13 posts categorized "In the Journals"

February 22, 2010

Statins may Lower Incidence of Cataracts


There may be another reason to take that Lipitor besides lowering your cholesterol!  In last month's Annals of Epidemiology there was article titled: Persistence with Statins and Incident Cataract: A Population-Based Historical Cohort Study

180,291 new statin users in Israel were followed between 1998 and 2007 for incident cataract or cataract extraction. During the study period, 27,301 cataracts were diagnosed and 6,976 cataract extractions were performed among the participants.  The results showed that:

Persistence with statins was associated significantly (P < 0.001) with a reduced risk of cataract in men and women aged 45 to 74. Men aged 45–54 with a high (>80%) proportion of follow-up days covered with statins had an adjusted hazard ratio of 0.62 (95% confidence interval: 0.54–0.72), compared with patients with low persistence with statins. In elderly patients, no relationship or a positive relationship was observed.

Men who took what are commonly referred to as statin drugs had a 40% lower risk of developing cataracts and women had an 18% lower risk.

The study concluded:

Persistent statin use was significantly protective for the incidence of cataract in men and women under 75 years of age.

February 09, 2010

Young Patients with Cataracts do Better with Surgery

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This month's American Journal of Ophthalmology has an interesting article titled: Ten-Year Longitudinal Visual Function and Nd: YAG Laser Capsulotomy Rates in Patients Less Than 65 Years at Cataract Surgery.  The authors followed 102 pf 116 patients who underwent cataract surgery before the age of 65 and evaluated their 10 year results.  Here is what they found:

  • 37% of the patients under 65 at surgery had YAG capsulotomies in comparison to 20% of the older patients.  A YAG capsulotomy is used to treat an opacification of a membrane left in the eye at the time of cataract surgery (PCO) to improve vision.
  • Visual acuity diminished by more than 0.1 logarithm of the minimal angle of resolution (logMAR) units of the operated eye in 18% of the younger patients and 37% of the older patients.
  • A reduction in VF-14 score of 10 points or more was found in 9% of the younger and 28% of the older cataract surgery patients.
What this study shows is that younger cataract patients retain their improved vision more than their older counterparts.  This is good to know, as I am definitely seeing and treating more patients than ever under the age of 65.  When these patients opt for their premium lenses to help eliminate their need for glasses, I can reassure them that the vision will be lasting!

February 04, 2010

Had LASIK, Have Cataracts...Now what??


I have been performing LASIK since its inception back in 1996.  Hard to believe its been 14 years.  What I am now seeing on an ever increasing basis is patients who have had LASIK in the past complaining of a deterioration in their vision.  Many of these patients come in assuming that their LASIK is "wearing off" and that they are in need of a "fine tuning."  What is actually going on is that they have developed visually significant cataracts.

A cataract is an aging change that causes a clouding of the eye's cryastaline lens. Once visually significant, the treatment of choice is cataract extraction with the implantation of an intraocular lens (IOL).  Cataract surgery in patients who have previously had LASIK poses several unique issues.

The calculations to determine the correct IOL power are not as accurate in eyes that have undergone LASIK.  To improve the accuracy of these calculations it is helpful to have records from before the LASIK surgery including:

  • Pre operative refraction
  • Pre operative corneal curveature
  • Stable post operative refraction before the start of cataracts

Many new techniques are being investigated to improve on IOL calculations.  Just last month an article appeared in Journal of Refractive Surgery titled:  Calculation of Intraocular Lens Power Using Orbscan II Quantitative Area Topography After Corneal Refractive Surgery.  It concluded that "In eyes with previous corneal refractive surgery, IOL power calculation can be performed with reasonable accuracy using the Orbscan II central 2-mm total-mean power."

Even with all these new techniques, post LASIK patients are prone to encounter a "refractive surprise" following cataract surgery.  A refractive surprise occurs when a patient's final Rx following cataract surgery is off the mark.  Refractive surprise can be treated in several ways, depending on the amount of the surprise:

  • Mild surprises can be treated with glasses, contact lenses, or possibly with a LASIK touch up.
  • Large surprises can be treated with either an IOL exchange or the implantation of a piggy back IOL.

No matter how carefully caculations are made before cataract surgery, refractive surprises will happen.  In my opinion, patients who develop cataracts following LASIK, should seek the care of a surgeon with vast experience in both refractive and cataract surgery.  The trick here is to both minimize the amount of the surprise and to be able to efficiently treat the surprise when it is encountered.

One benefit many of my LASIK-cataract patients have is the ability to implant a multifocal IOL such as the ReSTOR.  Following the implantation of this lens, these patients are now able to see both near and far again without glasses!