The global burden of trichiasis in 2016.

BACKGROUND: Trichiasis is present when one or more eyelashes touches the eye. Uncorrected, it can cause blindness. Accurate estimates of numbers affected, and their geographical distribution, help guide resource allocation. METHODS: We obtained district-level trichiasis prevalence estimates in adults for 44 endemic and previously-endemic countries. We used (1) the most recent data for a district, if more than one estimate was available; (2) age- and sex-standardized corrections of historic estimates, where raw data were available; (3) historic estimates adjusted using a mean adjustment factor for districts where raw data were unavailable; and (4) expert assessment of available data for districts for which no prevalence estimates were available. FINDINGS: Internally age- and sex-standardized data represented 1,355 districts and contributed 662 thousand cases (95% confidence interval [CI] 324 thousand-1.1 million) to the global total. Age- and sex-standardized district-level prevalence estimates differed from raw estimates by a mean factor of 0.45 (range 0.03-2.28). Previously non- stratified estimates for 398 districts, adjusted by ×0.45, contributed a further 411 thousand cases (95% CI 283-557 thousand). Eight countries retained previous estimates, contributing 848 thousand cases (95% CI 225 thousand-1.7 million). New expert assessments in 14 countries contributed 862 thousand cases (95% CI 228 thousand-1.7 million). The global trichiasis burden in 2016 was 2.8 million cases (95% CI 1.1-5.2 million). INTERPRETATION: The 2016 estimate is lower than previous estimates, probably due to more and better data; scale-up of trichiasis management services; and reductions in incidence due to lower active trachoma prevalence

Sanitation and water supply coverage thresholds associated with active trachoma: Modeling cross-sectional data from 13 countries.

BACKGROUND: Facial cleanliness and sanitation are postulated to reduce trachoma transmission, but there are no previous data on community-level herd protection thresholds. We characterize associations between active trachoma, access to improved sanitation facilities, and access to improved water sources for the purpose of face washing, with the aim of estimating community-level or herd protection thresholds. METHODS AND FINDINGS: We used cluster-sampled Global Trachoma Mapping Project data on 884,850 children aged 1-9 years from 354,990 households in 13 countries. We employed multivariable mixed-effects modified Poisson regression models to assess the relationships between water and sanitation coverage and trachomatous inflammation-follicular (TF). We observed lower TF prevalence among those with household-level access to improved sanitation (prevalence ratio, PR = 0.87; 95%CI: 0.83-0.91), and household-level access to an improved washing water source in the residence/yard (PR = 0.81; 95%CI: 0.75-0.88). Controlling for household-level water and latrine access, we found evidence of community-level protection against TF for children living in communities with high sanitation coverage (PR80-90% = 0.87; 95%CI: 0.73-1.02; PR90-100% = 0.76; 95%CI: 0.67-0.85). Community sanitation coverage levels greater than 80% were associated with herd protection against TF (PR = 0.77; 95%CI: 0.62-0.97)-that is, lower TF in individuals whose households lacked individual sanitation but who lived in communities with high sanitation coverage. For community-level water coverage, there was no apparent threshold, although we observed lower TF among several of the higher deciles of community-level water coverage. CONCLUSIONS: Our study provides insights into the community water and sanitation coverage levels that might be required to best control trachoma. Our results suggest access to adequate water and sanitation can be important components in working towards the 2020 target of eliminating trachoma as a public health problem

Intermediate-term cataract surgery outcomes from rural provinces in Lao People's Democratic Republic

