Final Measurement of the ^{235}U Antineutrino Energy Spectrum with the PROSPECT-I Detector at HFIR

This Letter reports one of the most precise measurements to date of the antineutrino spectrum from a purely ^{235}U-fueled reactor, made with the final dataset from the PROSPECT-I detector at the High Flux Isotope Reactor. By extracting information from previously unused detector segments, this analysis effectively doubles the statistics of the previous PROSPECT measurement. The reconstructed energy spectrum is unfolded into antineutrino energy and compared with both the Huber-Mueller model and a spectrum from a commercial reactor burning multiple fuel isotopes. A local excess over the model is observed in the 5-7 MeV energy region. Comparison of the PROSPECT results with those from commercial reactors provides new constraints on the origin of this excess, disfavoring at 2.0 and 3.7 standard deviations the hypotheses that antineutrinos from ^{235}U are solely responsible and noncontributors to the excess observed at commercial reactors, respectively.

Improved screening of retinopathy of prematurity (ROP): development of a target product profile (TPP) for resource-limited settings

BACKGROUND

As more preterm infants survive, complications of preterm birth, including retinopathy of prematurity (ROP), become more prevalent. ROP rates and blindness from ROP are higher in low-income and middle-income countries, where exposure to risk factors can be higher and where detection and treatment of ROP are under-resourced or non-existent. Access to low-cost imaging devices would improve remote screening capabilities for ROP.

METHODS

Target product profiles (TPPs) are developed early in the medical device development process to define the setting, target user and range of product requirements. A Delphi-like process, consisting of an online survey and consensus meeting, was used to develop a TPP for an ROP imaging device, collecting feedback on a proposed set of 64 product requirements.

RESULTS

Thirty-six stakeholders from 17 countries provided feedback: clinicians (72%), product developers (14%), technicians (6%) and other (8%). Thirty-six per cent reported not currently screening for ROP, with cited barriers including cost (44%), no training (17%) and poor image quality (16%). Among those screening (n=23), 48% use more than one device, with the most common being an indirect ophthalmoscope (87%), followed by RetCam (26%) and smartphone with image capture (26%). Consensus was reached on 53 (83%) product requirements. The 11 remaining were discussed at the consensus meeting, and all but two achieved consensus.

CONCLUSIONS

This TPP process was novel in that it successfully brought together diverse stakeholders to reach consensus on the product requirements for an ROP imaging devices. The resulting TPP provides a framework from which innovators can develop prototypes.

Cataract services for all: Strategies for equitable access from a global modified Delphi process

Vision loss from cataract is unequally distributed, and there is very little evidence on how to overcome this inequity. This project aimed to engage multiple stakeholder groups to identify and prioritise (1) delivery strategies that improve access to cataract services for under-served groups and (2) population groups to target with these strategies across world regions. We recruited panellists knowledgeable about cataract services from eight world regions to complete a two-round online modified Delphi process. In Round 1, panellists answered open-ended questions about strategies to improve access to screening and surgery for cataract, and which population groups to target with these strategies. In Round 2, panellists ranked the strategies and groups to arrive at the final lists regionally and globally. 183 people completed both rounds (46% women). In total, 22 distinct population groups were identified. At the global level the priority groups for improving access to cataract services were people in rural/remote areas, with low socioeconomic status and low social support. South Asia and Sub-Saharan Africa were the only regions in which panellists ranked women in the top 5 priority groups. Panellists identified 16 and 19 discreet strategies to improve access to screening and surgical services, respectively. These mostly addressed health system/supply side factors, including policy, human resources, financing and service delivery. We believe these results can serve eye health decision-makers, researchers and funders as a starting point for coordinated action to improve access to cataract services, particularly among population groups who have historically been left behind.

Experimental Search for Neutron to Mirror Neutron Oscillations as an Explanation of the Neutron Lifetime Anomaly

An unexplained >4σ discrepancy persists between "beam" and "bottle" measurements of the neutron lifetime. A new model proposed that conversions of neutrons n into mirror neutrons n^{'}, part of a dark mirror sector, can increase the apparent neutron lifetime by 1% via a small mass splitting Δm between n and n^{'} inside the 4.6 T magnetic field of the National Institute of Standards and Technology Beam Lifetime experiment. A search for neutron conversions in a 6.6 T magnetic field was performed at the Spallation Neutron Source which excludes this explanation for the neutron lifetime discrepancy.

