary care physician to make sure you are medically cleared for cataract surgery.
Before the procedure: eye drops are usually administered to dilate your pupil; antibiotic and/or anti-inflammatory drops are also sometimes given; a sedative may be given to help you relax; a local anesthetic may be injected around your eye or numbing eye drops may be placed in your eye; the area around your eye will be washed.
Most cataract surgeries last less than an hour. The most common method of cataract surgery is phacoemulsification. In this procedure, your surgeon will begin by making one or more small incisions either just inside or outside of the cornea edge.
Your surgeon will introduce an ultrasound probe connected to a tiny vacuum through these openings. He or she will use the probe to break up the lens and remove its fragments.
Then, your surgeon will insert a new lens made of a synthetic material such as silicone or acrylic. Since the incisions are so small, they will usually heal on their own without stitches.
Another method of cataract surgery is called the extracapsular technique. In this procedure, the incision at the base of the cornea is large enough to remove the cataract whole. Again, an artificial lens will replace the natural lens. Stitches are required to close this larger incision.
Risks and Benefits
Although complications are rare, they can occur. The risks of cataract surgery include, but are not limited to: a fragment of the cataract falling into the back of the eye, which may require further surgery, bleeding inside the eye, persistent eye pain, redness, and swelling, persistent inflammation of the eye, development of a film behind the new lens implant, requiring a laser procedure to remove it.
Additional complications may include: eye infection, clouding of the cornea, which may require further surgery, glaucoma, a vision-threatening condition caused by increased pressure inside the eye, decrease or loss of vision or double vision, drooping eyelid.
Benefits of cataract surgery include: likelihood of improved vision, though visual problems unrelated to the lens will persist and may occur in the future; improved vision can never be guaranteed; no risk of future cataract in that eye, although a film can develop behind the lens implant requiring a painless laser procedure.
After the Procedure
After the procedure: You will be discharged home on the same day, since cataract surgery is generally performed on an outpatient basis. A family member or friend will need to drive you home. You will be monitored for a short time in the recovery room. A patch and/or shield will usually be placed over your eye; avoid contact with your eye until instructed by your doctor. Your doctor will usually ask you to follow up the next day in his or her office.
Contact your doctor immediately if you experience any of the following symptoms: eye pain, redness, or swelling, bleeding or discharge from the eye, loss of vision or double vision, any other worrisome problems.
- Are you at risk for cataract? National Eye Institute. Available at: http://www.nei.nih.gov/health/cataract/cataract_risk.htm. Accessed August 7, 2003
- Cataracts in adults: A patient's guide. American Society for Cataract & Refractive Surgery. Available at: http://www.ascrs.org/eye/ptguide.html. Accessed August 7, 2003.
- Cataract surgery. Queensland government. Queensland health. Available at: http://www.health.qld.gov.au/informedconsent/ConsentForms/Opthalmology/cataract_surgery.pdf. Accessed February 19, 2004.
- Cataract surgery at the University of Washington. UW Medicine Department of Ophthalmology. Available at: http://depts.washington.edu/ophthweb/cataract.html. Accessed August 7, 2003.
- Facts about cataract. National Eye Institute. Available at: http://www.nei.nih.gov/health/cataract/cataract_facts.htm. Accessed August 7, 2003.
- When you need an operation: About cataract surgery in adults. American College of Surgeons. Available at: http://www.facs.org/public_info/operation/cataract.pdf. Accessed August 7, 2003.
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