Written by Tatjana Djakovic, Staff Writer.  Age related cataracts occur 3.4 years earlier in diabetics and 2.4 years earlier in non-diabetics that are statin users.

Cataracts is a clouding of the lens in the eye that affects vision normally afflicting the elderly, but diabetes has been identified as a major risk factor for age related cataracts (1,2). Worldwide, there are more than 285 million people affected by diabetes and it is expected to increase to 439 million by year 2030 (2) and a corresponding increase in age-related cataracts is expected.

A class of cholesterol lowering pharmaceuticals called statins is normally prescribed for diabetes patients. There has been little research done on the use of statins in patients with diabetes and the combined impact on cataracts. (4) A new study has investigated the impact of statins on age-related cataracts in diabetes patients. The study consisted of 6,397 patients aged 1 to 93 years old, of which 56% were diabetic patients and 16% were non-diabetic patients taking statins. The data was collected using a computer database developed from a review of all of the patients’ doctor visits from January 2007 to January 2008 at the University of Waterloo, School of Optometry and Vision Science. Factors such as gender, blood pressure, smoking status that might have an impact on the results were statistically controlled in order to solely observe the association between diabetes, statin use and prevalence of cataracts. (5)

The results indicated there were increased odds of having age-related cataracts in patients that have diabetes compared with patients with no diabetes. In addition for those taking the cholesterol lowering drug, there was 50% chance of developing cataracts at the age of 51.7 years for diabetics and 54.9 years for non-diabetics. While the patients that are not using statins, the onset of cataracts occurred at a later age of 55.1 years for diabetics and 57.3 years for non-diabetics. The results indicate earlier onset and higher prevalence of cataracts in patients afflicted with diabetes and taking statins.  (5)

The medical explanation for higher chance of development of cataracts in patients taking cholesterol lowering medications suggests that the lens membrane of the eye requires high cholesterol for proper cellular function and lens transparency. Previous studies have shown in both humans and animals that there is an increased risk of cataract formation in those afflicted with hereditary cholesterol deficiency. (6) The use of statins in diabetes patients has increased the probability of early onset of cataracts and therefore it is extremely important to avoid these risk factors.

Source: Machan, Carolyn M., Patricia K. Hrynchak, and Elizabeth L. Irving. “Age-related cataract is associated with type 2 diabetes and statin use.” Optometry & Vision Science 89.8 (2012): 1165-1171.

© 2012 American Academy of Optometry

Posted October 4, 2012.

References:

  1. Papoz L, et al. Risk factors for cortical, nuclear, and posterior subcapsular cataracts: the POLA study.  Am J Epidemiol 2000:151:497-504.
  2. National Eye Institute: Facts about Cataracts posted on the National Eye Institute website.
  3. Pollreisz A, et al. Diabetic Cataract-Pathogenesis, Epidemiology and Treatment.  Journal of Ophtalmogy 2010: doi:10.1155/2010/608751.
  4. Hermans MP et al., Statin therapy and cataract in type 2 diabetes.  Diabetes Metab 2010;37:139-43.
  5. Irving EL.  Age-Related Cataract is Associated with Type 2 Diabetes and Statin Use.  Optometry and Vision Science. 2012: 89(8): 1165-1171.
  6. Cenedella RJ.  Cholesterol and Cataracts. Surv Ophthalmol 1996; 40:320-37.