Joint Determination of Reactor Antineutrino Spectra from ^{235}U and ^{239}Pu Fission by Daya Bay and PROSPECT

A joint determination of the reactor antineutrino spectra resulting from the fission of ^{235}U and ^{239}Pu has been carried out by the Daya Bay and PROSPECT Collaborations. This Letter reports the level of consistency of ^{235}U spectrum measurements from the two experiments and presents new results from a joint analysis of both data sets. The measurements are found to be consistent. The combined analysis reduces the degeneracy between the dominant ^{235}U and ^{239}Pu isotopes and improves the uncertainty of the ^{235}U spectral shape to about 3%. The ^{235}U and ^{239}Pu antineutrino energy spectra are unfolded from the jointly deconvolved reactor spectra using the Wiener-SVD unfolding method, providing a data-based reference for other reactor antineutrino experiments and other applications. This is the first measurement of the ^{235}U and ^{239}Pu spectra based on the combination of experiments at low- and highly enriched uranium reactors.

Joint Measurement of the ^{235}U Antineutrino Spectrum by PROSPECT and STEREO

The PROSPECT and STEREO collaborations present a combined measurement of the pure ^{235}U antineutrino spectrum, without site specific corrections or detector-dependent effects. The spectral measurements of the two highest precision experiments at research reactors are found to be compatible with χ^{2}/ndf=24.1/21, allowing a joint unfolding of the prompt energy measurements into antineutrino energy. This ν[over ¯]_{e} energy spectrum is provided to the community, and an excess of events relative to the Huber model is found in the 5-6 MeV region. When a Gaussian bump is fitted to the excess, the data-model χ^{2} value is improved, corresponding to a 2.4σ significance.

Technical capacities needed to implement the WHO's primary eye care package for Africa: results of a Delphi process

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 deliver them using Gericke's framework of technical feasibility. The panel comprised nine eyecare experts in primary eyecare in sub-Saharan Africa. In each round panel members used a 4-point Likert scale to indicate their level of agreement. Consensus was predefined as ≥70% agreement on each statement. For round 1, statements on technical complexity were identified through a literature search of primary eyecare in sub-Saharan Africa from January 1980 to April 2018. Statements for which consensus was achieved were included in round 2, and the technical capacities were agreed.

RESULTS

Technical complexity statements were classified into four broad categories: intervention characteristics, delivery characteristics, government capacity requirements and usage characteristics. 34 of the 38 (89%) statements on health promotion and 40 of the 43 (93%) statements on facility case management were considered necessary technical capacities for implementation.

CONCLUSION

This study establishes the technical capacities needed to implement the WHO Africa Office primary eye care package, which may be generalisable to countries in sub-Saharan Africa.

Nonfuel Antineutrino Contributions in the High Flux Isotope Reactor

Reactor neutrino experiments have seen major improvements in precision in recent years. With the experimental uncertainties becoming lower than those from theory, carefully considering all sources of ν ¯ e is important when making theoretical predictions. One source of ν ¯ e that is often neglected arises from the irradiation of the nonfuel materials in reactors. The ν ¯ e rates and energies from these sources vary widely based on the reactor type, configuration, and sampling stage during the reactor cycle and have to be carefully considered for each experiment independently. In this article, we present a formalism for selecting the possible ν ¯ e sources arising from the neutron captures on reactor and target materials. We apply this formalism to the High Flux Isotope Reactor (HFIR) at Oak Ridge National Laboratory, the ν ¯ e source for the the Precision Reactor Oscillation and Spectrum Measurement (PROSPECT) experiment. Overall, we observe that the nonfuel ν ¯ e contributions from HFIR to PROSPECT amount to 1% above the inverse beta decay threshold with a maximum contribution of 9% in the 1.8-2.0 MeV range. Nonfuel contributions can be particularly high for research reactors like HFIR because of the choice of structural and reflector material in addition to the intentional irradiation of target material for isotope production. We show that typical commercial pressurized water reactors fueled with low-enriched uranium will have significantly smaller nonfuel ν ¯ e contribution.

Accuracy of the smartphone-based nonmydriatic retinal camera in the detection of sight-threatening diabetic retinopathy

Purpose:

To evaluate the sensitivity and specificity of smartphone-based nonmydriatic (NM) retinal camera in the detection of diabetic retinopathy (DR) and sight-threatening DR (STDR) in a tertiary eye care facility.

Methods:

Patients with diabetes underwent retinal photography with a smartphone-based NM fundus camera before mydriasis and standard 7-field fundus photography with a desktop mydriatic fundus camera after mydriasis. DR was graded using the international clinical classification of diabetic retinopathy system by two retinal expert ophthalmologists masked to each other and to the patient's identity. The sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) to detect DR and STDR by NM retinal imaging were assessed.

