Allen Foster

• London School of Hygiene and Tropical Medicine

Background Retinoblastoma is the most common intraocular malignancy in childhood. Despite one-third of cases occurring in Africa, little is known of the outcomes on the continent. This study aims to explore survival and globe salvage outcomes and identify their risk factors across a large cohort of patients from the African continent. Methods A 3-...

Objective Several artificial intelligence (AI) systems for diabetic retinopathy screening have been validated but there is limited evidence on their performance in real-world settings. This study aimed to assess the performance of an AI software deployed within the diabetic retinopathy screening programme in Dominica. Methods and analysis We condu...

Purpose Globally, disparities exist in retinoblastoma treatment outcomes between high- and low-income countries, but independent analysis of American countries is lacking. We report outcomes of American retinoblastoma patients and explore factors associated with survival and globe salvage. Design Subanalysis of prospective cohort study data. Method...

Background Rates of care abandonment for retinoblastoma (RB) demonstrate significant geographical variation; however, other variables that place a patient at risk of abandoning care remain unclear. This study aims to identify the risk factors for care abandonment across a multinational set of patients. Methods A prospective, observational study of...

Background: Good diabetes mellitus (diabetes) and diabetic retinopathy (DR) management depends on the strength of the health system, prompting us to conduct a health system assessment for diabetes and DR in Kenya. We used diabetes and DR as tracer conditions to assess the strengths and weaknesses in the health system, and potential interventions t...

Background/Objectives Retinoblastoma is a common childhood intraocular malignancy, the bilateral form of which most commonly results from a de novo germline pathogenic variant in the RB1 gene. Both advanced maternal age and decreasing birth order are known to increase the risk of de novo germline pathogenic variants, while the influence of national...

Background We undertook a Grand Challenges in Global Eye Health prioritisation exercise to identify the key issues that must be addressed to improve eye health in the context of an ageing population, to eliminate persistent inequities in health-care access, and to mitigate widespread resource limitations. Methods Drawing on methods used in previou...

Purpose: We aimed to review available data on the incidence of herpes simplex virus (HSV) keratitis and other HSV ocular disease and to estimate the global burden of HSV ocular disease. Methods: We searched Medline and Embase databases to October 2020 for studies reporting on the incidence of HSV ocular disease. Study quality was evaluated using...

On behalf of the Global Retinoblastoma Study Group © The Author(s) 2021 OBJECTIVE: To investigate in a large global sample of patients with retinoblastoma whether sex predilection exists for this childhood eye cancer. METHODS: A cross-sectional analysis including 4351 treatment-naive retinoblastoma patients from 153 countries who presented to 278 t...

Objective To investigate in a large global sample of patients with retinoblastoma whether sex predilection exists for this childhood eye cancer. Methods A cross-sectional analysis including 4351 treatment-naive retinoblastoma patients from 153 countries who presented to 278 treatment centers across the world in 2017. The sex ratio (male/female) in...

Purpose: Cataract surgery, quantity and quality, is an indicator of ophthalmic care. A comprehensive assessment of cataract surgical services has never been carried out in Palestine, including West Bank, Gaza Strip and East Jerusalem. The objective of this study was to estimate the cataract surgical rate in 2015 to and to explore the modes of payme...

Few estimates are available of the need for assistive devices (ADs) in African settings. This study aimed to estimate population-level need for glasses and hearing aids in The Gambia based on (1) clinical impairment assessment, and (2) self-reported AD awareness, and explore the relationship between the two methods. The Gambia 2019 National Eye Hea...

Purpose: Epidemiological data is essential for planning; however, all-age population-based surveys are resource intensive. Rapid Assessment of Cataract Surgical Services methodology was developed in India in 1995 and subsequently promoted by the World Health Organisation for use worldwide. The commonly used Rapid Assessment of Avoidable Blindness (...

If Sustainable Developmental Goal 3 and Universal Health Coverage are to be achieved, functioning is a third health indicator which must be assessed and integrated into global health population-based metrics alongside mortality and morbidity. In this paper, we define functioning according to the International Classification of Functioning, Disabili...

Background: The relationship between lag time and outcomes in retinoblastoma (RB) is unclear. In this study, we aimed to study the effect of lag time between onset of symptoms and diagnosis of retinoblastoma (RB) in countries based on their national-income and analyse its effect on the outcomes. Methods: We performed a prospective study of 692 pat...

