Multilevel Analysis of Trachomatous Trichiasis and Corneal Opacity in Nigeria : The Role of Environmental and Climatic Risk Factors on the Distribution of Disease.

Funding: Jennifer L Smith was supported by the International Trachoma Initiative through a grant from the Bill and Melinda Gates Foundation. Anthony Solomon is a Wellcome Trust Intermediate Clinical Fellow (098521). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.Peer reviewedPublisher PD

Prevalence, causes, and risk factors for functional low vision in Nigeria: results from the national survey of blindness and visual impairment.

PURPOSE: To estimate prevalence and describe causes of functional low vision (FLV) among a nationally representative sample of Nigerian adults, assess socioeconomic risk factors, and estimate the number of adults in Nigeria who might benefit from low vision assessment or rehabilitation services. METHODS: Multistage, stratified, cluster random sampling with probability proportional to size procedures were used to identify a nationally representative sample of 15,027 persons aged 40 years or older. Distance vision was measured using a reduced logMAR tumbling E-chart. All participants 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. FLV was defined as best corrected vision <6/18 in the better eye, after excluding those with no light perception in both eyes and those with treatable causes. Analysis took account of the clustered design. RESULTS: In all, 13,591 individuals were examined in 305 clusters (response rate, 89.9%). The crude prevalence of FLV was 3.5% (95% confidence interval, 3.1-3.9%). This was lower than the prevalence of blindness, which was 4.2%. Glaucoma was the most common cause and age the most important risk factor. There are estimated to be approximately 5000 adults with FLV per million population and 340 who are totally blind. Only 9.3% of those with FLV were of working age and literate. CONCLUSIONS: These are the first data on the prevalence, causes, and risk factors for FLV from Africa. Results support studies from Asia that the prevalence of FLV is lower than previously thought. Because the majority of adults with FLV in Nigeria live in rural areas and are elderly and not literate, further research is required to assess the nature of the interventions required and who might best deliver them

Hematotoxicity study of the leaf extract of Albizia chevalieri harms (Leguminosae)

Uvod: Postoje izvješća o značajnom hipoglikemijskom učinku vodenog ekstrakta lišća biljke Albizia chevalieri kod dijabetičnih štakora s šećernom bolesti izazvane aloksanom. Materijali i metode: Učinak vodenog ekstrakta lišća Albizia chevalieri na hematološke varijable i patohistološku analizu ispitan je kod štakora kojima su davane akutne i subkronične doze ovoga pripravka. Štakori na akutnim dozama primili su između 0 i 3000 mg/kg tjelesne težine ekstrakta oralno u jednoj dozi, dok su oni na subkroničnim dozama primali između 0 i 1500 mg/kg tjelesne težine na dan kroz 28 dana. Testirani parametri analizirali su se u uzorcima krvi i tkiva na kraju razdoblja promatranja. Rezultati: Ekstrakt nije imao značajnog učinka (P>0,05) na koncentraciju hemoglobina, crvenu krvnu sliku, volumen koncentriranih stanica (engl. packed cell volume, PCV) (hematokrit), bijelu krvnu sliku i diferencijalnu krvnu sliku, te broj trombocita u testu akutne toksičnosti. Nije bilo značajnog učinka na srednji stanični volumen (engl. mean cell volume, MCV), srednju vrijednost staničnog hemoglobina (engl. mean cell hemoglobin, MCH) i srednju koncentraciju staničnog hemoglobina (engl. mean cell hemoglobin concentration, MCHC). kod štakora na akutnim i subkroničnim dozama ekstrakta (P>0,05). U studiji subkronične toksičnosti, PCV, bijela krvna slika i diferencijalna slika (P<0,05) pokazali su značajne i od dozi neovisne razlike od kontrolnih vrijednosti. Pa-tohistološka analiza tkiva jetre, bubrega i srca štakora pokazala je normalne nalaze kako nakon akutnog tako i nakon subkroničnog davanja ekstrakta. Zaključak: Vodeni ekstrakt lišća Albizia chevalieri, za koji je objavljeno da ima značajno hipoglikemijsko djelovanje kod štakora sa šećernom bolesti izazvane aloksanom, mogao bi biti siguran za primjenu u ispitivanim dozama.Background: Aqueous leaf extract of Albizia chevalieri has been reported to have a significant hypoglycemic effect in alloxan induced diabetic rats. Materials and methods: The effects of the aqueous leaf extract on hema-tologic variables and histopathologic analyses were assessed in rats treated with acute and sub-chronic doses. Rats treated with acute doses received between 0 and 3000 mg/kg body weight of the extract orally in a single dose, whereas those treated with sub-chronic doses received between 0 and 1500 mg/kg body weight per day for 28 days. Blood and tissue samples were analyzed for the tested parameters at the end of the observation period. Results: The extract had no significant (P>0.05) effect on hemoglobin concentration, red blood cell count, packed cell volume, white blood cell and differential counts, and platelets count in the acute toxicity test. The mean cell volume (MCV), mean cell hemoglobin (MCH) and mean cell hemoglobin concentration (MCHC) of rats treated with acute and sub-chronic doses of the extract were not significantly (P>0.05) affected. Packed cell volume (PCV), white blood cell (WBC) and differential counts were significantly (P<0.05) different from the control in a non-dose dependent fashion in the sub-chronic toxicity study. Rat liver, kidney and heart tissues analyzed histopathologically were normal upon both acute and sub-chronic administration of the extract. Conclusion: Aqueous leaf extract of A. chevalieri, which has been reported to have a significant hypoglycemic effect in alloxan diabetic rats, might be safe in the tested doses

