Blindness from glaucoma is associated with socio-economic deprivation, presumed to reflect poor access to care and poor adherence to treatment.
To determine why people with glaucoma are presenting ...late for treatment and to understand access to glaucoma care. Additionally, we sought to identify what patients and the community know, do and think about the condition and why the poor are the most affected with glaucoma blindness.
Study participants were from four communities and two hospitals in Abuja-FCT and Kaduna State, Nigeria. A total of 120 participants were involved, including 8 focus group discussions, 7 in-depth interviews with blind/visually impaired glaucoma patients, 5 rapid direct observation visits with these patients and 13 exit interviews of glaucoma patients in the hospital. The data were analysed using content analysis, interpreting participant experiences in terms of three key steps conceptualised as important in the care pathway: what it takes to know glaucoma, to reach a diagnosis and to access continued care.
This article presents multiple narratives of accessing and maintaining glaucoma care and how people manage and cope with the disease. People may be presenting late due to structural barriers, which include lack of knowledge and awareness about glaucoma and not finding an appropriately equipped health care facility. What keeps glaucoma patients within the care pathway are a good hospital experience; a support structure involving family, counselling and shared patients' experiences; and an informed choice of treatment, as well as agency. The high cost of purchasing care is a major factor for patients dropping out of treatment.
The findings suggest the need to address economic and social structural drivers as glaucoma presents another case study to demonstrate that poverty is a strong driver for blindness. There is also a need for clear glaucoma care pathways with early case finding in the community, two-way referral/feedback systems, well-equipped glaucoma care hospitals and better eye health care financing.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
Heterogeneity of mitogen-activated protein kinase (MAPK) activation in genetically identical cells, which occurs in response to epidermal growth factor receptor (EGFR) signaling, remains poorly ...understood. MAPK cascades integrate signals emanating from different EGFR spatial locations, including the plasma membrane and endocytic compartment. We previously hypothesized that in EGF-stimulated cells the MAPK phosphorylation (pMAPK) level and activity are largely determined by the spatial organization of the EGFR clusters within the cell. For experimental testing of this hypothesis, we used super-resolution microscopy to define EGFR clusters by receptor numbers (N) and average intracluster distances (d). From these data, we predicted the extent of pMAPK with 85% accuracy on a cell-to-cell basis with control data returning 54% accuracy (P < 0.001). For comparison, the prediction accuracy was only 61% (P = 0.382) when the diffraction-limited averaged fluorescence intensity/cluster was used. Large clusters (N ≥ 3) with d > 50 nm were most predictive for pMAPK level in cells. Electron microscopy revealed that these large clusters were primarily localized to the limiting membrane of multivesicular bodies (MVB). Many tighter packed dimers/multimers (d < 50 nm) were found on intraluminal vesicles within MVBs, where they were unlikely to activate MAPK because of the physical separation. Our results suggest that cell-to-cell differences in N and d contain crucial information to predict EGFR-activated cellular pMAPK levels and explain pMAPK heterogeneity in isogenic cells.
To provide data on prevalence and types of refractive error and the spectacle-wearing rate among adults in Nigeria and the degree to which the need for distance correction could be met by ...off-the-shelf spectacles.
Multistage, stratified, cluster random sampling with probability proportional to size was used to identify a nationally representative sample of 15,027 persons aged ≥40 years. Distance vision was measured using a reduced logMAR tumbling-E chart. All participants underwent autorefraction, and those with presenting acuity of <6/12 in one or both eyes had their corrected acuity measured and underwent detailed clinical examination to determine the cause.
Included in the survey were 13,599 (89.9%) of the 15,122 persons aged ≥40 years who were enumerated. Uncorrected refractive error was responsible for 77.9% of mild visual impairment (<6/12-6/18), 57.1% of moderate visual impairment (<6/18-6/60), 11.3% of severe visual impairment (<6/60-3/60), and 1.4% of blindness (<3/60). The crude prevalence of myopia (≤0.5 D) and high myopia (≤5.0 D) were 16.2% and 2.1%, respectively. Spectacles could improve the vision of 1279 (9.4%) and 882 (6.5%) participants at the 6/12 and 6/18 level, respectively, but only 3.4% and 4.4% of these individuals wore spectacles to the examination site. Approximately 2,140,000 adults in Nigeria would benefit from spectacles that improved their vision from <6/12 to ≥6/12. More than a third of the need could be met by low-cost, off-the-shelf spectacles.
Uncorrected refractive errors are an important cause of visual impairment in Nigeria, and services must be dramatically improved to meet the need.
