Eight-Year Incidence of Open-Angle Glaucoma in the Tema Eye Survey.

PURPOSE: To determine the incidence of open-angle glaucoma (OAG) and its risk factors in the Tema Eye Survey in Ghana, West Africa. DESIGN: Longitudinal, observational population-based study. PARTICIPANTS: One thousand two hundred five of 1500 participants 40 years of age or older selected randomly from 5603 participants originally drawn from the population and who had undergone a baseline examination. METHODS: All participants underwent baseline and follow-up ophthalmologic examinations 8 years apart. Glaucoma diagnosis was determined based on the International Society for Geographical and Epidemiologic Ophthalmology criteria. MAIN OUTCOME MEASURES: Incidence and odds ratio (OR). RESULTS: The response rate was 80.3%. Of 1101 nonglaucomatous participants at baseline who had complete follow-up data, 4.6% (95% confidence interval [CI], 3.7%-5.2%) demonstrated OAG over the 8-year period, or 0.58% (95% CI, 0.4%-0.8%) per year. The 8-year incidence increased with age from 3.1% in those 40 to 49 years old to 7.0% in those 60 to 69 years old. Baseline risk factors for incident OAG were male gender (OR, 2.1; 95% CI, 1.1-4.0; P = 0.025), older age relative to those 40 to 49 years old (those 50-50 years old: OR, 2.6; 95% CI, 1.2-5.7; those 60-69 years old: OR, 4.3; 95% CI, 2.0-8.8; and for those 70 years of age and older: OR, 6.3; 95% CI, 2.6-15.4; all P < 0.001), higher intraocular pressure (IOP; OR, 1.4; 95% CI, 1.1-1.8; P < 0.001), larger vertical cup-to-disc ratio (OR, 5.8; 95% CI, 5.2-6.6; P < 0.001), and thinner central cornea (OR, 1.2; 95% CI, 1.03-1.5; P = 0.013). A separate analysis performed with central corneal thickness-based IOP correction did not change the outcome of the associative model of incident glaucoma. CONCLUSIONS: The incidence of OAG is higher in this population than reported in nonblack populations outside Africa. This is important not only in Ghana and probably other West African countries but also wherever people of the West African diaspora reside. These data enhance our understanding of the epidemiologic factors of OAG in this setting and may serve as reference for public health policy and planning.

Peripheral retinal vasculopathy in childhood glaucoma.

PURPOSE: To report wide-field fluorescein angiography findings in the peripheral retina of eyes with childhood glaucoma. METHODS: Fluorescein angiograms were examined retrospectively in 12 patients with childhood glaucoma who underwent wide-field fluorescein angiography after surgical or medical treatment of glaucoma. This series included 12 eyes of 6 patients with primary congenital glaucoma, 5 eyes of 3 patients with glaucoma associated with congenital cataract surgery, 4 eyes of 2 patients with glaucoma associated with a systemic condition, and 1 eye of 1 patient with phakomatosis pigmentovascularis Type II. RetCam fundus photography images and digital fluorescein angiography were performed under general anesthesia. RESULTS: The most common finding observed in our series was peripheral retinal nonperfusion, which affected 20 eyes (91%). Other notable features seen were circumferential branching of the retinal vessels parallel to the ora serrata (77%), venous shunts (50%), and abnormal capillary branching patterns, including capillary dilatation (41%) and tortuous capillary tangles (18%). Leakage at the junction of vascular and avascular retina was not commonly seen (13.6%). None of the eyes had evidence of retinal neovascularization or fibrovascular proliferation. CONCLUSION: Retinal vascular abnormalities and peripheral nonperfusion are novel findings in childhood glaucoma. Further studies are needed to understand the significance and possible long-term consequences of these findings.

Incidence of Glaucoma Progression and Rate of Visual Field Deterioration in a Cohort of Urban Ghanaians.