Objective The aim of the study was to establish the technical capacities needed to deliver the WHO African Region’s primary eye care package in primary healthcare facilities. Design A two-round Delphi exercise was used to obtain expert consensus on the technical complexity of each component of the package and the technical capacities needed to del...

Background: There is limited evidence on how implementation of peer support interventions influences effectiveness, particularly for individuals with diabetes. We conducted a cluster randomized controlled trial to compare the effectiveness of a peer-led health education package versus usual care to increase uptake of screening for diabetic retinop...

The aim of the study was to assess the availability of assistive technology (AT) for visual impairment and trainers in schools for the blind in Delhi. A cross-sectional study was conducted in 22 of the twenty-four schools (blind) in Delhi. The headteacher of each school was asked about availability of 52 ATs divided into writing, reading, math, sci...

Early diagnosis and treatment of retinoblastoma (Rb), the most common intraocular malignancy, can save both the child's life and vision. However, access to services and hence chances for survival and preserving the eye and its vision vary widely across the globe. Some families have to, or make a choice to, leave their home country to seek planned m...

A simplified grading system for trachoma was published by the World Health Organization (WHO) in 1987. Intended for use by non-specialist personnel working at community level, the system includes five signs, each of which can be present or absent in any eye: (i) trachomatous trichiasis; (ii) corneal opacity; (iii) trachomatous inflammation-follicul...

Background: The travel distance from home to a treatment centre, which may impact the stage at diagnosis, has not been investigated for retinoblastoma, the most common childhood eye cancer. We aimed to investigate the travel burden and its impact on clinical presentation in a large sample of patients with retinoblastoma from Africa and Europe. Me...

Background: People living with diabetes can reduce their risk of vision loss from diabetic retinopathy by attending screening, which enables early detection and timely treatment. The aim of this pilot trial was to assess the feasibility of a full-scale cluster randomized controlled trial of an intervention to increase uptake of retinal examination...

Background: Students with visual loss may benefit from assistive technology (AT) for their educational activities. Aim: To understand the barriers faced in using ATs by students who have heard of ATs and reported needing them, but were not using (acquainted students), at schools for the blind in Delhi. Methods: Two hundred and fifty students were s...

Purpose: People with visual disability need assistive technology to improve their body functioning and performance. The purpose of the present study was to understand the awareness, use and barriers in accessing the assistive technology among young patients attending visual rehabilitation clinic of a tertiary eye care hospital in Delhi. Methods:...

BACKGROUND: This study was undertaken to ascertain the current magnitude and causes of blindness and visual impairment in persons aged 50 years and over and to assess the impact of a 10‑year eye care program in Sokoto State, Nigeria. METHODS: A rapid assessment of avoidable blindness (RAAB) survey (in persons 50 years and over) was conducted in 201...

Background: This study was undertaken to ascertain the current magnitude and causes of blindness and visual impairment in persons aged 50 years and over and to assess the impact of a 10-year eye care program in Sokoto State, Nigeria. Methods: A rapid assessment of avoidable blindness (RAAB) survey (in persons 50 years and over) was conducted in...

Importance Half of all the cases of blindness worldwide are associated with cataract. Cataract disproportionately affects people living in low- and middle-income countries and persons of African descent. Objective To estimate the 6-year cumulative incidence of visually impairing cataract in adult participants in the Nakuru Eye Disease Cohort Study...

Objective To estimate the association between (1) visual impairment (VI) and (2) eye disease and 6-year mortality risk within a cohort of elderly Kenyan people. Design, setting and participants The baseline of the Nakuru Posterior Segment Eye Disease Study was formed from a population-based survey of 4318 participants aged ≥50 years, enrolled in 2...

Background: To understand the awareness and utilization of assistive technology in students at schools for the blind in Delhi. Methods: A cross sectional study was conducted among 250 students selected randomly from 10 blind schools in Delhi. Binocular distance presenting and pinhole vision acuity were assessed using Snellen “E” chart and a multipl...

Background We aimed to develop and evaluate a tool for clubfoot therapists in low resource settings to assess the results of Ponseti treatment of congenital talipes equinovarus, or clubfoot, in children of walking age. Method A literature review and a Delphi process based on the opinions of 35 Ponseti trainers in Africa were used to develop the As...

