A global perspective on the influence of environmental exposures on the nervous system.

Economic transitions in the era of globalization warrant a fresh look at the neurological risks associated with environmental change. These are driven by industrial expansion, transfer and mobility of goods, climate change and population growth. In these contexts, risk of infectious and non-infectious diseases are shared across geographical boundaries. In low- and middle-income countries, the risk of environmentally mediated brain disease is augmented several fold by lack of infrastructure, poor health and safety regulations, and limited measures for environmental protection. Neurological disorders may occur as a result of direct exposure to chemical and/or non-chemical stressors, including but not limited to, ultrafine particulate matters. Individual susceptibilities to exposure-related diseases are modified by genetic, epigenetic and metagenomic factors. The existence of several uniquely exposed populations, including those in the areas surrounding the Niger Delta or north western Amazon oil operations; those working in poorly regulated environments, such as artisanal mining industries; or those, mostly in sub-Saharan Africa, relying on cassava as a staple food, offers invaluable opportunities to advance the current understanding of brain responses to environmental challenges. Increased awareness of the brain disorders that are prevalent in low- and middle-income countries and investments in capacity for further environmental health-related research are positive steps towards improving human health.

Profile of central corneal thickness and corneal endothelial cell morpho-density of in healthy Congolese eyes.

PURPOSE: To determine the pachymetric and corneal endothelial cell morphometric features and their relationship to ocular and systemic factors in healthy Congolese subjects. METHODS: Non-contact specular microscopy was used in 278 healthy eyes (278 subjects) to measure central corneal thickness (CCT), corneal endothelial cell density (CECD) along with cell size, coefficient of variation (CV) in cell size, and hexagonality (HEX). The lower and upper reference limits and average values for each parameter were determined. Correlation and association of average values with anthropo-demographic and clinical variables were assessed. RESULTS: The mean age was 38.9 ± 17.2 years (10.9-80.7 years). Average values were 504.2 ± 30.7 µm (CCT), 2907.1 ± 290.9 cells/mm2 (CECD), 348.5 ± 38.4 µm2 (cell size), 32.9 ± 3.6% (CV), and 51.8 ± 7.2% (HEX). CCT was 504.9 ± 33.6 µm in men and 503.6 ± 28.3 µm in women (p = .73); values for CECD were 2917.1 ± 253.5 cells/mm2 and 2899.2 ± 317.8 cells/mm2 (p = 0.61), respectively. Lower and upper reference limits were 449.6 µm and 566.0 µm for CCT, and 2165.3 cells/mm2 and 3414.4 cells/mm2 for CECD, respectively. CCT correlated with body mass index (BMI), (r = - 0.12, P = 0.04). CECD decreased with age (r = - 0.49, P < 0.001), BMI (r = - 0.20, P = 0.001), intraocular pressure (r = - 0.13, P = 0.029) and ocular perfusion pressure (r = - 0.28, P = 0.028). CECD decayed by 8.3 cells/mm2 or 0.30% per year of age and CCT decreased by 0.72 µm per kg/m2. CONCLUSIONS: Mean central cornea was thinner, CECD higher, and references limits lower than reported in other African populations. The CCT and CECD normative values reported herein will be useful for both clinical and research purposes in this population.

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.

New developments in optical coherence tomography imaging for glaucoma.

PURPOSE OF REVIEW: Since its introduction in ophthalmology, optical coherence tomography (OCT) has undergone significant advances in imaging protocols, algorithms, and addition of new parameters which have maximized its potential for diagnosing, evaluating the response to treatment, and assessing the progression of various ocular diseases, including glaucoma. This review provides an update on recent developments in OCT with respect to the management of glaucoma. RECENT FINDINGS: Most recent notable developments include the introduction of the minimum distance band, which is a three-dimensional optic nerve head parameter, and Swept-Source OCT with its single wide-field scanning capability. The introduction of OCT angiography provides additional structural and functional measures for glaucoma management. Adaptive optics helps visualize individual RNFL bundles and measure their widths. SUMMARY: Continued improvements in OCT technology is both enhancing our understanding of glaucoma and improving our ability to manage the disease.

Optical coherence tomography platforms and parameters for glaucoma diagnosis and progression.

