This is one of the most frequently asked questions in our office. Usually, but not always, the answer is very simple. For most patients the answer is to have the surgery when vision becomes blurred to the point that it is troublesome. For many this is when they fail the DMV eye exam (worse than 20/40 in California).
The word “cataract” means waterfall. Its reference to the aging process of the lens of the eye dates back hundreds of years. It is related to the milky white appearance of a very mature cataract which was compared to that of a raging waterfall. Because of the availability of medical care such advanced cataracts are most often seen in the third world.
The cataract process begins early in life and first makes its impact on us in the mid forties when it becomes necessary to use reading glasses. Although the human lens at this stage is perfectly clear it has become more dense and thereby lost some of its elasticity. The eye's focusing muscle can no longer change the shape of the lens sufficiently to bring near objects into clear view. As decades pass the constant production of lens material with no place to expand causes the lens to becomes progressively more compact. These changes are universally seen with on routine biomicroscopic examination of patient over the age of fifty. The point at which these and other normal lens changes are called “cataract” is somewhat arbitrary but technically the term should be reserved for when a person's vision is adversely affected by their presence. The hallmark of a cataract is blurred vision.
Since cataracts are for the most part age related it is not uncommon for these patients to have other age related afflictions such as macular degeneration which can also affect vision. An important part of cataract assessment is to determine if there are other factors causing vision to be impaired and to judge what contribution is attributable to the presence of the cataract.
Cataracts are common and simply because they are present does not mean surgery is indicated. There is risk involved in any type surgery and cataract surgery is no exception. Fortunately the risk is low. I like to tell my patients that cataract surgery is a low risk, high stakes operation. It is unlikely there will be a complication but there are a hundred things that can and do go wrong, a few of which can result in permanent sight damage. If it is possible to correct vision to an acceptable level with glasses or contact lenses then that is generally a preferable choice. It cannot always be predicted but there should be a reasonable expectation that surgery will improve eyesight and restore function.
Generally the patient is the best judge of when to remove a cataract and there is no predetermined level of visual acuity, such as 20/50, at which the decision for surgery should be made. An airline pilot is more likely to have surgery at an earlier stage than someone with Alzheimer’s disease. Most cataract patients are aware of their functional disability and are capable of making a rational choice. Occasionally situations arise when the decision must be made for the patient or a when a medical condition exists that requires surgery to preserve the health of the eye. In these situations the doctor may not make the decision but will strongly advise surgery but in the vast majority of cases it is the patient who is, to user a word famously coined by our former president, the “Decider”.
Although modern cataract surgery is truly an everyday miracle, there is some wisdom in the adage “If it aint broke, don’t fix it.”
More about this subject in future blogs.
by Dr. John Sullivan