Cataract patients planning to undergo lens replacement surgery will have tests that examine (a) the power of the cornea and (b) the length of the eye - the primary measurements needed to formulate the synthetic lens to be implanted. The meticulous corneal examinations are also useful for patients with astigmatism and glaucoma.
- Corneal topography uses highly sophisticated technology to create a precise three-dimensional map of the cornea.
- Corneal pachymetry uses ultrasound to measure the thickness of the cornea.
- Ultrasound biometry ("A-scan") measures the length of the eye with ultrasound.
- Optical coherence biometry also measures the length of the eye but uses light instead of ultrasound.
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| Laser Cataract Surgery |
The ophthalmologist will use all this data to calculate the best intraocular lens (IOL) type and power to be implanted. For the most accurate measurements, keep soft contact lenses out of your eyes for three days before your evaluation. If you wear hard contacts or rigid gas permeable (RGP) contacts, stop wearing them three weeks before the evaluation.
Once your cataracts are diagnosed, it will be up to you to decide when they are unacceptably interfering with your work and your lifestyle.
Planning for Cataract Surgery
If you're like most people, eventually your cataracts will become more than an inconvenience. Stronger glasses or contacts, magnifying devices and better lighting, and other interim measures can do only so much to help you see better.
When you sense that the time for surgery has come, you'll want to discuss the procedure - removing the natural lens and replacing it with a man-made lens - with your ophthalmologist. Surgery to remove the cataract is the only effective treatment for cataracts, despite promotions you might have seen endorsing cataract-reducing medications, exercises, eye drops, and optical devices.
Cataract surgery produces better vision for nearly all patients - an astounding 98 percent, according to the Eye Surgery Education Council. If you have other eye conditions, such as macular degeneration or advanced glaucoma, your doctor will explain how these disorders might affect the results of cataract surgery and will make treatment recommendations for them.
Are You a Candidate for Cataract Surgery?
Almost anyone who has cataracts and who is in reasonably good health, regardless of age, can have cataract surgery. Here are a few things to keep in mind, however:
- Remember that cataract surgery corrects only cataracts and won't fix other eye problems. Ask your doctor how well you can expect to see after lens replacement if you have macular degeneration, diabetes, glaucoma, extreme nearsightedness, or very small pupils.
- Replacing the clouded lens with a clear one might well improve your eyesight, just as a clear camera lens will give you a sharper photograph than a scratched or blurry lens. But if your retina is damaged, it's like having defective film in your camera. Depending on the type of damage, cataract surgery might or might not help.
- Extremely nearsighted people present special challenges to the surgeon. "High myopes" can have excellent results from cataract surgery and lens replacement, but the process is more complicated. They are at greater risk for retinal detachment, macular disease, and inflammation than other cataract-surgery patients. It's also harder to calculate the precise "prescription" for the replacement lens and to keep the lens stable after surgery.
Extreme nearsightedness by no means disqualifies you for lens replacement, but you'd be well advised to find an ophthalmologist who is very experienced with cataract surgery on highly myopic patients.
- You'll want to postpone your surgery if you've recently had an infectious (viral or bacterial) illness or any unexplained health problems, such as chest pain.
- If you take blood-thinning medication - aspirin or warfarin (Coumadin), for example - talk with your doctor about the type of surgery you'll be having. You won't have to stop taking blood-thinning drugs if you are having the clear-corneal pbacoemulsification procedure, in which there is no bleeding.
- Don't expect the impossible. In all likelihood, you'll be delighted with the improvement in your eyesight after you've adjusted to your new lenses - as long as you don't expect to see as well as you did in your teens and twenties.