PURPOSE OF REVIEW: Optical coherence tomography (OCT) aids in the diagnosis and long-term monitoring of various ocular diseases, including glaucoma. Initially, the retinal nerve fiber layer was the only OCT structural parameter used in glaucoma. Subsequent research has resulted in more retinal and optic nerve head parameters. In addition, OCT is being investigated for its ability to assess ocular hemodynamics. This review summarizes these spectral domain-optical coherence tomography (SDOCT) parameters in the context of glaucoma. RECENT FINDINGS: Several new SDOCT retinal nerve fiber layer, optic nerve head, and macular parameters with good glaucoma diagnostic ability have been added to existing ones recently. The combination of SDOCT and Doppler or angiography has also resulted in hemodynamic parameters that may prove to be useful in the functional assessment in glaucoma. SUMMARY: OCT technology is advancing not only as a tool for structural assessment, but also as a multimodality tool to assess both structure and function to enhance our understanding of glaucoma, and ultimately clinical decisions.

Longitudinal changes in peripapillary atrophy in the ocular hypertension treatment study: a case-control assessment.

PURPOSE: To explore the association between peripapillary atrophy (PPA) area and conversion from ocular hypertension (OHT) to glaucoma. DESIGN: Prospective, longitudinal cohort study of cases and controls. PARTICIPANTS: We included 279 age-matched and follow-up time-matched eyes with OHT that converted to glaucoma and 279 eyes with OHT that did not convert to glaucoma. METHODS: Initial and last acceptable optic disc photos were analyzed. Disc, α-zone, and ß-zone PPA were traced independently by 2 trained readers and their areas were measured with Photoshop. The α-zone and ß-zone areas were expressed as a percentage of optic disc area. MAIN OUTCOME MEASURES: α-Zone and ß-zone PPA size over time. RESULTS: Intraclass correlation coefficients (ICCs) demonstrated that readers had good agreement on disc area (ICC = 0.97) and ß-zone (ICC = 0.82), but not α-zone (ICC = 0.48). The ß-zone, as a percentage of disc area, increased in size (P < 0.001) in both eyes with incident primary open-angle glaucoma (mean, 10.6%; standard deviation, 22.6%) and matched controls (mean, 10.1%; standard deviation, 33.7) over follow-up (mean, 12.3 years). The increase in size did not differ between cases and controls (P = 0.82). Enlargement of the ß-zone was not correlated with follow-up time (P = 0.39). CONCLUSIONS: The results did not show a difference in size of the ß-zone at baseline between eyes that proceed to develop glaucoma and those that do not. Moreover, the ß-zone enlarges equally in case and control eyes during follow-up.

Diagnostic performance of optical coherence tomography ganglion cell--inner plexiform layer thickness measurements in early glaucoma.

PURPOSE: To evaluate the glaucoma diagnostic performance of ganglion cell inner-plexiform layer (GCIPL) parameters used individually and in combination with retinal nerve fiber layer (RNFL) or optic nerve head (ONH) parameters measured with Cirrus HD-OCT (Carl Zeiss Meditec, Inc, Dublin, CA). DESIGN: Prospective cross-sectional study. PARTICIPANTS: Fifty patients with early perimetric glaucoma and 49 age-matched healthy subjects. METHODS: Three peripapillary RNFL and 3 macular GCIPL scans were obtained in 1 eye of each participant. A patient was considered glaucomatous if at least 2 of the 3 RNFL or GCIPL scans had the average or at least 1 sector measurement flagged at 1% to 5% or less than 1%. The diagnostic performance was determined for each GCIPL, RNFL, and ONH parameter as well as for binary or-logic and and-logic combinations of GCIPL with RNFL or ONH parameters. MAIN OUTCOME MEASURES: Sensitivity, specificity, positive likelihood ratio (PLR), and negative likelihood ratio (NLR). RESULTS: Among GCIPL parameters, the minimum had the best diagnostic performance (sensitivity, 82.0%; specificity, 87.8%; PLR, 6.69; and NLR, 0.21). Inferior quadrant was the best RNFL parameter (sensitivity, 74%; specificity, 95.9%; PLR, 18.13; and NLR, 0.27), as was rim area (sensitivity, 68%; specificity, 98%; PLR, 33.3; and NLR, 0.33) among ONH parameters. The or-logic combination of minimum GCIPL and average RNFL provided the overall best diagnostic performance (sensitivity, 94%; specificity, 85.7%; PRL, 6.58; and NLR, 0.07) as compared with the best RNFL, best ONH, and best and-logic combination (minimum GCIPL and inferior quadrant RNFL; sensitivity, 64%; specificity, 100%; PLR, infinity; and NPR, 0.36). CONCLUSIONS: The binary or-logic combination of minimum GCIPL and average RNFL or rim area provides better diagnostic performances than those of and-logic combinations or best single GCIPL, RNFL, or ONH parameters. This finding may be clinically valuable for the diagnosis of early glaucoma.

