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pondelok 15. augusta 2011

A Patient’s Guide to Cataract Surgery Part 4: If you chose to wait


So what to do if you or a loved one has been diagnosed with cataracts that are in need of removal?  Firstly, know that cataract removal is very rarely an emergency.  If you decide that you would rather wait, in most cases there is no damage caused by leaving the cataract inside your eye for months to years longer.  An example: this past spring I spoke with a patient about removing his cataracts, and he told me that he had a lot of gardening to do over the next few months and would rather wait until winter.  As long as the cataract is not causing any urgent conditions like glaucoma or an acute inflammatory event,  any patient is free to wait until they are 100% ready for surgery.

Not everyone is ready for surgery when their cataracts are ready to be removed and that is ok!   Many patients schedule surgeries around their hobbies, families, or vacations.  

Some things to know if you choose to wait:

Your cataracts will NOT get better.  I'm sure most of you already figured that, but cataracts do not regress with time because they are not a disease.  They may stabilize or they may get worse; it is hard to predict their exact rate of progression.   One very important point to remember: if your cataracts are bad enough to need surgical removal, glasses will NOT improve your vision.  This can be such a frustrating truth to patients. I feel very sympathetic to anyone that comes to me with a handful of glasses that they have purchased over the last few years trying to see clearly, but they just won’t work!  Glasses might be able to make a small improvement, but when a patient is referred for cataract surgery it is because their “best corrected visual acuity” meets removal criterion (typically worse than 20/40).  The “best corrected” is key; it means that even with the absolute perfect pair of glasses your vision is still worse than this 20/40 guideline.  For comparison, 20/20 is technically "perfect" vision; 20/40 is twice as bad as you are used to seeing if you had perfect vision before cataracts. Another point about 20/40 is that it is usually the cut-off for getting your driver’s license.  If the vision in both of your eyes is worse than this with glasses, you aren’t legally eligible to drive without special permissions granted by the DMV in your state!

If the cataract is getting denser and thicker and cloudier, this means that your vision will continue to deteriorate.  Typically the deterioration in vision is very slow and gradual so waiting months to a year will not make much of a difference to most people. There are some exceptions to this rule, however:
                -- If you have a posterior subcapsular cataract (commonly found in people with diabetes or cataracts secondary to steroid use), these cataracts progress much more quickly.  I have seen a patient with 20/50 vision reduced to 20/200 in a matter of 6 months, simply because his posterior subcapsular cataracts were right in the center of his vision.  He could no longer read and was having trouble recognizing faces in just 6 months’ time!
Posterior Subcapsular Cataract with classic "swiss cheese" appearance is known for fast progression and poor central vision, especially noted with reading.

                --If you have a child diagnosed with cataracts, they do need to be removed as soon as your ophthalmologist deems it appropriate.  As stated in my previous post, children are developing their visual pathways even through age 8.  If the cataract is not removed in a timely fashion, the pathway will fail to develop normally and their vision will be permanently decreased. 
                --There is one other “false” exception to the concept that your vision will not get better with cataracts.  Some people early in their cataract progression experience a phenomenon called “second sight.”  These patients typically have nuclear cataracts (one of the most common types due to aging changes).  Nuclear cataracts are known to cause myopia, or decreased distance vision.  Because of the way the visual system is set up, an eye that can’t focus in the distance focuses more clearly up close.  This is why myopia is also called near-sightedness (we will discuss this more thoroughly in future posts).  Second sight occurs when patients experiencing normal, age-related decreased near vision develop cataracts causing myopic shift (or shift to clearer near vision).  They think they are seeing better all of a sudden when reading!  The problem is, the cataract will continue to worsen and the cloudiness and blur it creates will eventually wipe out this “second sight” improvement.   This is a difficult concept to grasp, and I am still learning how best to explain to my patient’s that they think they are seeing better when reading because their cataracts are getting worse!

One last issue if you choose to wait: it is possible that your surgery will be more difficult if you delay removal for years.  Remember, the cataract forms in the structure called the lens.  The lens is one of very few body parts that actually grows every year as long as you live.  That means that once cataracts begin to develop, they keep getting thicker and harder and denser.  They can get so hard that the surgical instruments actually have a hard time removing the cataract!  This leads to more inflammation and a higher risk of surgical complications.

To wrap our cataract discussion up, I like to tell me patients that their eyes are theirs, and all I am doing is making a recommendation.  It will always be their decision if the timing is right for surgery.  If you want to wait, and don’t have any risk factors that makes this a danger to your ocular health, I will be more than happy to assist you with whatever you decide.

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