Changing patterns of cataract services in North-West Nigeria: 2005-2016.

PURPOSE: This study was conducted to assess the impact of the eye care programme on cataract blindness and cataract surgical services in Sokoto, Nigeria over a 12 year period 2005-2016. METHODS: Data from the 2005 population based cross-sectional study of blindness in Sokoto state was re-analysed to obtain baseline estimates of the prevalence of cataract blindness and cataract surgical coverage for persons 50 years and over in Wurno health zone. A population based survey of a representative sample of persons 50 years and over in Wurno health zone was conducted in July 2016. Data on eye health workforce, infrastructure and cataract surgical services between 2005 and 2016 were analysed from relevant documents. RESULTS: In 2005 the unadjusted prevalence of bilateral cataract blindness (<3/60) in people 50 years and over in Wurno health zone was 5.6% (95% CI: 3.1, 10.1). By 2016 this had fallen to 2.1% (95% CI 1.5%, 2.7%), with the age-sex adjusted prevalence being 1.9% (95% CI 1.3%, 2.5%). The CSC for persons with visual acuity <3/60, <6/60, <6/18 for Wurno health zone was 9.1%, 7.1% and 5.5% respectively in 2005 and this had increased to 67.3%, 62.1% and 34.7% respectively in 2016. The CSR in Sokoto state increased from 272 (1005 operations) in 2006, to 596 (2799 operations) in 2014. In the 2005 survey, couching (a procedure used by traditional practitioners to dislocate the lens into the vitreous cavity) accounted for 87.5% of all cataract interventions, compared to 45.8% in the 2016 survey participants. In 2016 18% of eyes having a cataract operation with IOL implantation had a presenting visual acuity of <6/60 (poor outcome) with the main causes being postoperative complications (53%) and uncorrected refractive error (29%). CONCLUSION: Between 2005 and 2016 there was a doubling in cataract surgical rate, a 7 times increase in cataract surgical coverage (<3/60), and a decrease in cataract blindness and the proportion of eyes being couched. However, there remains a high prevalence of un-operated cataract in 2016 indicating a need to further improve access to affordable and good quality cataract surgical services

Changing patterns of cataract services in North-West Nigeria: 2005-2016.