Purpose: To estimate the prevalence of trachoma in suspected-endemic areas of Chad, and thereby determine whether trachoma is a public health problem requiring intervention. Methods: We divided the suspected-endemic population living in secure districts into 46 evaluation units (EUs), and used the standardized methodologies of the Global Trachoma M...

Purpose: To determine the prevalence of trachoma and water and sanitation coverage in four local government areas (LGAs) of Jigawa State, Nigeria: Birnin Kudu, Buji, Dutse and Kiyawa. Methodology: A population-based cross-sectional survey was conducted in each LGA using Global Trachoma Mapping Project (GTMP) protocols. From each LGA, 25 villages we...

Purpose: We sought to determine the prevalence of trachoma in each local government area (LGA) of Benue State, Nigeria. Methods: Two-stage cluster sampling was used to conduct a series of 23 population-based prevalence surveys. LGAs were the evaluation units surveyed. In each LGA, 25 households were selected in each of 25 clusters, and individuals...

Purpose: Ethiopia is highly trachoma endemic. Baseline mapping was needed in Ethiopia’s Somali Region to guide elimination efforts. Methods: Cross-sectional community-based surveys were conducted in 34 suspected trachoma-endemic woredas, grouped as 14 evaluation units (EUs), using a standardised mapping methodology developed for the Global Trachoma...

Purpose: We set out to estimate the prevalence of trachoma and access to water and sanitation in seven suspected-trachoma-endemic districts of northern Congo, surveyed as a single evaluation unit. Methods: From a complete list of rural villages in the seven districts, we systematically selected 22 with probability proportional to village size. In s...

Purpose: The World Health Organization’s (WHO’s) global trachoma elimination programme recommends mapping of trachoma at district level for planning of elimination activities in affected populations. This study aimed to provide data on trachoma prevalence for the Area Councils of Nigeria’s Federal Capital Territory (FCT). Methods: Using the Global...

Purpose: To determine the prevalence of and risk factors for trachoma in selected local government areas (LGAs) of Kwara State, Nigeria. Methodology: Population-based cross-sectional surveys were conducted in eight LGAs of Kwara State using Global Trachoma Mapping Project (GTMP) protocols. In each LGA, 25 villages were selected using probability-pr...

Purpose: The purpose of these surveys was to determine the prevalence of trachomatous inflammation—follicular (TF) in children aged 1–9 years and trichiasis prevalence in persons aged ≥15 years, in 13 Local Government Areas (LGAs) of Taraba State, Nigeria. Methods: The surveys followed Global Trachoma Mapping Project (GTMP) protocols. Twenty-five h...

Purpose: Trachoma is endemic in parts of Nepal; implementation of the surgery, antibiotics, facial cleanliness, environmental improvement (SAFE) strategy started in 2002. Some suspected-endemic districts had not previously been mapped. We aimed to estimate the prevalences of trachomatous inflammation—follicular (TF) and trichiasis in those district...

Purpose: To assess Eritrea’s progress towards elimination of trachoma as a public health problem, we reviewed and compiled current knowledge on the distribution and burden of trachoma in Eritrea, then undertook further population-based surveys where indicated, with support from the Global Trachoma Mapping Project (GTMP). Methods: For the systematic...

Purpose: In suspected trachoma-endemic areas of Yemen, we sought to determine the prevalence of the sign trachomatous inflammation—follicular (TF) in children aged 1–9 years, and the potential individual and household risk factors for TF in that age group. We also sought to determine the prevalence of trichiasis in adults aged ≥15 years. Methods: W...

Purpose: Trachoma is to be eliminated as a public health problem by 2020. To help the process of planning interventions where needed, and to provide a baseline for later comparison, we set out to complete the map of trachoma in Afar, Ethiopia, by estimating trachoma prevalence in evaluation units (EUs) of grouped districts (“woredas”). Methods: We...

Purpose: Senegal is endemic for trachoma, an infectious and potentially blinding eye disease. To complete the country’s district-level baseline map of trachoma, we conducted population-based surveys in 17 health districts that were suspected-endemic but had yet to be surveyed. Methods: We randomly selected 30 clusters (villages) per district and 30...

Purpose: To determine the prevalence of trachoma in four Local Government Areas (LGAs) of Kogi State, Nigeria. Methods: In June 2014, we conducted population-based, cross-sectional surveys according to Global Trachoma Mapping Project (GTMP) protocols in selected LGAs of Kogi State. In each LGA, 25 clusters were selected with probability proportiona...

