Longitudinal changes in IOP and incident glaucoma in the Barbados Eye Studies

PURPOSE: There are a few longitudinal population studies describing the progression of intraocular pressure (IOP) or the risk of developing incident open-angle glaucoma (OAG). This report examines changes in IOP and measures the incidence of IOG over a 4-year period in the population of the Barbados Eye Studies. METHODS: The Barbados Incidence Study of Eye Disease (BISED) re-examined members of the Barbados Eye Study (BES) cohort, the original sample being based on a simple random sample of the country's population aged 40 - 84 years. At both visits patients had applanation tonometry, automated Humphrey perimetry, a comprehensive opthalmological examination, colour stereo fundus photography, blood pressure and anthropometric measurements and a detailed interview. RESULTS: A total of 3427 participants or 85 percent of the eligible cohort were re-examined in BISED. The IOP analyses were based on the subset of 2640 Black participants without glaucoma (OAG, or other type) or history of IOP lowering treatment at either visit. The mean age at follow-up was 55 years and 60 percent were women. Mean IOP was 17.3 mmHg (SDñ3.0, median 17.0) at baseline and increased by 2.6 mmHg (SDñ3.6 mmHg, median 2.3)(p<0.001by paired 1 test) in 4 years. Factors positively associated with longitudinal increases in IOP include age (p=0.001) and baseline hypertension (p=0.014) or high systolic blood pressure(p=0.005), while there was an inverse association with baseline IOP. Among the 2989 Black participants without OAG at baseline,the 4-year incidence of OAG was 2.2 percent (95 percent CI: 1.7 percent, 2.8 percent). Incidence was highest among persons classified as suspect OAG at baseline (26.1 percent) followed by ocular hypertensives with IOP >21 mmHg (4.9 percent) and lowest in persons with normal / other diagnoses and with IOP ó21 mmHg (0.8 percent). However, 32 of the 67 new cases of OAG (48 percent) had IOP ó21 at baseline. CONCLUSION: Significant increases in IOP were seen at 4-year follow-up in persons without glaucoma or IOP-lowering treatment history. While high IOP increases the risk of OAG, almost half of the incident cases had IOPó21mmHg at baseline. These results highlight the importance of prognostic factors, other than IOP, in determining the development of OAG.(AU)

Cataract and mortality in an Afro-Caribbean population: the Barbados eye studies

OBJECTIVE: Age related cataract is the major cause of visual impairment globally, and is more prevalent in black than white populations. Several studies have shown associations between cataract and mortality, and this report aimed to examine whether lens opacities were associated with mortality in an Afro-Caribbean population. DESIGN AND METHODS: The Barbados Incidence Study of Eye Disease (BISED) re-examined the Barbados Eye Study (BES) cohort, which was based on a simple random sample of Barbadian-born citizens, age 40 to 84 years. Eighty-five percent of those eligible (3,427 participants) has a 4-year follow-up visit. Both visits included an interview, anthropometric measurements, and a detailed ophthalmologic examination, including lens grading with the LOCS II method. Mortality was verified from records held at the Ministry of Health. RESULTS: Cardiovascular disease was the principal cause of death (3.7 percent), followed by malignant neoplasms (1.4 percent). Cumulative 4-year mortality increased from 3.1 percent among those without cataract to 6.0 percent, 8.9 percent and 19.6 percent for cortical-only, nuclear-only and mixed cataract, respectively. An independent association was demonstrated between mixed opacities and 4-year mortality (death rate ratio: 1.6). Co-existing diabetes acted as an effect modifier, increasing mortality in those with mixed lens opacities. The presence of any nuclear cataract (death rate ratio 1.5) was also associated with an increase risk of death. CONCLUSION: This study is the first to confirm an association between cataract and mortality in a population of African descent.(AU)