Results:

245 people had gradable images in one or both eyes. DR and STDR were detected in 45.3% and 24.5%, respectively using NM camera, and in 57.6% and 28.6%, respectively using mydriatic camera. The sensitivity and specificity to detect any DR by NM camera was 75.2% (95% confidence interval (CI) 68.1–82.3) and 95.2% (95%CI 91.1–99.3). For STDR the values were 82.9% (95% CI 74.0–91.7) and 98.9% (95% CI 97.3–100), respectively. The PPV to detect any DR was 95.5% (95% CI 89.8–98.5) and NPV was 73.9% (95% CI 66.4–81.3); PPV for STDR detection was 96.7% (95% CI 92.1–100)) and NPV was 93.5% (95% CI 90.0–97.1).

Conclusion:

Smartphone-based NM retinal camera had fairly high sensitivity and specificity for detection of DR and STDR in this clinic-based study. Further studies are warranted in other settings.

Fifteen-year incidence rate and risk factors of pterygium in the Southern Indian state of Andhra Pradesh

PURPOSE

To report 15-year incidence rate and associated risk factors of pterygium among people aged 30 years and above at baseline in the rural clusters of longitudinal Andhra Pradesh Eye Disease Study (APEDS III).

METHODS

The baseline APEDS I included 7771 participants of which 6447 (83%) were traced and 5395 (83.7%) were re-examined in APEDS III. To estimate the incidence of pterygium, we selected participants who were 30 years and above at baseline (4188), of which 2976 were traced and 2627 (88.3%) were examined, and based on inclusion criteria, 2290 participants were included in the study. The incidence rate of pterygium was defined as the proportion of people free of pterygium at baseline who had developed the condition at 15-year follow-up (range 13-17 years). Univariate and multivariable analyses for risk factors were undertaken.

RESULTS

The sex-adjusted incidence rate of pterygium was 25.2 per 100 person-years (95% CI 24.8 to 25.7) which was significantly higher for men than women (26.3 per 100 person-years (95% CI 25.6 to 27.0) and 24.7 (95% CI 24.1 to 25.3) respectively). At the multivariable analysis, male gender (RR: 1.35, 95% CI 1.0 to 1.83), no formal education (RR: 2.46, 95% CI 1.22 to 4.93), outdoor occupation (RR: 1.47, 95% CI 1.14 to 1.9) and lower body mass index (BMI) (<18.5) (RR: 1.25, 95% CI 1.02 to 1.55) were associated with increased risk of pterygium.

CONCLUSIONS

The overall incidence rate of pterygium was high in this rural population, especially in men and those engaged in outdoor activities, lack of formal education and with lower BMI. It is likely that greater exposure to ultraviolet light is a major contributing factor, thus warranting preventive strategies.

Presentation, surgery and 1-year outcomes of childhood cataract surgery in Tanzania

Background

Recent reports have suggested a significant change in the causes of blindness in children in low-income countries cataract becoming the leading cause. We aimed to investigate the presentations and surgical outcomes in children with cataract operated at different ages in Tanzania.

Methods

We conducted a prospective study of 228 children aged ≤192 months at three tertiary centres, 177 with bilateral cataracts and prospectively followed them for 1-year postsurgery. We collected demographic, surgical, preoperative and postoperative clinical characteristics using the standard childhood cataract surgical assessment questionnaire. Families were encouraged to return for follow-up by phone with travel reimbursement where necessary.

Results

Preoperatively, 76% bilateral children were blind in the better eye. 86% of children were followed up at 1 year and 54% bilateral children achieved visual acuity of 0.48 logMAR or better in the better eye and 5% were blind. 33% of unilateral children achieved visual acuity of 0.48 logMAR or better and 17% were blind. Preoperative blindness (adjusted OR (AOR) 14.65; 95% CI 2.21 to 97.20), preoperative nystagmus/strabismus (AOR 9.22; 95% CI 2.66 to 31.97) and aphakia (AOR, 5.32; 95% CI 1.05 to 26.97) predicted poor visual outcome in bilateral cases. 9% of 342 refracted eyes had initial postoperative cylinder of 1.5 D or more, as did a similar proportion (11%) of 315 eyes refracted 1 year after surgery. Acute fibrinous uveitis occurred in 41 (12%) eyes.

Conclusion

Three-quarters of children were blind preoperatively whereas over half had good vision 1-year postoperatively. Preoperative blindness, nystagmus/strabismus and aphakia predicted poor visual outcome, suggesting that cataract density determines density of amblyopia.

Cataract Services are Leaving Widows Behind: Examples from National Cross-Sectional Surveys in Nigeria and Sri Lanka

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; n = 13,591) and Sri Lanka (2012–2014; n = 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.