Purpose: Findings from cross-sectional blindness prevalence surveys are at risk of several biases that cause the study estimate to differ from the 'true' population prevalence. For example, response ...bias occurs when people who participate ('responders') differ from those who do not ('non-responders') in ways that affect prevalence estimates. This study aimed to assess the extent to which response bias is considered and occurs in blindness prevalence surveys in low- and middle-income countries (LMICs).
Methods: We searched MEDLINE, EMBASE and Web of Science for cross-sectional blindness prevalence surveys undertaken in LMICs and published 2009-2017. From included studies, we recorded and descriptively analysed details regarding enumeration processes, response, and non-response, including the impact of non-response on results.
Results: Most (95%) of the 92 included studies reported a response rate (median 91.7%, inter-quartile range 85.9-95.6%). Approximately half clearly described enumeration processes (49%), and reported at least one strategy to increase the response rate (53%); a quarter (23%) statistically compared responders and non-responders. When differential response was assessed, men were more likely to be non-responders than women. Two-thirds (65%) of the time a sociodemographic difference was found between responders and non-responders, a difference in blindness prevalence was also found. Only 13 studies (14%) commented on implications of non-response on prevalence estimates.
Conclusions: Response rates are commonly reported from blindness prevalence surveys, and tend to be high. High response rates reduce-but do not eliminate-the risk of response bias. Assessment and reporting of potential response bias in blindness prevalence surveys could be greatly improved.
Celotno besedilo
Dostopno za:
DOBA, IJS, IZUM, KILJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
Purpose: Globally, particularly in Africa, poor compliance with medication is a major problem in glaucoma management but little is known about follow-up rates among African glaucoma patients. The aim ...of this study was to determine rates of follow-up among glaucoma patients attending a tertiary hospital in southern Nigeria and investigate predictors of poor follow-up.
Methods: Data were extracted from medical records of new glaucoma patients who attended the hospital between June 2011 and May 2013. Socio-demographic and clinical parameters (visual acuity; stage of glaucoma) recorded at diagnosis were extracted using a pre-tested form. Follow-up was defined as good if they had attended within 9 months of the study date, inadequate when the last follow-up was more than 9 months and failed if they did not attend any follow-up or the most recent visit was more than 14 months from the study date. Univariate and multivariable analyses were undertaken to explore predictors of poor follow-up (inadequate plus failed).
Results: Three hundred forty-eight patients were recruited, 54% were male and the mean age was 52.7 (range 16-88) years. Follow-up was as follows: good 28.4%, inadequate 46.6%, failed 25%. Overall, 71.6% had poor follow-up. Independent predictors of poor follow-up were poorer visual acuity (OR 3.85, 95% confidence interval (CI) 1.25-11.80 for visual impairment; OR 4.11, 95% CI 1.32-12.81 for blind) and end-stage glaucoma (OR 3.55 (1.31-9.62), p = 0.01).
Conclusion: Enhanced counselling of patients with moderate to advanced glaucoma and visual impairment is required to improve follow-up and hence glaucoma management.
Celotno besedilo
Dostopno za:
DOBA, IJS, IZUM, KILJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
To describe the clinical features of children with anophthalmos, microphthalmos, and typical coloboma (AMC).
Descriptive, observational, cross-sectional study of the United Kingdom.
A total of 135 ...children with AMC newly diagnosed over an 18-month period beginning in October 2006.
Cases were identified using active surveillance through an established ophthalmic surveillance system. Eligible cases were followed up 6 months after first notification.
Phenotypic characteristics, both ocular and systemic, clinical investigations, causes, and interventions.
A total of 210 eyes (of 135 children) were affected by AMC, of which 153 had isolated coloboma or coloboma with microphthalmos. The most common colobomatous anomaly was a chorioretinal defect present in 109 eyes (71.2%). Some 44% of children were bilaterally visually impaired. Systemic abnormalities were present in 59.7% of children, with craniofacial anomalies being the most common. Children with bilateral disease had a 2.7 times higher odds (95% confidence interval, 1.3-5.5, P = 0.006) of having systemic involvement than unilaterally affected children. Neurologic imaging was the most frequent investigation (58.5%) performed. Less than one third (30.3%) of the children with microphthalmos had ocular axial lengths measured. Eight children had confirmed genetic mutations. Approximately half (49.2%) of the children required ocular intervention.
Colobomatous defects were the most common phenotype within this spectrum of anomalies in the United Kingdom. The high frequency of posterior segment colobomatous involvement means that a dilated fundal examination should be made in all cases. The significant visual and systemic morbidity in affected children underlines the importance of a multidisciplinary approach to management.
Cellular senescence may be a key factor in HIV-related premature biological aging. We assessed features of the corneal endothelium that are known to be associated with biological aging, and cellular ...senescence markers in HIV-infected adults.
