Refractive Surgery Blog

Now that corneal refractive surgery is well established and has been deemed safe and effective by the FDA, more and more patients are feeling comfortable enough to consider one of the available refractive surgical options. In particular, baby boomers in their 40s, 50s and even 60s are having LASIK performed on themselves in greater numbers in an attempt to safely, simplify their lives. But, a percentage of these patients will develop cataracts over the next ten years and will need to have them removed. These patients will expect the same excellent post-operative visual result they experienced with their refractive surgery years before. The question is: How will the refractive surgery done in years past impact your cataract surgery result?

The truth of the matter is that the calculation for the intraocular lens (IOL) that is placed in the eye after removing the cataract is trickier than was originally expected. And therefore, achieving the predicted result is not routine in patients who have had LASIK or PRK or other procedures as compared to those who have not had prior corneal refractive procedures. This is because the true power of the cornea after refractive surgery is actually less than measured by conventional instruments. Unless this is understood, post-LASIK cataract patients will end up under-corrected and farsighted following their surgery.

I have been studying this problem for several years and have performed hundreds of cataract procedures on post- LASIK, PRK, and RK patients. There are a few important features to obtaining consistent results. First, it is critical that accurate measurements of the length of the eye are obtained. We use the newest version of the IOLMaster. This device measures the length of the eye by having the patient fixate on a target and then bouncing a beam of light off of the center of the retina (macula). This is different and more accurate than measuring the length of the eye with the traditional method of using ultrasound. Secondly, the calculations become more predictable if both the pre and post LASIK corneal curvatures are known. The latter can be easily measured but the former need to be obtained from old medical records. Finally, it is important that the correct formula is used in the calculation.

What you should do now is obtain your old records before they get lost or are destroyed. Keep them in a safe place or have them copied and give them to your present ophthalmologist for safe keeping in his/her records. That way you will allow yourself the best chance for accurate calculations prior to future procedures.

http://www.cherrycreekeye.com/cataracts.html

Stuart Lewis, M.D.

Labels: Cataract Surgery after LASIK