Measurement of the Antineutrino Spectrum from ^{235}U Fission at HFIR with PROSPECT

This Letter reports the first measurement of the ^{235}U ν[over ¯]_{e} energy spectrum by PROSPECT, the Precision Reactor Oscillation and Spectrum experiment, operating 7.9 m from the 85  MW_{th} highly enriched uranium (HEU) High Flux Isotope Reactor. With a surface-based, segmented detector, PROSPECT has observed 31678±304(stat) ν[over ¯]_{e}-induced inverse beta decays, the largest sample from HEU fission to date, 99% of which are attributed to ^{235}U. Despite broad agreement, comparison of the Huber ^{235}U model to the measured spectrum produces a χ^{2}/ndf=51.4/31, driven primarily by deviations in two localized energy regions. The measured ^{235}U spectrum shape is consistent with a deviation relative to prediction equal in size to that observed at low-enriched uranium power reactors in the ν[over ¯]_{e} energy region of 5-7 MeV.

First Search for Short-Baseline Neutrino Oscillations at HFIR with PROSPECT

This Letter reports the first scientific results from the observation of antineutrinos emitted by fission products of ^{235}U at the High Flux Isotope Reactor. PROSPECT, the Precision Reactor Oscillation and Spectrum Experiment, consists of a segmented 4 ton ^{6}Li-doped liquid scintillator detector covering a baseline range of 7-9 m from the reactor and operating under less than 1 m water equivalent overburden. Data collected during 33 live days of reactor operation at a nominal power of 85 MW yield a detection of 25 461±283 (stat) inverse beta decays. Observation of reactor antineutrinos can be achieved in PROSPECT at 5σ statistical significance within 2 h of on-surface reactor-on data taking. A reactor model independent analysis of the inverse beta decay prompt energy spectrum as a function of baseline constrains significant portions of the previously allowed sterile neutrino oscillation parameter space at 95% confidence level and disfavors the best fit of the reactor antineutrino anomaly at 2.2σ confidence level.

Reducing Blindness from Retinopathy of Prematurity (ROP) in Argentina Through Collaboration, Advocacy and Policy Implementation

Retinopathy of prematurity (ROP) is a largely avoidable cause of blindness in children worldwide, requiring high-quality neonatal care, early detection and treatment. In middle-income countries throughout Latin America, Eastern Europe and South Asia, there has been a rise in ROP blindness due to a combination of increased survival of preterm infants, resource-scarce medical environments and lack of policies, training and human resources. However, Argentina is an example of country where rates of ROP blindness have declined and ROP programmes have been successfully and effectively embedded within the health and legal system. The purpose of this study is to describe the activities and stakeholders, including Ministry of Health (MoH) and UNICEF, involved in the process, from recognition of an epidemic of ROP blindness to the development of national guidelines, policies and legislation for control. Using a retrospective mixed methods case study design, data on rates of severe ROP was collected from 13 neonatal intensive care units from 1999 to 2012, and on the proportion of children blind from ROP in nine blind schools in seven provinces. Legislative document review, focus group discussions and key informant interviews were conducted with neonatologists, ophthalmologists, neonatal nurses, parents, MoH officials, clinical societies, legislators and UNICEF officials in seven provinces. Results are presented combining the stages heuristic policy framework and Shiffman including: agenda setting, policy formulation, implementation and evaluation. By 2012, ROP had declined as a cause of blindness in children in schools for the blind as had rates of severe ROP needing treatment in the NICUs visited. Multiple factors played a role in reducing blindness from ROP in Argentina and successfully coordinating its control including national advocacy, leadership, legislation and international collaboration. Lessons learned in Argentina can potentially be scaled to other LMICs in Latin America and beyond with further context-specific research.

Evidence for national universal eye health plans

Many low- and middle-income countries use national eye-care plans to guide efforts to strengthen eye-care services. The World Health Organization recognizes that evidence is essential to inform these plans. We assessed how evidence was incorporated in a sample of 28 national eye-care plans generated since the Universal eye health: a global action plan 2014-2019 was endorsed by the World Health Assembly in 2013. Most countries (26, 93%) cited estimates of the prevalence of blindness and 18 countries (64%) had set targets for the cataract surgical rate in their plan. Other evidence was rarely cited or used to set measurable targets. No country cited evidence from systematic reviews or solution-based research. This limited use of evidence reflects its low availability, but also highlights incomplete use of existing evidence. For example, despite sex-disaggregated data and cataract surgical coverage being available from surveys in 20 countries (71%), these data were reported in the eye health plans of only nine countries (32%). Only three countries established sex-disaggregated indicators and only one country had set a target for cataract surgical coverage for future monitoring. Countries almost universally recognized the need to strengthen health information systems and almost one-third planned to undertake operational or intervention research. Realistic strategies need to be identified and supported to translate these intentions into action. To gain insights into how a country can strengthen its evidence-informed approach to eye-care planning, we reflect on the process underway to develop Kenya's seventh national plan (2019-2023).