Background There are various established scoring systems to assess the outcome of clubfoot treatment after correction with the Ponseti method. We used five measures to compare the results in a cohort of children followed up for between 3.5 to 5 years. Methods In January 2017 two experienced physiotherapists assessed children who had started trea...

Purpose: The effectiveness of school eye health programmes relies on many factors, including compliance with spectacle wear. The objectives of this study were to determine spectacle compliance in a school vision screening pilot programme in Botswana, and investigate factors predictive of compliance. Methods: The study was an observational, cross-se...

The effectiveness of school eye health programmes relies on many factors, including compliance with spectacle wear. The objectives of this study were to determine spectacle compliance in a school vision screening pilot programme in Botswana, and investigate factors predictive of compliance. The study was an observational, cross-sectional follow-up...

Purpose: The quality of cataract surgery delivered in sub-Saharan Africa (SSA) is a significant constraint to achieving the elimination of avoidable blindness. No published reports from routine SSA cataract services attain the WHO benchmarks for visual outcomes; poor outcomes (<6/60) often comprise 20% in published case series. This Delphi exercis...

In collaboration with the health ministries that we serve and other partners, we set out to complete the multiple-country Global Trachoma Mapping Project. To maximize the accuracy and reliability of its outputs, we needed in-built, practical mechanisms for quality assurance and quality control. This article describes how those mechanisms were creat...

Background All patients with diabetes are at risk of developing diabetic retinopathy (DR), a progressive and potentially blinding condition. Early treatment of DR prevents visual impairment and blindness. The natural history of DR is that it is asymptomatic until the advanced stages, thus annual retinal examination is recommended for early detectio...

Background: The use of clinical practice guidelines envisages augmenting quality and best practice in clinical outcomes. Generic guidelines that are not adapted for local use often fail to produce these outcomes. Adaptation is a systematic and rigorous process that should maintain the quality and validity of the guideline, while making it more usa...

Purpose: To describe cataract services in Egypt and explore resources and practices in public and private sectors. Methods: The study was conducted between June and August 2015. All facilities in the country providing cataract services were contacted to obtain information on surgeries performed in 2014. Hospitals performing eye surgery in Quena, Sh...

This study aims to determine the indicators for assessing the functionality of clubfoot clinics in a low-resource setting. Methods: The Delphi method was employed with experienced clubfoot practitioners in Africa to rate the importance of indicators of a good clubfoot clinic. The consistency among the participants was deter- mined with the intracl...

A red reflex test can detect cataract and retinoblastoma. Both conditions require urgent referral.

Purpose: Glaucoma is a leading cause of blindness in people of African descent. Minimal data is available from African population-based cohort studies. The primary aims of this study were to describe the normative distribution of glaucoma features to enable glaucoma classification and to assess risk factors for those with glaucoma at follow-up amo...

Background Congenital talipes equino-varus (CTEV), also known as clubfoot, is one of the most common congenital musculoskeletal malformations. Despite this, considerable variation exists in the measurement of deformity correction and outcome evaluation. This study aims to determine the criteria for successful clubfoot correction using the Ponseti t...

Questionnaire for Delphi 1 round 2. (DOCX)

Questionnaire for Delphi 2 round 2. (DOCX)

Background Diabetic retinopathy (DR) is a significant public health concern that is potentially blinding. Clinical practice guidelines recommend annual eye examination of patients with diabetes for early detection of DR. Our aim was to identify the demand-side factors that influence uptake of eye examination among patients already utilizing diabete...

All persons living with Diabetes Mellitus (DM) have a lifetime risk of developing Diabetic Retinopathy (DR), a potentially blinding microvascular complication of DM. The risk increases with the duration of diabetes. The onset and progression of DR can be delayed through optimization of control of blood glucose, blood pressure and lipids. The risk o...

Background Clubfoot is one of the most common congenital deformities affecting mobility. It leads to pain and disability if untreated. The Ponseti method is widely used for the correction of clubfoot. There is variation in how the result of clubfoot management is measured and reported. This review aims to determine and evaluate how success with the...

Background:Clubfoot is one of the most common congenital deformities affecting mobility. It leads to pain and disability if untreated. The Ponseti method is widely used for the correction of clubfoot. There is variation in how the result of clubfoot management is measured and reported. This review aims to determine and evaluate how success with the...