PURPOSE: This study was conducted to assess the impact of the eye care programme on cataract blindness and cataract surgical services in Sokoto, Nigeria over a 12 year period 2005-2016. METHODS: Data from the 2005 population based cross-sectional study of blindness in Sokoto state was re-analysed to obtain baseline estimates of the prevalence of cataract blindness and cataract surgical coverage for persons 50 years and over in Wurno health zone. A population based survey of a representative sample of persons 50 years and over in Wurno health zone was conducted in July 2016. Data on eye health workforce, infrastructure and cataract surgical services between 2005 and 2016 were analysed from relevant documents. RESULTS: In 2005 the unadjusted prevalence of bilateral cataract blindness (<3/60) in people 50 years and over in Wurno health zone was 5.6% (95% CI: 3.1, 10.1). By 2016 this had fallen to 2.1% (95% CI 1.5%, 2.7%), with the age-sex adjusted prevalence being 1.9% (95% CI 1.3%, 2.5%). The CSC for persons with visual acuity <3/60, <6/60, <6/18 for Wurno health zone was 9.1%, 7.1% and 5.5% respectively in 2005 and this had increased to 67.3%, 62.1% and 34.7% respectively in 2016. The CSR in Sokoto state increased from 272 (1005 operations) in 2006, to 596 (2799 operations) in 2014. In the 2005 survey, couching (a procedure used by traditional practitioners to dislocate the lens into the vitreous cavity) accounted for 87.5% of all cataract interventions, compared to 45.8% in the 2016 survey participants. In 2016 18% of eyes having a cataract operation with IOL implantation had a presenting visual acuity of <6/60 (poor outcome) with the main causes being postoperative complications (53%) and uncorrected refractive error (29%). CONCLUSION: Between 2005 and 2016 there was a doubling in cataract surgical rate, a 7 times increase in cataract surgical coverage (<3/60), and a decrease in cataract blindness and the proportion of eyes being couched. However, there remains a high prevalence of un-operated cataract in 2016 indicating a need to further improve access to affordable and good quality cataract surgical services

Prevalence and risk factors for lens opacities in Nigeria: results of the national blindness and low vision survey.

PURPOSE: Investigate prevalence and risk factors for lens opacities among a nationally representative sample of Nigerians aged ≥ 40 years. METHODS: Across 305 clusters, 13,591 adults were examined. Every seventh participant (n = 1722) was sampled systematically and examined in detail, including lens opacity grading. Lenses were examined at the slit-lamp with pupil dilation and graded using the World Health Organization (WHO) system. Significant opacities were defined as nuclear, cortical, or posterior subcapsular opacity of WHO grade >1, or hyper/mature cataract. The category "Any Opacity" included hyper/mature opacity and aphakia/pseudophakia/couching. Data were collected on sociodemographic and environmental factors, including height and weight. RESULTS: A total of 1631/1722 (95%) in the normative subsample had their lenses graded. Prevalence of "Any Opacity" was 19.8% (95% confidence interval [CI]: 7.9-21.7) the prevalence of all types increased with age, and was higher in females and those not literate. Prevalence of nuclear, cortical, and posterior subcapsular were 8.8% (95% CI: 7.5-10.1); 11.7% (95% CI: 10.0-13.3); and 2.9% (95% CI: 2.1-3.8), respectively. In multivariate analysis, age was an independent risk factor for all types. Nuclear opacity was also associated with female sex (odds ratio [OR] 2.4; 95% CI: 1.5-3.6); lean body mass index (BMI; OR 2.0; 95% CI: 1.1-3.5); and the Igbo ethnic group (OR 4.4; 95% CI: 2.3-8.4). Cortical opacity was also associated with female sex (OR 2.1; 95% CI: 1.5-3.0) and the Yoruba (OR 0.45; 95% CI: 0.3-0.8), but not with BMI. "Other Lens Opacities," which includes couching, was significantly lower in the Guinea savannah region (OR 0.4; 95% CI: 0.2-0.9), while living in rain forest areas was protective for posterior subcapsular cataracts (OR 0.3; 95% CI: 0.1-0.7). CONCLUSIONS: A fifth of Nigerian adults have some degree of lens opacity. Further studies are needed to investigate the role of ethnicity, climate variables, and other risk factors

A Population-based survey of the prevalence and types of glaucoma in Nigeria: results from the Nigeria National Blindness and Visual Impairment Survey.