Glaucoma-associated long-term mortality in a rural cohort from India: the Andhra Pradesh Eye Disease Study

Aim

To evaluate glaucoma-associated mortality in a rural cohort in India.

Methods

The study cohort comprised individuals aged 40 years and above who took part in the Andhra Pradesh Eye Disease Study (APEDS1) during 1996–2000. All participants underwent detailed comprehensive eye examination. Glaucoma was defined using International Society of Geographic and Epidemiologic Ophthalmology criteria. This cohort was followed up after a decade (June 2009 to January 2010; APEDS2). Mortality HR analysis for ocular risk factors was performed using Cox proportional hazards regression after adjusting for sociodemographic, lifestyle and clinical variables.

Results

In APEDS1, 2790 individuals aged more than or equal to 40 years were examined. 47.4% were male. Forty-five participants had primary open angle glaucoma (POAG) and 66 had primary angle closure disease (PACD). Ten years later, 1879 (67.3%) were available, 739 (26.5%) had died and 172 (6.2%) had migrated; whereas 22 of the 45 (48.8%) with POAG and 22 of the 66 (33.3%) with PACD had died. In univariate analysis, a higher mortality was associated with POAG (HR 1.9; 95% CI 1.23 to 2.94), pseudoexfoliation (HR 2.79; 95% CI 2.0 to 3.89), myopia (HR 1.78; 95% CI 1.54 to 2.06) and unit increase in cup:disc ratio (HR 4.49; 95% CI 2.64 to 7.64). In multivariable analysis, only cup:disc ratio remained independently associated with mortality (HR 2.5; 95% CI 1.3 to 5.1). The association remained significant when other ocular parameters were included in the model (HR 2.1; 95% CI 1.03 to 4.2).

Conclusions

This is the first longitudinal study to assess the association of glaucoma and mortality in a rural longitudinal cohort in India. Increased cup:disc ratio could be a potential marker for ageing and would need further validation.

Assessment of Response Bias Is Neglected in Cross-Sectional Blindness Prevalence Surveys: A Review of Recent Surveys in Low- and Middle-Income Countries

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.

Reducing inequity of cataract blindness and vision impairment is a global priority, but where is the evidence?

Throughout the world, people who are socially or economically disadvantaged disproportionately experience blindness and vision impairment caused by cataract. Reducing vision loss from cataract and its unequal distribution must be a priority if the WHO's aim of 'universal eye health' is to be realised. To help achieve this, decision-makers and service planners need evidence on which strategies improve access to cataract services among disadvantaged populations, and under what circumstances. Unfortunately, despite many strategies to improve cataract services being implemented in recent decades, evidence of what works, for who and in what circumstances is not readily available. This paper summarises the extent of the evidence on interventions to reduce inequity of vision loss from cataract and makes suggestions for how the evidence base can be strengthened.

Outcome of paediatric cataract surgery in Northwest Ethiopia: a retrospective case series

AIM

To assess visual acuity outcomes, and factors associated with the outcome, of paediatric cataract surgery at the Child Eye Health Tertiary Facility, Gondar, Northwest Ethiopia.

METHODS

The medical records of children aged below 16 years who underwent cataract surgery between September 2010 and August 2014 were reviewed for preoperative, surgical and postoperative data.

RESULTS

One hundred and seventy-six eyes of 142 children (mean age 7.9 years±4.2 SD, 66% male) who had cataract surgery were included. Twenty-five per cent (35/142) of children had bilateral cataract, 18 (13%) had unilateral non-traumatic cataracts and 89 (63%) had unilateral traumatic cataracts. An intraocular lens was implanted in 93% of eyes. Visual acuities at last follow-up: bilateral cases in the better eye: good (≥6/18 or fix and follow) in 21/34 eyes (62%), borderline (<6/18-6/60) in 4 eyes (12%) and poor (<6/60) in 9 eyes (26%). In unilateral non-traumatic cases: good in 6 eyes (33%), borderline in 3 eyes (17%) and poor in 9 eyes (50%). In unilateral traumatic cases: good in 36 eyes (40%), borderline in 20 eyes (23%) and poor in 33 eyes (37%). In bilateral cataract, worse outcomes were associated with preoperative nystagmus/strabismus. In traumatic cases, worse outcomes were associated with the preoperative trauma-related complications.