Case-control study of 242 HIV-infected adults and 249 matched controls. Using specular microscopy, the corneal endothelium was assessed for features of aging (low endothelial cell density ECD, high variation in cell size, and low hexagonality index). Data were analysed by multivariable regression. CDKN2A expression (a cell senescence mediator) was measured in peripheral blood leukocytes and 8-hydroxy-2'-deoxyguanosine (8-OHDG; an oxidative DNA damage marker) levels were measured in plasma.
The median age of both groups was 40 years. Among HIV-infected adults, 88% were receiving antiretroviral therapy (ART); their median CD4 count was 468 cells/µL. HIV infection was associated with increased odds of variation in cell size (OR = 1.67; 95% CI: 1.00-2.78, p = 0.04). Among HIV-infected participants, low ECD was independently associated with current CD4 count <200 cells/µL (OR = 2.77; 95%CI: 1.12-6.81, p = 0.03). In participants on ART with undetectable viral load, CDKN2A expression and 8-OHDG levels were higher in those with accelerated aging, as reflected by lower ECD.
The corneal endothelium shows features consistent with HIV-related accelerated senescence, especially among those with poor immune recovery.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
HIV infection is associated with an increased risk of age-related morbidity mediated by immune dysfunction, atherosclerosis and inflammation. Changes in retinal vessel calibre may reflect cumulative ...structural damage arising from these mechanisms. The relationship of retinal vessel calibre with clinical and demographic characteristics was investigated in a population of HIV-infected individuals in South Africa.
Case-control study of 491 adults ≥30 years, composed of 242 HIV-infected adults and 249 age- and gender-matched HIV-negative controls. Retinal vessel calibre was measured using computer-assisted techniques to determine mean arteriolar and venular diameters of each eye.
The median age was 40 years (IQR: 35-48 years). Among HIV-infected adults, 87.1% were receiving highly active antiretroviral therapy (HAART) (median duration, 58 months), their median CD4 count was 468 cells/µL, and 84.3% had undetectable plasma viral load. Unadjusted mean retinal arteriolar diameters were 163.67±17.69 µm in cases and 161.34±17.38 µm in controls (p = 0.15). Unadjusted mean venular diameters were 267.77±18.21 µm in cases and 270.81±18.98 µm in controls (p = 0.07). Age modified the effect of retinal arteriolar and venular diameters in relation to HIV status, with a tendency towards narrower retinal diameters in HIV cases but not in controls. Among cases, retinal arteriolar diameters narrowed with increasing duration of HAART, independently of age (167.83 µm <3 years of HAART vs. 158.89 µm >6 years, p-trend = 0.02), and with a HIV viral load >10,000 copies/mL while on HAART (p = 0.05). HIV-related venular changes were not detected.
Narrowing of retinal arteriolar diameters is associated with HAART duration and viral load, and may reflect heightened inflammatory and pro-atherogenic states of the systemic vasculature. Measurement of retinal vascular calibre could be an innovative non-invasive method of estimating vascular risk in HIV-infected individuals.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
The Sustainable Development Goals aim to leave no one behind. We explored the hypothesis that women without a living spouse-including those who are widowed, divorced, separated, and never married-are ...a vulnerable group being left behind by cataract services. Using national cross-sectional blindness surveys from Nigeria (2005-2007;
= 13,591) and Sri Lanka (2012-2014;
= 5779) we categorized women and men by marital status (married/not-married) and place of residence (urban/rural) concurrently. For each of the eight subgroups we calculated cataract blindness, cataract surgical coverage (CSC), and effective cataract surgical coverage (eCSC). Not-married women, who were predominantly widows, experienced disproportionate cataract blindness-in Nigeria they were 19% of the population yet represented 56% of those with cataract blindness; in Sri Lanka they were 18% of the population and accounted for 54% of those with cataract blindness. Not-married rural women fared worst in access to services-in Nigeria their CSC of 25.2% (95% confidence interval, CI 17.8-33.8%) was far lower than the best-off subgroup (married urban men, CSC 80.0% 95% CI 56.3-94.3); in Sri Lanka they also lagged behind (CSC 68.5% 95% CI 56.6-78.9 compared to 100% in the best-off subgroup). Service quality was also comparably poor for rural not-married women-eCSC was 8.9% (95% CI 4.5-15.4) in Nigeria and 37.0% (95% CI 26.0-49.1) in Sri Lanka. Women who are not married are a vulnerable group who experience poor access to cataract services and high cataract blindness. To "leave no one behind", multi-faceted strategies are needed to address their needs.
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