Normative values and predictors of retinal oxygen saturation.

PURPOSE: To determine normal retinal oxygen saturation (SO2) values measured with retinal oximetry in a multiethnic group of healthy subjects and to evaluate the association of retinal SO2 with demographic and clinical parameters. METHODS: Retinal oximetry was performed in both eyes of 61 normal healthy subjects. Global and quadrant venous (SvO2) and arterial oxygen saturation (SaO2), arteriovenous difference in SO2, and venular and arteriolar width were measured. The association of SO2 parameters with age, gender, ethnicity, refraction, iris color, history of controlled systemic hypertension, and smoking was analyzed. RESULTS: Average SvO2 and SaO2 were 55.3 ± 7.1% and 90.4 ± 4.3%, respectively. All average measurements were comparable in both eyes, both genders, and among ethnic groups. Inferonasal quadrant SaO2 was higher in Asians. Age was associated with decreased SvO2 (ß = -0.19; P = 0.001) and SaO2 (ß = -0.11; P = 0.003). History of controlled systemic hypertension was associated with an increase in arteriovenous difference in SO2 (ß = 3.99; P = 0.013). CONCLUSION: This is the first description of retinal SO2 in healthy, multiethnic subjects. Aging decreases SvO2 and SaO2 and should be accounted for when interpreting retinal oximetry measurements. Other demographic and clinical parameters studied did not seem to significantly influence retinal SO2 measurements.

Glaucoma Severity Stage at First Visit at a University Eye Clinic in Congo.

PRCIS: Initial presentation of glaucoma at a major eye clinic mostly features advanced disease with a high proportion of blindness. This is likely a microcosm of a nationwide issue requiring concerted strategies to detect glaucoma early. PURPOSE: To characterize the severity stage of new glaucoma patients and identify the predictors of late presentation in Congolese attending a university eye clinic. METHODS: New glaucoma patients (n=118) were labelled as early or late presenters based visual field sensitivity in the worse eye. Predictors of late presentation were determined through logistic regression analytical models. RESULTS: Mean age was 58.9±15.7 years, 51.7% were males. Overall, the worse eye had advanced whereas the better eye had moderate glaucoma, with an asymmetry of -7.4 dB (P<0.001). Blindness was present in 30.5% of worse and 5.1% of better eyes. Seventy-two patients (61.0%) were late presenters. Visual acuity was lower (P<0.001), intraocular pressure (IOP) higher (P=0.02), cup-to-disc ratio larger (P=0.011), and retinal nerve fiber layer thinner (P=0.001) in late presenters' worse than better eye. The worse and better eyes of late presenters had advanced glaucoma, with a -9.6 dB interocular asymmetry (P<0.001); 40.3% and 8.3% were blind, respectively. In early presenters, the worse and better eye had moderate and early disease, respectively; the asymmetry was -3.2 dB (P<0.001), and 15.2% were blind. Overall, 58.5% and 65.3% presented with advanced disease in the worse eye based on visual field and cup-to-disc ratio criteria of the Canadian Ophthalmological Society staging scale, respectively. CONCLUSIONS: Most new glaucoma patients had bilateral advanced but asymmetric disease. These findings call for the establishment of community-based measures for early detection of glaucoma and a referral network system connecting community healthcare to tertiary eye clinics.

Childhood vision impairment and blindness in West Africa: public health measures and implications for systemic health.

Childhood blindness is an issue of global health impact, affecting approximately 2 million children worldwide. Vision 2020 and the United Nations Sustainable Development Goals previously identified childhood blindness as a key issue in the twentieth century, and while public health measures are underway, the precise etiologies and management require ongoing investigation and care, particularly within resource-limited settings such as sub-Saharan Africa. We systematically reviewed the literature on childhood blindness in West Africa to identify the anatomic classification and etiologies, particularly those causes of childhood blindness with systemic health implications. Treatable causes included cataract, refractive error, and corneal disease. Systemic etiologies identified included measles, rubella, vitamin A deficiency, and Ebola virus disease. While prior public health measures including vitamin A supplementation and vaccination programs have been deployed in most countries with reported data, multiple studies reported preventable or reversible etiologies of blindness and vision impairment. Ongoing research is necessary to standardize reporting for anatomies and/or etiologies of childhood blindness to determine the necessity of further development and implementation of public health measures that would ameliorate childhood blindness and vision impairment.

