Cataract Surgery and 5-year Mortality Rates In a Veterans Population

 

Soo Yeon Kim, MD and Brian R. Sullivan, MD

University of Texas Southwestern Medical Center at Dallas

Veterans Affairs North Texas Healthcare System

Supported in part by an unrestricted research grant from Research to Prevent Blindness, Inc.New York, New York, U.S.A.

IntroductionCataract is a common cause of visual disability among the elderly,

and the incidence of cataract increases with age.

Biochemical and structural changes that take place within the human crystalline lens have been likened to degenerative processes that occur in other parts of the body as a consequence of aging. Because senile cataracts may be a marker of generalized tissue aging, multiple studies have examined mortality rates related to cataract extraction.

Several previous reports have indicated that higher or equal rates of mortality are associated with cataract surgery, but a recent study provided evidence that cataract surgery may actually associated with increased survival, perhaps due to advancements in quality outcomes and changing demographics of patients undergoing cataract surgery.

To date, no published report has examined this relationship among veterans.

Purpose and MethodsPurpose: Determination of 5 year mortality

data among a large population of veterans who underwent cataract surgery and to compare the findings to general populations in the state of Texas and within the VA Health Care System.

Methods: Retrospective review of cataract surgery cases performed in a consecutive five year period at the Dallas VA Medical Center.

Results1293 eyes of 1065 patients underwent cataract

surgery in the study period from 1999-2003.

24.4% (260 of 1065 subjects, accounting for 305 cataract procedures) had expired within five years of surgery.

Mean time from date of surgery to date of death was 29.6 months, and average age at death 74.2 years.

Results

Average age at the time of surgery was 67.8 years. Of subjects that expired within 5 years, the average age at surgery was 71.3 years. By contrast, the average age at the time of surgery for survivors at 5 years was 66.7 years. This difference in ages at the time of surgery between survivors and non-survivors was statistically significant with a p-value of <0.0001.

ResultsThe overall death rate among subjects

undergoing cataract extraction was 24.4%. Using data from the National Center for Health Statistics, the mortality rate for age-matched population (ages 45 and over) in the state of Texas from 1999-2005 was 26.8% (see table 3). Mortality rates in cataract surgery patients per year were not statistically significant in comparison to Texas mortality rates (p-value 0.09).

Results

ResultsHowever, when subjects were stratified into 10-year

age groups, the differences in mortality rates per age group were statistically significant in all age groups except for ages 45-54 (see tables 3 and 4).

There was a trend toward earlier deaths in the study population when compared to the Texas population. The greatest number of veteran deaths was between the ages of 75-84; however, in the Texas population, the number of deaths was greatest for the population 85 years and over (p-value < 0.0001).

Results

Results

The calculated death rate is not statistically different from mortality statistics recorded for a population of United States veterans.

Of all deaths in the study population, 41.2% involved phacoemulsification and 58.9% were ECCE, a difference which is statistically significant (p-value 0.0224).

Conclusion

ECCE was associated with a higher mortality rate when compared to phacoemulsification.

Although a moderate trend of increased mortality rates was found when compared to general public mortality data, cataract surgery does not appear to be a significant predictor of mortality within the patient population of the VA Health Care System.

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