Slight increase in rate of diagnoses of glaucoma among young service members

The rate of glaucoma among service members between the ages of 20 and 24 was 2.3 per 1,000 person-years (p-yrs) in 1998, rising 43.9 percent to a rate of 4.1 per 1,000 p-yrs by 2013, according to the report published in the December issue of the Medical Surveillance Monthly Report (MSMR) from the Armed Forces Health Surveillance Center.

Although the incidence rate of glaucoma increased monotonically with age, rates among service members aged 35 years or older have decreased when viewed over time, with the largest declines occurring in those aged 40 years or older. The rate in 1998 among service members aged 45 years or older was 20.5 per 1,000 p-yrs, declining 47.8 percent by 2013 to a rate of 10.7 per 1,000 p-yrs, the report's analysis showed.

"These interesting data suggest that the services may be finding possible glaucoma cases earlier in service members' careers, so fewer of them are first diagnosed later on, when they're older,'' said Navy Captain Kevin Russell, director of AFHSC.

In addition to estimating the incidence of glaucoma, the report measured the overall burden of glaucoma by counting the number of medical encounters for each diagnosis category. It also examined the prevalence of several comorbid conditions known to be associated with increased risk for glaucoma, which were in health records as a single diagnosis, in any diagnostic position, of diabetes, hypertension, cataracts, uveitis, or eye injuries that occurred prior to the incident diagnosis of glaucoma.

The report identified the incidence of glaucoma for all active component service personnel in the Army, Navy, Air Force, Marine Corps and Coast Guard whose healthcare records contained a diagnosis during January 1, 1998, through December 31, 2013.

Glaucoma is considered a disqualifying condition for enlistment in the military. Glaucoma that is diagnosed while in service but deemed resistant to treatment or that affects the visual field will be evaluated by a medical examination board for possible separation from service.

The report identified a total of 117,075 incident cases of glaucoma during 1998-2013. This represents an overall incidence rate of 5.2 per 1,000 p-yrs. Among the findings:

•The rate of glaucoma among female service members was 17.6 percent higher than that of male service members. The rate was highest among black, non-Hispanic service members (8.8 per 1,000 p-yrs) and it was more than double the rate among white non-Hispanic service members (4.2 per 1,000 p-yrs). Rates among both Asian and Hispanic service members were also elevated in comparison with white non-Hispanic service members. These disparities were observed across the study period, with the exception of the early period between 1998 and 2000 when the incidence of glaucoma among Hispanic service members was slightly lower than that among white non-Hispanic service members. Just as in the civilian population, the incidence of glaucoma was higher among black non-Hispanic, Asian, and Hispanic service members, compared with white non-Hispanic or Native American service members.

•The incidence rate of glaucoma was highest among Air Force personnel (6.1 per 1,000 p-yrs) and lowest among Marines (3.5 per 1,000 p-yrs). Junior-grade service members had lower rates than senior ranking service members. Rates were higher among officers compared to enlisted personnel.

•When stratified by occupational category, service members working in the fields of healthcare and communications/intelligence had higher rates of glaucoma than those working in other fields. This is possibly due to increased healthcare-seeking behaviors in these groups.

•Among the 117,075 diagnosed cases, there were 460,355 medical encounters during which a glaucoma diagnosis was recorded. Even though borderline glaucoma represented 89.7 percent of the most specific/severe diagnoses, individuals with this diagnosis accounted for only 76.7 percent of total medical encounters. The 5.9 percent of service members ultimately diagnosed with open-angle glaucoma utilized 13.5 percent of total medical encounters.

•Twelve percent of all service members diagnosed with glaucoma had previously been diagnosed with hypertension. The prevalence of hypertension was highest among those with an incident diagnosis of absolute glaucoma (30.0 percent), and among those with angle-closure glaucoma.