Effect of pupil dilation on macular choroidal thickness measured with spectral domain optical coherence tomography in normal and glaucomatous eyes.

To compare choroidal thickness before and after pupil dilation. Macular subfoveal, nasal, temporal and average choroidal thicknesses were measured in one eye of 17 healthy individuals and 40 glaucoma patients using enhanced depth imaging optical coherence tomography before and after pupil dilation. Comparisons were made between pre- and post-dilation measurements, and between normal and glaucomatous eyes. No statistically significant differences were found between pre- and post-dilation choroidal thickness measurements both in normal (p = 0.361 for subfoveal, 0.760 for nasal, 0.941 for temporal, 0.881 for average) and glaucomatous eyes (p = 0.687 for subfoveal, 0.340 for nasal, 0.913 for temporal, and 0.642 for average). After adjusting for age, the comparison between normal and glaucomatous eyes showed no significant differences in measurements both before (p = 0.701-0.907) and after pupil dilation (p = 0.757-0.988). Similar results were obtained for measurements unadjusted for age. Measurements obtained under the two conditions correlated well in normal (r = 0.92-0.97, p < 0.001) and in glaucomatous eyes (r = 0.84-0.98, p < 0.001). Bland-Altman analyses showed good agreements between them in both groups of eyes, with mean difference ranges of 0.43-2.86 and 0.39-3.08 µm between pre- and post-dilation measurements in normal and glaucomatous eyes, respectively. Subfoveal and average choroidal thickness decreased significantly by 2 µm/year. Each millimeter increase in axial length decreased subfoveal choroidal thickness by 16.5 µm and average thickness by 14.1 µm. Macular choroidal thicknesses measured before and after pupil dilation are comparable and may be used interchangeably without significant discrepancies both in normal and glaucomatous eyes.

Agreement of Diagnostic Classification Between Structural Parameters in Pre-Perimetric and Early Perimetric Glaucoma.

PRCIS: In both pre-perimetric and early perimetric glaucoma, the diagnostic agreements between optic disk, retinal nerve fiber layer, and ganglion cell-inner plexiform layer parameters based on Cirrus HD-OCT normative database classification were mostly fair, suggesting that abnormal classification in 1 anatomic area may suffice for the diagnosis of glaucoma in early stages. PURPOSE: To evaluate the agreement of normative database diagnostic classification between optic disk, retinal nerve fiber layer (RNFL), and ganglion cell-inner plexiform layer (GCIPL) in patients with early glaucoma. METHODS: Retrospective cross-sectional study involving 66 eyes (66 patients) with pre-perimetric and 97 eyes (97 patients) with early perimetric glaucoma. Normative database diagnostic classifications were retrieved from Cirrus HD-OCT scans of 1 eye per participant. An eye was considered abnormal if any of the optic disk, RNFL, or GCIPL was abnormal (yellow or red color-coded classification). For combined parameters, the eye had to be flagged as abnormal by both classifications, regardless of the parameters that were abnormal (global or sectorial). The agreement was assessed with Cohen's Kappa statistics. RESULTS: The agreement between RNFL and GCIPL was fair in both pre-perimetric (κ=0.25) and perimetric glaucoma (κ=0.21). Agreements between RNFL or GCIPL and optic nerve head parameters (rim area and vertical cup-to-disk ratio; VCDR) were inconclusive due to insufficient data ( P >0.05). Combining GCIPL and rim area agreed fairly with RNFL both in pre-perimetric (κ=0.21) and perimetric glaucoma (κ=0.33). The best classification agreement (moderate) was achieved with the comparison of RNFL-rim area versus VCDR (κ=0.48 in pre-perimetric, 0.45 in perimetric glaucoma). There were no significant differences between pre-perimetric and perimetric glaucoma coefficients of classification agreement. CONCLUSIONS: The normative database diagnostic agreements between optic disk, RNFL, and GCIPL were mostly fair in both pre-perimetric and early perimetric glaucoma. Clinicians should not wait for multiple structures to show abnormality on OCT to diagnose early glaucoma.