CONCLUSIONS

Visual acuity improved significantly after surgery, with better outcomes in bilateral cases. Early detection and surgery by a trained surgeon with good follow-up and postoperative rehabilitation can lead to better visual outcomes.

Willingness to pay for cataract surgery is much lower than actual costs in Zamfara state, northern Nigeria

PURPOSE

Direct medical and non-medical costs incurred by those undergoing subsidised cataract surgery at Gusau eye clinic, Zamfara state, were recently determined. The aim of this study was to assess the willingness to pay for cataract surgery among adults with severe visual impairment or blindness from cataract in rural Zamfara and to compare this to actual costs.

METHODS

In three rural villages served by Gusau eye clinic, key informants helped identify 80 adults with bilateral severe visual impairment or blindness (<6/60), with cataract being the cause in at least one eye. The median amount participants were willing to pay for cataract surgery was determined. The proportion willing to pay actual costs of the (i) subsidised surgical fee (US$18.5), (ii) average non-medical expenses (US$25.2), and (iii) average total expenses (US$51.2) at Gusau eye clinic were calculated. Where participants would seek funds for surgery was determined.

RESULTS

Among 80 participants (38% women), most (n = 73, 91%) were willing to pay something, ranging from <US$1 to US$186 (median US$18.5, interquartile range 6.2-31.1). Approximately half of the participants (n = 41) were willing to pay US$18.5 (78% men), one-third (n = 26) were willing to pay US$25.2 (77% men); and 11% (n = 9) were willing to pay US$51.2 (all men). Only six participants (8%) already had the money to pay; one quarter (n = 20) would need to sell possessions to raise the funds.

CONCLUSION

Willingness to pay for cataract surgery among adults with operable cataract in rural Zamfara state is far lower than current costs of undergoing surgery. People who were widowed-most of whom were women-were willing to pay least. Further financial support is required for cataract surgery to be universally accessible.

Avoidable Waste in Ophthalmic Epidemiology: A Review of Blindness Prevalence Surveys in Low and Middle Income Countries 2000-2014

PURPOSE

Sources of avoidable waste in ophthalmic epidemiology include duplication of effort, and survey reports remaining unpublished, gaining publication after a long delay, or being incomplete or of poor quality. The aim of this review was to assess these sources of avoidable waste by examining blindness prevalence surveys undertaken in low and middle income countries (LMICs) between 2000 and 2014.

METHODS

On December 1, 2016 we searched MEDLINE, EMBASE and Web of Science databases for cross-sectional blindness prevalence surveys undertaken in LMICs between 2000 and 2014. All surveys listed on the Rapid Assessment of Avoidable Blindness (RAAB) Repository website ("the Repository") were also considered. For each survey we assessed (1) availability of scientific publication, survey report, summary results tables and/or datasets; (2) time to publication from year of survey completion and journal attributes; (3) extent of blindness information reported; and (4) rigour when information was available from two sources (i.e. whether it matched).

RESULTS

Of the 279 included surveys (from 68 countries) 186 (67%) used RAAB methodology; 146 (52%) were published in a scientific journal, 57 (20%) were published in a journal and on the Repository, and 76 (27%) were on the Repository only (8% had tables; 19% had no information available beyond registration). Datasets were available for 50 RAABs (18% of included surveys). Time to publication ranged from <1 to 11 years (mean, standard deviation 2.8 ± 1.8 years). The extent of blindness information reported within studies varied (e.g. presenting and best-corrected, unilateral and bilateral); those with both a published report and Repository tables were most complete. For surveys published and with RAAB tables available, discrepancies were found in reporting of participant numbers (14% of studies) and blindness prevalence (15%).

CONCLUSION

Strategies are needed to improve the availability, consistency, and quality of information reported from blindness prevalence surveys, and hence reduce avoidable waste.

A worldwide survey of retinopathy of prematurity screening

BACKGROUND

To ascertain which countries in the world have retinopathy of prematurity (ROP) screening programmes and guidelines and how these were developed.

METHODS

An email database was created and requests were sent to ophthalmologists in 141 nations to complete an online survey on ROP screening in their country.

RESULTS

Representatives from 92/141 (65%) countries responded. 78/92 (85%) have existing ROP screening programmes, and 68/78 (88%) have defined screening criteria. Some countries have limited screening and those areas which have no screening or for which there is inadequate knowledge are mainly Southeast Asia, Africa and some former Soviet states.

DISCUSSION

With the increasing survival of premature babies in lower-middle-income and low-income countries, it is important to ensure that adequate ROP screening and treatment is in place. This information will help organisations focus their resources on those areas most in need.