PRCIS: The annual incidence of glaucoma progression (9.7%) and rates of visual field mean deviation (MD) change in progressors (-1.02±0.06 dB/y) are high in a small cohort of urban Ghanaians. PURPOSE: To report the incidence of glaucoma progression and the rate of visual field deterioration in a small cohort of Ghanaians. METHODS: One hundred ten subjects (204 eyes) diagnosed with glaucoma at a baseline population-based screening examination were re-examined a mean of 8.3±0.8 years later. Eyes were classified as having progressed if the optic disc alone, visual field alone or both showed significant glaucomatous changes on follow-up. Visual field MD was used to calculate the rate of visual field progression. RESULTS: Progression was observed in 89 (80.9%, 9.7%/year) subjects (130 eyes). Progression occurred in 32 (31.7%, 3.8%/year) subjects by optic disc alone (46 eyes), 38 (44.7%, 5.4%/year) subjects by visual field alone (58 eyes), and 19 (25.0%, 3.0%/year) subjects by both modalities (26 eyes). The average rate of change in MD differed significantly between progressors (-1.02±1.06 dB/y) and nonprogressors (+0.089±0.49 dB/y), P =0.001. The rate of visual field worsening was greater among those who were classified as having progressed by both structure and function (-1.29±0.68 dB/y) and by function alone (-1.21±1.20 dB/y) than by structure alone (-0.55±0.76 dB/y). Progression was significantly associated with older age [odds ratio (OR), 1.42; P <0.001] and higher baseline intraocular pressure (OR, 1.18; P =0.002). Factors associated with rate of MD change were baseline older age (OR, 1.66; P =0.003), higher intraocular pressure (OR, 2.81; P =0.007), better visual field MD (OR, 1.41; P =0.004), and systemic hypertension (OR, 1.15; P =0.029). CONCLUSION: The incidence and rate of visual field progression are high in this longitudinal study of Ghanaian subjects with glaucoma. The findings may have important clinical and public health policy ramifications.

Comparison of central corneal thickness using anterior segment optical coherence tomography vs ultrasound pachymetry.

PURPOSE: To determine if there is a systematic difference in central corneal thickness (CCT) measured using anterior segment optical coherence tomography (AS-OCT) as compared with ultrasound pachymetry. DESIGN: Prospective observational study. METHODS: Consecutive subjects with clinically normal corneas underwent CCT measurement by both ultrasound and AS-OCT while participating in a population-based study in Ghana, West Africa. One eye of each subject was randomly selected for analysis. Two measurements were taken and averaged. Agreement and interobserver variability were also analyzed. RESULTS: One hundred and fifty-five subjects of African ethnicity and average age 57 years (standard deviation [SD] 12; range, 40 to 98 years) were included. Measurements by AS-OCT and US were taken a mean of 15 days (maximum, six weeks) apart. The mean (SD) [range] US CCT was 525.3 microm (33.5) [422, 653] and 499.0 microm (32.0) [428, 613] with AS-OCT. Measurements by the two modalities were strongly correlated (r(2) = 0.82; P < .001), and a significant difference was observed between mean US and AS-OCT CCT (SD) [range] of 26.3 microm (14.2) [-63, 12] (P < .001). The width of the limits of agreement was 28 microm, about 6% of the average pachymetry reading. In 50 eyes randomly remeasured with OCT by a second observer, the intraclass correlation coefficient was 0.91. There was a small but significant systematic difference between observers (mean 6.9 microm, SD 10.9 microm), or 1.4% (P < .001), increasing the difference noted above. CONCLUSION: There is a reproducible systematic difference between CCT measurements taken with ultrasound and OCT. It is important to note in clinical practice, that measurements acquired by these two modalities are not directly interchangeable.

Longitudinal Change in Central Corneal Thickness in the Tema Eye Survey.

PURPOSE: To determine the change and rate of change in central corneal thickness (CCT) and their determinants. DESIGN: Longitudinal observational population-based study. METHODS: A total of 758 normal and 58 glaucomatous subjects underwent complete eye examination, with CCT measurements at 2 separate visits. Change and rate of change in CCT were determined. Univariate and multivariate linear regression analyses were performed to determine the factors associated with change and rate of change. RESULTS: The mean follow-up duration was 8.4 ± 0.7 years. The overall change was -8.9 ± 16.7 µm in OD and -9.8 ± 16.2 µm in OS, both P < .0001. Changes in glaucomatous and normal subjects were -14.1 ± 2.2 µm vs -8.6 ± 0.6 µm in OD (P = .02) and -14.5 ± 2.2 µm vs -9.5 ± 0.6 µm in OS (P = .03), respectively. The overall rate of thinning was -1.1 µm/year (OD) and -1.2 µm/year (OS). Rates in glaucomatous and normal eyes were -1.7 ± 0.3 µm/year vs -1.0 ± 0.1 µm/year in OD (P = .02) and -1.7 ± 0.3 µm/year vs -1.1 ± 0.1 µm/year in OS (P = .03), respectively. Change and rate of change were associated with baseline CCT (ß = -0.1 to -0.09 and -0.011, respectively, all P < .001) and glaucoma (ß = -6.8 to -5.6, P ≤ .009, and -0.75 to -0.69, P ≤ .007, respectively). CONCLUSION: CCT decreased significantly over time. The change and rate of change were greater in glaucomatous than normal eyes, and were greater than described in cross-sectional studies.