Decision Factors for Glaucoma Suspects and Ocular Hypertensive Treatment at an Academic Center.

Aims and background: Practice guidelines assert that high-risk glaucoma suspects should be treated. Yet, there is ambiguity regarding what constitutes a high enough risk for treatment. The purpose of this study was to determine which factors contribute to the decision to treat glaucoma suspects and ocular hypertensive patients in an academic ophthalmology practice. Materials and methods: Retrospective cohort study of glaucoma suspects or ocular hypertensives at an academic ophthalmology practice from 2014 to 2020. Demographics, comorbidities, intraocular pressure (IOP), optical coherence tomography (OCT) findings, and visual field measurements were compared between treated and untreated patients. A multivariable logistic regression model assessed predictors of glaucoma suspected treatment. Results: Of the 388 patients included, 311 (80%) were untreated, and 77 (20%) were treated. There was no statistical difference in age, race/ethnicity, family history of glaucoma, central corneal thickness (CCT), or any visual field parameters between the two groups. Treated glaucoma suspects had higher IOP, thinner retinal nerve fiber layers (RNFL), more RNFL asymmetry, thinner ganglion cell-inner plexiform layers (GCIPL), and a higher prevalence of optic disc drusen, disc hemorrhage, ocular trauma, and proliferative diabetic retinopathy (PDR) (p < 0.05 for all). In the multivariable model, elevated IOP {odds ratio [OR] 1.16 [95% confidence interval (CI) 1.04-1.30], p = 0.008}, yellow temporal [5.76 (1.80-18.40), p = 0.003] and superior [3.18 (1.01-10.0), p = 0.05] RNFL quadrants, and a history of optic disc drusen [8.77 (1.96-39.34), p = 0.005] were significant predictors of glaucoma suspect treatment. Conclusion: Higher IOP, RNFL thinning, and optic disc drusen were the strongest factors in the decision to treat a glaucoma suspect or ocular hypertensive patient. RNFL asymmetry, GCIPL thinning, and ocular comorbidities may also factor into treatment decisions. Clinical significance: Understanding the clinical characteristics that prompt glaucoma suspect treatment helps further define glaucoma suspect disease status and inform when treatment should be initiated. How to cite this article: Ciociola EC, Anderson A, Jiang H, et al. Decision Factors for Glaucoma Suspects and Ocular Hypertensive Treatment at an Academic Center. J Curr Glaucoma Pract 2023;17(3):157-165.

Glaucoma diagnostic accuracy of ganglion cell-inner plexiform layer thickness: comparison with nerve fiber layer and optic nerve head.

PURPOSE: To determine the diagnostic performance of macular ganglion cell-inner plexiform layer (GCIPL) thickness measured with the Cirrus high-definition optical coherence tomography (HD-OCT) ganglion cell analysis (GCA) algorithm (Carl Zeiss Meditec, Dublin, CA) to discriminate normal eyes and eyes with early glaucoma and to compare it with that of peripapillary retinal nerve fiber layer (RNFL) thickness and optic nerve head (ONH) measurements. DESIGN: Evaluation of diagnostic test or technology. PARTICIPANTS: Fifty-eight patients with early glaucoma and 99 age-matched normal subjects. METHODS: Macular GCIPL and peripapillary RNFL thicknesses and ONH parameters were measured in each participant, and their diagnostic abilities were compared. MAIN OUTCOME MEASURES: Area under the curve (AUC) of the receiver operating characteristic. RESULTS: The GCIPL parameters with the best AUCs were the minimum (0.959), inferotemporal (0.956), average (0.935), superotemporal (0.919), and inferior sector (0.918). There were no significant differences between these AUCs and those of inferior quadrant (0.939), average (0.936), and superior quadrant RNFL (0.933); vertical cup-to-disc diameter ratio (0.962); cup-to-disc area ratio (0.933); and rim area (0.910), all P>0.05. CONCLUSIONS: The ability of macular GCIPL parameters to discriminate normal eyes and eyes with early glaucoma is high and comparable to that of the best peripapillary RNFL and ONH parameters. FINANCIAL DISCLOSURE(S): Proprietary or commercial disclosure may be found after the references.

Vision-related Quality of Life in Congolese Patients with Glaucoma.

