Educational Materials: CATARACT SURGERY
WHAT IS A CATARACT AND HOW DOES IT AFFECT SIGHT?
A cataract is a clouding of the normally clear and transparent lens of the eye which lies behind the pupil. When the lens becomes cloudy from age, injury or a birth defect, less focused light reaches the interior of the eye and vision gradually fails. Symptoms of cataracts range from a barely noticeable loss of vision to virtual blindness. The first symptom may be difficulty in performing routine tasks. Fuzzy or blurred vision, frequent changes in glasses, double vision in one eye, problems reading, decreased color perception and poor night vision are common symptoms. Night driving may be a particular problem. Vision may fluctuate from normal to almost complete blindness under bright light or glare conditions.
HOW IS VISUAL LOSS FROM CATARACTS EVALUATED?
A medical eye examination, including a check for glasses (refraction), is necessary. In early stages of cataract, a change in glasses may be all that is necessary to improve vision. During the examination, your ophthalmologist will determine if there are other causes of vision loss. The usual test for visual acuity, the letter eye chart, may not reflect the true extent of your visual loss. Other tests which measure glare sensitivity, contrast sensitivity, night vision, color vision and side or central vision may be useful. Some of these tests may help predict the degree of visual recovery after cataract surgery.
HOW FAST DO CATARACTS PROGRESS?
Most cataracts associated with aging progress slowly. Some patients do not notice the extent of their visual loss because of the slow onset. Other cataracts, especially in younger people and diabetic patients, progress rapidly over a few months and vision deteriorates quickly. It is not possible to predict exactly how fast cataracts will progress in any given patient.
WHEN SHOULD YOUR CATARACT SURGERY BE DONE?
Surgery is the only effective way to remove a cataract. When cataracts cause enough loss of sight to interfere with your work or lifestyle it is time to remove them. You and your ophthalmologist should decide together when surgery is desirable. The ability to safely operate a motor vehicle is a consideration for some people. Surgery is not necessary just because a cataract is present. Symptoms may be mild and well tolerated. On the other hand, there is seldom a need to delay surgery when vision loss from a cataract interferes with your daily activities. It is a misconception that cataracts need to be “ripe” before removing them. Surgery can be performed whenever visual needs require it.
WHAT CAN YOU EXPECT FROM CATARACT SURGERY?
Cataract surgery is a highly successful procedure. Useful vision is restored in over 90% of the cases. However, it is important to understand that complications can occur. As with any surgery, a good result cannot be guaranteed. There may be other reasons for visual loss in addition to the cataract, particularly problems involving the retina or optic nerve. If these problems are present, return of vision after cataract removal may not be perfect. If these conditions are severe, removal of the cataract may not result in any visual improvement. An examination by an ophthalmologist can help predict whether visual improvement is likely.
WHAT ABOUT A SECOND OPINION?
With cataract surgery the best second opinion is often your own, since you are in the best position to determine how much your cataract interferes with your daily activities. However, if a second medical opinion is required or you feel that recommended cataract surgery may not be necessary, a second opinion may be obtained from another ophthalmologist. Since the timing of cataract surgery is a personal matter, there is no right or wrong opinion, and ophthalmologists may have differing recommendations.
IS LOSS OF VISION THE ONLY CRITERION FOR CATARACT REMOVAL?
There are two circumstances in which removal of a cataract should be considered even though improvement in vision may not be expected. A cataract may be so advanced that diagnosis or treatment of other eye disease cannot be performed properly. In this situation it may be best to remove the cataract so the interior of the eye can be examined. It is also possible for a cataract to become so advanced that the cataract itself causes other eye disease, particularly inflammation or glaucoma. These rare situations are the only ones in which cataract removal may be considered an emergency.
Remember, an ophthalmologist is the only doctor who provides total eye care: medical, surgical and optical. It’s your sight. Your eyes deserve the best care available.