Using the STROBE statement to assess reporting in blindness prevalence surveys in low and middle income countries

Objective

Cross-sectional blindness prevalence surveys are essential to plan and monitor eye care services. Incomplete or inaccurate reporting can prevent effective translation of research findings. The Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) statement is a 32 item checklist developed to improve reporting of observational studies. The aim of this study was to assess the completeness of reporting in blindness prevalence surveys in low and middle income countries (LMICs) using STROBE.

Methods

MEDLINE, EMBASE and Web of Science databases were searched on April 8 2016 to identify cross-sectional blindness prevalence surveys undertaken in LMICs and published after STROBE was published in December 2007. The STROBE tool was applied to all included studies, and each STROBE item was categorized as ‘yes’ (met criteria), ‘no’ (did not meet criteria) or ‘not applicable’. The ‘Completeness of reporting (COR) score’ for each manuscript was calculated: COR score = yes / [yes + no]. In journals with included studies the instructions to authors and reviewers were checked for reference to STROBE.

Results

The 89 included studies were undertaken in 32 countries and published in 37 journals. The mean COR score was 60.9% (95% confidence interval [CI] 58.1–63.7%; range 30.8–88.9%). The mean COR score did not differ between surveys published in journals with author instructions referring to STROBE (10/37 journals; 61.1%, 95%CI 56.4–65.8%) or in journals where STROBE was not mentioned (60.9%, 95%CI 57.4–64.3%; p = 0.93).

Conclusion

While reporting in blindness prevalence surveys is strong in some areas, others need improvement. We recommend that more journals adopt the STROBE checklist and ensure it is used by authors and reviewers.

Effective cataract surgical coverage: An indicator for measuring quality-of-care in the context of Universal Health Coverage

OBJECTIVE

To define and demonstrate effective cataract surgical coverage (eCSC), a candidate UHC indicator that combines a coverage measure (cataract surgical coverage, CSC) with quality (post-operative visual outcome).

METHODS

All Rapid Assessment of Avoidable Blindness (RAAB) surveys with datasets on the online RAAB Repository on April 1 2016 were downloaded. The most recent study from each country was included. By country, cataract surgical outcome (CSOGood, 6/18 or better; CSOPoor, worse than 6/60), CSC (operated cataract as a proportion of operable plus operated cataract) and eCSC (operated cataract and a good outcome as a proportion of operable plus operated cataract) were calculated. The association between CSC and CSO was assessed by linear regression. Gender inequality in CSC and eCSC was calculated.

FINDINGS

Datasets from 20 countries were included (2005-2013; 67,337 participants; 5,474 cataract surgeries). Median CSC was 53.7% (inter-quartile range[IQR] 46.1-66.6%), CSOGood was 58.9% (IQR 53.7-67.6%) and CSOPoor was 17.7% (IQR 11.3-21.1%). Coverage and quality of cataract surgery were moderately associated-every 1% CSC increase was associated with a 0.46% CSOGood increase and 0.28% CSOPoor decrease. Median eCSC was 36.7% (IQR 30.2-50.6%), approximately one-third lower than the median CSC. Women tended to fare worse than men, and gender inequality was slightly higher for eCSC (4.6% IQR 0.5-7.1%) than for CSC (median 2.3% IQR -1.5-11.6%).

CONCLUSION

eCSC allows monitoring of quality in conjunction with coverage of cataract surgery. In the surveys analysed, on average 36.7% of people who could benefit from cataract surgery had undergone surgery and obtained a good visual outcome.

Inequality in cataract blindness and services: moving beyond unidimensional analyses of social position

OBJECTIVE

Inequalities in cataract blindness are well known, but data are rarely disaggregated to explore the combined effects of a range of axes describing social disadvantage. We examined inequalities in cataract blindness and services at the intersection of three social axes.

METHODS

Three dichotomous social variables (sex (male/female); place of residence (urban/rural); literacy (literate/illiterate)) from cross-sectional national blindness surveys in Pakistan (2001-2004; n=16 507) and Nigeria (2005-2007; n=13 591) were used to construct eight subgroups, with disadvantaged subgroups selected a priori (ie, women, rural dwellers, illiterate). In each data set, the social distribution of cataract blindness, cataract surgical coverage (CSC) and effective cataract surgical coverage (eCSC) were examined. Inequalities were assessed comparing the best-off and worst-off subgroups using rate differences and rate ratios (RRs). Logistic regression was used to assess cumulative effects of multiple disadvantage.

RESULTS

Disadvantaged subgroups experienced higher prevalence of cataract blindness, lower CSC and lower eCSC in both countries. A social gradient was present for CSC and eCSC, with coverage increasing as social position improved. Relative inequality in eCSC was approximately twice as high as CSC (Pakistan: eCSC RR 2.7 vs CSC RR 1.3; Nigeria: eCSC RR 8.7 vs CSC RR 4.1). Cumulative disadvantage was observed for all outcomes, deteriorating further with each additional axis along which disadvantage was experienced.