Purpose: To assess the vision-related quality of life (QoL) in Congolese patients with glaucoma and its associated factors. Methods: Ninety-four patients with open-angle glaucoma and 42 age-matched controls were included in the study. QoL was evaluated using the 25-item National Eye Institute Visual Function Questionnaire (NEI VFQ-25). QoL scores were compared between patients and controls. Correlation analysis was run to assess the association of QoL scores with visual function measures. Multivariate linear regression analyses were used to identify demographic and clinical factors that independently predict the overall QoL and its subdomains. Results: The QoL composite score (QoL-CS) of glaucoma patients (60.2 ± 30.5) was 31.7% lower than that of controls (87.9 ± 9.5), p < 0.001. QoL subdomain scores were also significantly lower in glaucoma patients than controls (all p < 0.001), with a reduction rate oscillating between 16.5% for color vision and 61.1% for general health. Best-corrected visual acuity (BCVA) of both better seeing eye (BSE) and worst seeing eye (WSE) correlated significantly with QoL-CS (variance: 50.4% and 42.3%, respectively). The correlations of QoL-CS with BSE (variance: 12.9%) and WSE (variance: 16.8%) visual field MD were also significant, but the strengths were weaker than those of BCVA. Every increase of BSE's BCVA by one line improved QoL-CS by 43.4. Conclusion: Vision-related quality of life in glaucoma patients is significantly impaired in Congolese patients with glaucoma, starting in the early stage of the disease. BCVA of the BSE emerged as an independent significant predictor of overall QoL and most of its components. How to cite this article: Kapinga IK, Kayembe DL, Mwanza JC. Vision-related Quality of Life in Congolese Patients with Glaucoma. J Curr Glaucoma Pract 2022;16(1):24-30.

Interocular Symmetry and Repeatability of Central Corneal Thickness and Corneal Endothelial Cell Morphology and Density in Healthy Eyes of Congolese.

PURPOSE: To determine the limits of normal interocular symmetry and the repeatability of central corneal thickness (CCT) and endothelial cell morphology and density. METHODS: Two hundred and seventy-eight subjects (age: 10.9-80.7 years) with healthy eyes were studied. CCT as well as endothelial cell morphology and density were measured by non-contact specular microscopy. Three measurements were obtained per eye per participant. Upper and lower tolerance limits of normal interocular symmetry were defined as the 2.5th and 97.5th percentiles of the interocular differences in CCT, endothelial cell density (CECD), coefficient of variation (CoV), hexagonality, and cell size. Repeatability was determined using the intraclass coefficient correlation (ICC), the coefficient of variation (CV), and the test-retest variability standard deviation (TRTSD). RESULTS: The mean interocular differences were -1.05 ± 17.5 µm (p = .32) for CCT and 0.5 ± 90.8 cells/mm2 (p = .76) for CECD. The 2.5th and 97.5th percentiles of the interocular differences were -13.9 and 15.4 µm for CCT and -177.4 cells/mm2 to 182.0 cells/mm2 for CECD. Only interocular difference in CoV correlated weakly with age (r = -0.22, P < .001). ICCs were 0.93 (95% CI: 0.89-0.96, P < .001) for CCT and 0.95 (0.94-0.96, P < .001) for CECD. CV and TRTSD were 1.2% ± 5.3% and 4.4 ± 3.4 µm for CCT and 2.4% ± 3.9% and 17.7 ± 7.7 cells/mm2 for CECD, respectively. CONCLUSIONS: CCT and CECD showed good repeatability and interocular symmetry in normal Congolese subjects. Absolute interocular differences in CCT and CECD exceeding 15.5 µm and 182 cells/mm2, respectively, should be considered suspicious and investigated. When comparing two intrasession measurements from the same eye, a difference of approximately 4.5 µm in CCT and 18 cells/mm2 or greater may be considered statistically significant.

Glaucoma Screening Using an iPad-Based Visual Field Test in a West African Population.

