Articles about Eye Health and Disease 2001
 

Association between Cataract and Increased Mortality Rate in Blacks

(From A Hennis, PhD et al. Lens Opacities and Mortality: The Barbados Eye Study. Ophthalmology 2001;108:498-504.)

The Barbados Eye Study measured the prevalence and risk factors for major causes of visual loss among 4709 Barbadian-born citizens, aged 40 to 84 years (1988-1992). Individuals were randomly chosen for the study, which included a comprehensive eye examination, which was then repeated in four years. In this study looking at cataract vs. cause of death, 306 of 4314 black participants had died before the four year follow-up. The type of cataract that these individuals had were compared to cataract in the surviving population.

Cataracts are a clouding of the natural lens of the eye. This can lead to visual loss, symptoms of glare and halos around lights, and changes in a glasses prescription. There are different types of cataract when examined by an ophthalmologist. A nuclear sclerosis cataract is a generalized haziness throughout the lens. A cortical cataract is a sheet-like or spoke-like clouding of the front part of the lens. A posterior subcapsular cataract is a crust-like clouding across the back of the lens.

This study found that the type of cataract that an individual had at the initial examination was a risk factor for death within the following four years (before the follow-up examination):

• Those without cataract had a 3.2% mortality rate within four years.

• Those identified as having "mixed cataracts", meaning that the lens had a mixture of different types of cataract, had a 20.9% mortality rate.

• Those with the "nuclear sclerosis" type of cataract had a 8.8% mortality rate.

• Those with the "cortical" type of cataract had a 6.0% mortality rate.

• Cardiovascular disease was the principal cause of death in black participants, followed by cancer.

• The death rate risk increased with age, peaking at 60 to 69 years.

• Diabetes further increased the mortality risk, and those with diabetes and the mixed type of cataract had a 2.7 fold increased risk of death.

Overall, this study is the first to identify a relationship between type of cataract and mortality in an African-descent population.

 

Return to the Eye News Index of Articles Page