Residual and Dynamic Range of Retinal Nerve Fiber Layer Thickness in Glaucoma: Comparison of Three OCT Platforms.

PURPOSE: To estimate visual field (VF) sensitivity at which retinal nerve fiber layer (RNFL) thinning reaches the measurement floor and at which RNFL stops thinning (change points), the dynamic range of RNFL thickness, and the number of steps from normal to RNFL floor among three optical coherence tomography (OCT) devices. METHODS: Glaucomatous patients (n = 58) and healthy subjects (n = 55-60) prospectively underwent VF testing and RNFL thickness measurement with Cirrus, Spectralis, and RTVue. Change points and corresponding RNFL thicknesses were estimated with simple linear regression (SLR) and Bayesian change point (BCP) analyses. The dynamic range and number of steps to RNFL floor were determined. RESULTS: The average VF change points and corresponding residual thickness at the time RNFL stopped thinning were -22.2 dB and 57.0 µm (Cirrus), -25.3 dB and 49.2 µm (Spectralis), and -24.6 dB and 64.7 µm (RTVue). The RNFL dynamic ranges derived from SLR values were wider on Spectralis (52.6 µm) than on Cirrus (35.4 µm) and RTVue (35.5 µm); the corresponding number of steps to reach the RNFL floor were 9.0 on Cirrus, 10.6 on Spectralis, and 8.3 on RTVue. CONCLUSIONS: The relative VF sensitivity at which average RNFL thickness reaches the measurement floor, the residual layer thickness, and RNFL dynamic measurement range differ among the three devices. However, the number of steps from normal to the RNFL thickness floor is comparable.

Peripheral fluorescein angiographic findings in fellow eyes of patients with branch retinal vein occlusion.

Introduction. Branch retinal vein occlusion (BRVO) is a common retinal vascular condition that results in intraocular inflammatory changes. Ultra wide field fluorescein angiography (UWFFA) is a retinal imaging device that can capture peripheral retinal findings. The purpose of this study was to look for peripheral findings in the fellow eye of patients with BRVO using UWFFA. Methods. Retrospective imaging review of patients diagnosed with BRVO that had both eyes imaged with UWFFA. Images were graded for peripheral findings in other quadrants of the same eye as well as in all quadrants of the fellow eye. Results. Of 81 patients, 14 (17%) patients had late vascular leakage in a quadrant other than the BRVO distribution. Five (6%) findings were in the same eye, 8 (10%) findings were in the fellow eye, and 1 (1%) finding was in both the same eye and the fellow eye. Of these 14 patients, 11 (80%) patients had hypertension. Conclusion. Late peripheral retinal leakage in the fellow eye of patients with BRVO was detected in this cohort of patients with UWFFA. This novel finding may represent underlying systemic inflammation, hypertension, or bilateral BRVOs.

Long-term comparison of primary trabeculectomy with 5-fluorouracil versus mitomycin C in West Africa.

PURPOSE: To compare the long-term efficacy and safety of intraoperative 5-fluorouracil (5-FU) versus mitomycin-C (MMC) used adjunctively with primary trabeculectomy in a Black West African population. DESIGN: Retrospective comparative study supplemented with cross-sectional follow-up data. METHODS: Review of 68 eyes of 68 Black West African subjects that underwent primary trabeculectomy with the use of intraoperative 5-FU or MMC between January 1, 1988 and January 1, 2002 and had at least 3 years postoperative follow-up. Postoperative outcome measures included intraocular pressure (IOP) control, number of glaucoma medications, visual acuity, and complications. RESULTS: Thirty-eight of sixty-eight eyes received 5-FU and 30 received MMC. Mean postoperative follow-up was 7.5 and 6.5 years in the 5-FU and MMC groups, respectively (P=0.17). A higher proportion of eyes in the MMC group achieved "qualified" (with or without medical therapy) success with varying IOP targets relative to the 5-FU group, but the differences were not statistically significant. "Complete" (without medical therapy) postoperative success was greater in the MMC group with a significantly higher proportion achieving an IOP <21 mm Hg (P=0.02). MMC use was also associated with a lower likelihood of receiving IOP-lowering medications postoperatively (P=0.01). Baseline demographic characteristics, preoperative and postoperative IOP, visual acuity, and complications did not differ significantly between the 2 groups. CONCLUSIONS: Intraoperative MMC use is associated with a lower likelihood of requiring postoperative medications and a greater likelihood of achieving IOP lowering without medications relative to the use of 5-FU in a Black West African population.