PURPOSE: To investigate the performance of the Melbourne Rapid Fields (MRF) for use in clinic-based visual field testing in a low-resource setting. DESIGN: Prospective cross-sectional study. PARTICIPANTS: One hundred and three participants (66 patients with glaucoma and 37 control participants) attending a clinical appointment at the Tema Eye Center, Tema, Ghana. METHODS: Patients with glaucoma and control participants underwent MRF and Humphrey Field Analyzer (HFA) testing. MAIN OUTCOME MEASURES: Mean deviation (MD), pattern standard deviation (PSD), reliability parameters, sensitivity, specificity, and area under the receiver operating characteristic curve. RESULTS: Mean MD was less negative and mean PSD was more positive on the MRF than the HFA in both groups (all P < 0.001). False-positive and false-negative rates were comparable between methods (P = 0.09 and P = 0.35, respectively). In patients with glaucoma, MD and PSD from the 2 devices were correlated strongly (r = 0.84; P < 0.001) and moderately (r = 0.61; P < 0.001), respectively. Agreement analysis revealed that MRF tended to generate significantly higher MD (bias, 3.3 ± 4.1 dB; P = 0.03) and PSD (bias, 1.9 ± 2.8 dB; P = 0.03) with wide limits of agreement. For detecting moderate to advanced glaucoma, the sensitivity was 60.9% for the MRF and 78.3% for the HFA (P = 0.10); respective specificities were 86.5% and 83.8% (P = 0.76). CONCLUSIONS: The MRF underestimated MD and overestimated PSD values compared with the HFA. Agreement biases were significant, suggesting a weak agreement between the 2 devices. However, the MRF showed potential for screening in a low-resource setting, particularly for detecting moderate to advanced glaucoma.

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.

Ability of cirrus HD-OCT optic nerve head parameters to discriminate normal from glaucomatous eyes.

PURPOSE: To determine the ability of optic nerve head (ONH) parameters measured with spectral domain Cirrus HD-OCT (Carl Zeiss Meditec, Inc., Dublin, CA) to discriminate between normal and glaucomatous eyes and to compare them with the discriminating ability of peripapillary retinal nerve fiber layer (RNFL) thickness measurements performed with Cirrus HD-OCT. DESIGN: Evaluation of diagnostic test or technology. PARTICIPANTS: Seventy-three subjects with glaucoma and 146 age-matched normal subjects. METHODS: Peripapillary ONH parameters and RNFL thickness were measured in 1 randomly selected eye of each participant within a 200 × 200 pixel A-scan acquired with Cirrus HD-OCT centered on the ONH. MAIN OUTCOME MEASURES: Optic nerve head topographic parameters, peripapillary RNFL thickness, and area under receiver operating characteristic curves (AUCs). RESULTS: To distinguish normal from glaucomatous eyes, regardless of disease stage, the 6 best parameters (expressed as AUC) were vertical rim thickness (VRT, 0.963), rim area (0.962), RNFL thickness at clock-hour 7 (0.957), RNFL thickness of the inferior quadrant (0.953), vertical cup-to-disc ratio (VCDR, 0.951), and average RNFL thickness (0.950). The AUC for distinguishing between normal eyes and eyes with mild glaucoma was greatest for RNFL thickness of clock-hour 7 (0.918), VRT (0.914), rim area (0.912), RNFL thickness of inferior quadrant (0.895), average RNFL thickness (0.893), and VCDR (0.890). There were no statistically significant differences between AUCs for the best ONH parameters and RNFL thickness measurements (P > 0.05). CONCLUSIONS: Cirrus HD-OCT ONH parameters are able to discriminate between normal eyes and eyes with glaucoma or even mild glaucoma. There is no difference in the ability of ONH parameters and RNFL thickness measurement, as measured with Cirrus OCT, to distinguish between normal and glaucomatous eyes.

Neuroretinitis and Juxtapapillary Retinochoroiditis as Atypical Presentations of Ocular Toxoplasmosis.

We report three cases of optic nerve toxoplasmosis, an unusual form of ocular toxoplasmosis. In one patient, the optic nerve involvement occurred in an eye with a toxoplasmic chorioretinal scar and choroidal neovascularization in the supramacular area, subretinal fibrosis, and pigment epithelium detachment. The other two patients had papilledema without healed or active chorioretinal lesions, but both had retinal hemorrhage and macular involvement. The diagnosis was based on clinical examination and elevated serum toxoplasma antibodies. Optical coherence tomography helped uncover the structural chorioretinal changes. All patients were treated with a combination of oral antitoxoplasmic drugs, oral prednisone, and intravitreal injection of bevacizumab. Visual acuity improved in all of them. Optic nerve involvement in ocular toxoplasmosis must be considered when papilledema occurs both in isolation and/or in the presence of an active or scarred chorioretinal lesion.