BACKGROUND: Glaucoma is the leading cause of irreversible blindness worldwide. There tends to be a lower reporting of glaucoma in Africa compared to other blinding conditions in global burden data. Research findings of glaucoma in Nigeria will significantly increase our understanding of glaucoma in Nigeria, in people of the West African diaspora and similar population groups. We determined the prevalence and types of glaucoma in Nigeria from the Nigeria National Blindness and Visual Impairment cross-sectional Survey of adults aged ≥40 years. METHODS: Multistage stratified cluster random sampling with probability-proportional-to-size procedures were used to select a nationally representative sample of 15,027 persons aged ≥40 years. Participants had logMAR visual acuity measurement, FDT visual function testing, autorefraction, A-scan biometry and optic disc assessment. Participants with visual acuity of worse than 6/12 or suspicious optic discs had detailed examination including Goldmann applanation tonometry, gonioscopy and fundus photography. Disc images were graded by Moorfields Eye Hospital Reading Centre. Glaucoma was defined using International Society of Geographical and Epidemiological Ophthalmology criteria; and classified into primary open-angle or primary angle-closure or secondary glaucoma. Diagnosis of glaucoma was based on ISGEO classification. The type of glaucoma was determined by gonioscopy. RESULTS: A total of 13,591 participants in 305 clusters were examined (response rate 90.4 %). Optic disc grading was available for 25,289 (93 %) eyes of 13,081 (96 %) participants. There were 682 participants with glaucoma; a prevalence of 5.02 % (95 % CI 4.60-5.47). Among those with definite primary glaucoma that had gonioscopy (n = 243), open-angle glaucoma was more common (86 %) than angle-closure glaucoma (14 %). 8 % of glaucoma was secondary with the commonest causes being couching (38 %), trauma (21 %) and uveitis (19 %). Only 5.6 % (38/682) of participants with glaucoma knew they had the condition. One in every 5 persons with glaucoma (136;20 %) was blind i.e., visual acuity worse than 3/60. CONCLUSION: Nigeria has a high prevalence of glaucoma which is largely open-angle glaucoma. A high proportion of those affected are blind. Secondary glaucoma was mostly as a consequence of procedures for cataract. Public health control strategies and high quality glaucoma care service will be required to reduce morbidity and blindness from glaucoma

Strengthening the integration of eye care into the health system: methodology for the development of the WHO package of eye care interventions.

OBJECTIVE: To describe the rational for, and the methods that will be employed to develop, the WHO package of eye care interventions (PECI). METHODS AND ANALYSIS: The development of the package will be conducted in four steps: (1) selection of eye conditions (for which interventions will be included in the package) based on epidemiological data on the causes of vision impairment and blindness, prevalence estimates of eye conditions and health facility data; (2) identification of interventions and related evidence for the selected eye conditions from clinical practice guidelines and high-quality systematic reviews by a technical working group; (3) expert agreement on the inclusion of eye care interventions in the package and the description of resources required for the provision of the selected interventions; and (4) peer review. The project will be led by the WHO Vision Programme in collaboration with Cochrane Eyes and Vision. A Technical Advisory Group, comprised of public health and clinical experts in the field, will provide technical input throughout all stages of development. RESULTS: After considering the feedback of Technical Advisory Group members and reviewing-related evidence, a final list of eye conditions for which interventions will be included in the package has been collated. CONCLUSION: The PECI will support Ministries of Health in prioritising, planning, budgeting and integrating eye care interventions into health systems. It is anticipated that the PECI will be available for use in 2021

Keeping an eye on eye care: monitoring progress towards effective coverage

The eye care sector is well positioned to contribute to the advancement of universal health coverage within countries. Given the large unmet need for care associated with cataract and refractive error, coupled with the fact that highly cost-effective interventions exist, we propose that effective cataract surgery coverage (eCSC) and effective refractive error coverage (eREC) serve as ideal indicators to track progress in the uptake and quality of eye care services at the global level, and to monitor progress towards universal health coverage in general. Global targets for 2030 for these two indicators were endorsed by WHO Member States at the 74th World Health Assembly in May, 2021. To develop consensus on the data requirements and methods of calculating eCSC and eREC, WHO convened a series of expert consultations to make recommendations for standardising the definitions and measurement approaches for eCSC and eREC and to identify areas in which future work is required