Blue-Yellow (B-Y) Perimetry Vs White- White (W-W) in detecting glaucomatous changes

Objectives: To determine if the Koniocellular pathway is broken down before the magnocellular pathway in glaucoma. To determine if there is any significant difference in the results for W-W perimetry vs B-Y perimetry of the same patient. The koniocellular pathway is the first to be damaged in glaucoma and the B-Y method of perimetry testing would be more beneficial to the patient where any change in the progression of their glaucoma would be detected earlier. Design and Methodology: The patients of fitting criteria were randomly selected and brought into the UWI clinic for two visual field tests. Both tests required the patient to do the same thing with the only difference being the colour of lights used. The results recorded for each patient were analysed using the software SPSS. Results: The results showed that although the blue- yellow perimetry detected more visual field defects than the white on white, the difference was not statistically significant at the 0.05 level. Conclusion: Even though SPSS analysis indicated that the results obtained were not significant it was inferred that using the alternative Blue Yellow method of perimetry can be helpful in monitoring those patients who are classed as glaucoma suspects to detect earliest glaucomatous changes.

Frequency and risk factors for pterygium in the Barbados Eye Study

OBJECTIVE: To describe the disrtibution and risk factors for pterygium in the predominantly black population of the Barbados Eye Study, which was based on a random sample for Barbadian-born citizens between the ages of 40 and 84 years. METHODS: The standardized protocol included ophtalmic and other measurements, automated perimetry, lens gradings, fundus photography, and a detailed interview. A 10 percent systematic sample of participants and those meeting specific criteria also received a comprehensive ophthalmologic evaluation. RESULTS: The Barbados Eye Study included 4709 participants, of whom 2978 were referred for an ophthalmologic evaluation and 2781 (93 percent) completed the examination. Cases of pterygium were found among 23.4 percent of 2617 black, 23.7 percent of 97 mixed (black and white), and 10.2 percent of 59 white participants examined. In addition to African ancestry, logistic regression analyses indicated a positive association between pterygium and age (odds ratio [OR], 1.01; 95 percent confidence interval [CI], 1.00-1.02), fewer years of education (OR, 1.43; 95 percent CI, 1.01-2.03), and an outdoor job location (OR, 1.87; 95 percent CI, 1.52-2.29). Having a darker skin complexion (OR, 0.66; 95 percent CI, 0.52-0.83), always using sunglasses outdoors (OR, 0.18; 95 percent CI, 0.06-0.59), and the use of prescription glasses (OR, 0.75; 95 percent CI, 0.60-0.93) were protective factors. CONCLUSIONS: Approximately one quarter of the black participants examined had pterygia, a frequency that was 2.5 to 3 times higher than among whites in the Barbados Eye Study and elsewhere. Pterygium was almost twice as frequent among persons who worked outdoors but only one fifth as likely among those who always used sun glasses outdoors. Educational interventions to modify these potential exposures may assist in preventing pterygium. (AU)

Incidence of open-angle glaucoma. The Barbados Eye studies

OBJECTIVE: To measure the 4-year risk of open-angle glaucoma (OAG) in a black population. DESIGN: Population-based cohort study with 4 years of follow up. SETTING: Simple random sample of residents of Barbados, West Indies, aged 40 years or older. PARTICIPANTS: A total of 3427 members of the cohort (85 percent of those eligible). MAIN OUTCOME MEASURE: Development of glaucoma visual field defects and optic disc damage, confirmed by automated perimetry, independent fundus photographic gradings, and standardized opthalmologic examinations. RESULTS: The 4-year risk of OAG in black participants was 2.2 percent (95 percent confidence interval, 1.7 percent-2.8 percent), based on 67 newly developed cases of OAG. Incidence rates increased from 1.2 percent at ages 40 to 49 years to 4.2 percent at ages of 70 years or more, tending to be higher in men than women (2.7 percent vs 1.9 percent). About half of the incident cases were undiagnosed previously, and the rest were receiving OAG treatment. Of the 67 new cases of OAG, 32 had intraocular pressure of 21 mm HG or less at baseline (1.2 percent incidence) and 35 had higher pressures (9 percent incidence). Risk was the highest among persons classified as having suspect OAG at baseline (26.1 percent), followed by those with ocular hypertension (4.9 percent and lowest in the remining population (0.8 percent). CONCLUSIONS: This longitudinal study provides new information on OAG risk, as well as the first incidence measurement in a black population. Although intraocular pressure increased risk, about half of the new cases had baseline pressures of 21 mm Hg or less. Results substantiate the high OAG risk in the population of African origin, especially in older adults; the relative role of intraocular pressure; and the considerable underdetecion of new disease after 4 years of follow-up. (AU)

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)

The Barbados eye study

OBJECTIVE: To describe the design of the Barbados Eye Study and report of the prevalence of open angle glaucoma (OAG) in a predominantly black study population. DESIGN: Population-bases prevalence study. SETTING AND PARTICIPATION: Residents of Barbados, West Indies, identified from a simple random sample of Barbadian-born citizens 40 through 84 years old. DATA COLLECTION: Participants had a comprehensive study visit that included automated perimetry, applanation tonometry, and fundus photography; persons with specific findings, as well as a 10 percent sample of participants, were referred for an ophthalmologic exanimation and additional tests. OUTCOME: A diagnosis of OAG required both visual field and optic disc criteria for glaucoma damage after excluding other causes. RESULTS: The 4709 participants (83.5 percent of those eligible) had demographic characteristics that were similar to the census population. Of the 4631 participants who were tested at the study site, 95 percent completed Humphrey automated perimetry and 97 percent had photographic or clinical disc gradings; 93 percent of those referred completed the ophthalmologic examination. In the adult population, the prevalence of OAG by self-reported race was 7.0 percent (302/4314) in black, 3.3 percent (6/184) in mixed race, and 0.8 percent (1/1`33) in white or other participants. In black and mixed-race participants, the prevalence reached 12 percent at age 60 years and older and was higher in men (8.3 percent) than in women (5.7 percent), with and age-adjusted male-female ratio of 1.4. In addition, over 3 percent of the participants were classified as having suspect OAG. CONCLUSIONS: To our knowledge, the Barbados Eye Study is the largest glaucoma study ever conducted in a black population and identified more people with OAG than did any previous population study. The prevalence of OAG was high, especially at older ages and in men. Among participants 50 years old or older, one in 11 had OAG, and prevalence increased to one in six at age 70 years or older. The results highlights the public health importance of OAG in the Afro-Caribbean region and have implications for other populations. (AU)