Published online: 28 Jul 2015PURPOSE: Limited data are available about cataract surgery outcomes from developing regions in South-East Asia, but are necessary to monitor the impact of ongoing program delivery as outlined in the World Health Organization Vision 2020 directives. METHODS: We conducted a retrospective cohort study of 488 eyes of 449 patients who had undergone cataract surgery in 2011 in Luang Prabang and Xayaboury provinces of northwestern Lao People's Democratic Republic (Lao PDR). The study included 400 eyes of 361 subjects (80.4% of the target population). The main outcomes were presenting and pinhole visual acuity (VA). RESULTS: Subjects' mean age was 68 years (standard deviation 12.1 years); 52.6% were women. Preoperative presenting VA in the operated eye was 6/18 in 185/400 eyes (46.3%, 95% confidence interval, CI, 41.4-51.2%), <6/18-6/60 in 177/400 (44.3%, 95% CI 39.4-49.2%) and <6/60 in 38/400 (9.5%, 95% CI 6.6-12.4%). VA improved two or more lines in 61/400 eyes (15.3%, 95% CI 11.7-18.8%) with pinhole. Relative afferent pupillary defect was present in 13/400 eyes (3.3%, 95% CI 1.5-5.0%). CONCLUSION: Presenting postoperative VA did not meet the World Health Organization criteria for good outcomes. Further study is required to determine specific factors contributing to adverse outcomes in this population.Melissa Kate Shields, Robert J. Casson, James Muecke, Sengla Laosern, Phoumpanya Louangsouksa, Somchit Vannavong, and Khamphoua Southisombat

Causes of severe visual impairment and blindness: comparative data from Bhutanese and Laotian schools for the blind

Purpose: To determine and compare the major causes of childhood blindness and severe visual impairment in Bhutan and Laos. Design: Independent cross-sectional surveys. Methods: This survey consists of 2 cross-sectional observational studies. The Bhutanese component was undertaken at the National Institute for Vision Impairment, the only dedicated school for the blind in Bhutan. The Laotian study was conducted at the National Ophthalmology Centre and Vientiane School for the Blind. Children younger than age 16 were invited to participate. A detailed history and examination were performed consistent with the World Health Organization Prevention of Blindness Eye Examination Record. Results: Of the 53 children examined in both studies, 30 were from Bhutan and 23 were from Laos. Forty percent of Bhutanese and 87.1% of Laotian children assessed were blind, with 26.7% and 4.3%, respectively, being severely visually impaired. Congenital causes of blindness were the most common, representing 45% and 43.5% of the Bhutanese and Laotian children, respectively. Anatomically, the primary site of blinding pathology differed between the cohorts. In Bhutan, the lens comprised 25%, with whole globe at 20% and retina at 15%, but in Laos, whole globe and cornea equally contributed at 30.4%, followed by retina at 17.4%. There was an observable difference in the rates of blindness/severe visual impairment due to measles, with no cases observed in the Bhutanese children but 20.7% of the total pathologies in the Laotian children attributable to congenital measles infection. Conclusions: Consistent with other studies, there is a high rate of blinding disease, which may be prevented, treated, or ameliorated.Lachlan David Mailey Farmer, Soo Khai Ng, Adam Rudkin, Jamie Craig, Dechen Wangmo, Hughie Tsang, Khamphoua Southisombath, Andrew Griffiths and James Mueck

Multivariable model showing the household-level and community-level associations between sanitation, water and trachomatous inflammation—Follicular (TF) among children aged 1–9 years.

<p>Multivariable model showing the household-level and community-level associations between sanitation, water and trachomatous inflammation—Follicular (TF) among children aged 1–9 years.</p

Results from multivariable interaction model showing the association between community-level sanitation coverage and water coverage on trachomatous inflammation—Follicular prevalence, stratified by household access to sanitation or water among children aged 1–9 years.

<p>Results from multivariable interaction model showing the association between community-level sanitation coverage and water coverage on trachomatous inflammation—Follicular prevalence, stratified by household access to sanitation or water among children aged 1–9 years.</p

Study flow diagram.

<p>Study flow diagram.</p

Association between trachomatous inflammation—Follicular in children aged 1–9 years and both household and community associations combined together (i.e. the “total effect”).

<p>The reference group is participants without household washing water/sanitation living in the lowest coverage decile.</p

Results from multivariable model showing the association between community-level sanitation and water coverage on trachomatous inflammation—Follicular prevalence among children aged 1–9 years.

<p>Results from multivariable model showing the association between community-level sanitation and water coverage on trachomatous inflammation—Follicular prevalence among children aged 1–9 years.</p