CONCLUSIONS

Each outcome tended to be worse with the addition of each layer of social disadvantage. Illiterate, rural women fared worst in both settings. Moving beyond unidimensional analyses of social position identified subgroups in most need; this permits a more nuanced response to addressing the inequitable distribution of cataract blindness.

Poverty and blindness in Nigeria

No abstract available.

So let me find my way, whatever it will cost me, rather than leaving myself in darkness: experiences of glaucoma in Nigeria

BACKGROUND

Blindness from glaucoma is associated with socio-economic deprivation, presumed to reflect poor access to care and poor adherence to treatment.

OBJECTIVES

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.

DESIGN

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.

RESULTS

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.

CONCLUSION

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.

Case series of infants presenting with end stage retinopathy of prematurity to two tertiary eye care facilities in Mexico: underlying reasons for late presentation

To describe the characteristics of infants with bilateral Stage 4b or 5 ROP (i.e. with subtotal or total retinal detachment) who presented to eye departments in two major cities in Mexico, to identify reasons why they may have become blind in order to recommend how programs could be improved. A large case-series of infants with Stage 4b or 5 ROP in both eyes confirmed by ultrasound who attended the ROP Clinic, Hospital Civil de Guadalajara from September 2010 to November 2012, and the Department of Ophthalmology, Hospital Infantil de Mexico Federico Gomez from December 2011 to December 2012 were identified from the diagnostic databases of each hospital. Mothers of infants in Guadalajara had a telephone interview. 89/94 eligible infants were included in the study, 48 in Guadalajara and 41 in Mexico City. Cases came from 22 of the 32 states in Mexico. Half of the infants attending Guadalajara 24/48 (50 %) had been cared for in NICUs without ROP screening programs and were not examined. Among the 24 infants cared for in NICUs with ROP programs, 7/24 (29.1 %) mothers reported that their infant had not been examined while in the NICU, and a further 9/24 (37.5 %) were either not referred for screening after discharge or they did not attend. Two infants had failed laser treatment. Strategies and resources to prevent end stage ROP have not been firmly established in Mexico. There is an urgent need to expand the coverage and quality of ROP programs, to ensure that existing screening guidelines are better adhered to, and to improve communication with parents.

Poverty and Blindness in Nigeria: Results from the National Survey of Blindness and Visual Impairment

PURPOSE

Poverty can be a cause and consequence of blindness. Some causes only affect the poorest communities (e.g. trachoma), and poor individuals are less likely to access services. In low income countries, cataract blind adults have been shown to be less economically active, indicating that blindness can exacerbate poverty. This study aims to explore associations between poverty and blindness using national survey data from Nigeria.

METHODS

Participants ≥40 years were examined in 305 clusters (2005-2007). Sociodemographic information, including literacy and occupation, was obtained by interview. Presenting visual acuity (PVA) was assessed using a reduced tumbling E LogMAR chart. Full ocular examination was undertaken by experienced ophthalmologists on all with PVA <6/12 in either eye. Causes of vision loss were determined using World Health Organization guidelines. Households were categorized into three levels of poverty based on literacy and occupation at household level.

RESULTS

A total of 569/13,591 participants were blind (PVA <3/60, better eye; prevalence 4.2%, 95% confidence interval [CI] 3.8-4.6%). Prevalences of blindness were 8.5% (95% CI 7.7-9.5%), 2.5% (95% CI 2.0-3.1%), and 1.5% (95% CI 1.2-2.0%) in poorest, medium and affluent households, respectively (p = 0.001). Cause-specific prevalences of blindness from cataract, glaucoma, uncorrected aphakia and corneal opacities were significantly higher in poorer households. Cataract surgical coverage was low (37.2%), being lowest in females in poor households (25.3%). Spectacle coverage was 3 times lower in poor than affluent households (2.4% vs. 7.5%).

CONCLUSION

In Nigeria, blindness is associated with poverty, in part reflecting lower access to services. Reducing avoidable causes will not be achieved unless access to services improves, particularly for the poor and women.

Is India's policy framework geared for effective action on avoidable blindness from diabetes?

BACKGROUND

The growing burden of avoidable blindness caused by diabetic retinopathy (DR) needs an effective and holistic policy that reflects mechanisms for early detection and treatment of DR to reduce the risk of blindness.

MATERIALS AND METHODS

We performed a comprehensive health policy review to highlight the existing systemic issues that enable policy translation and to assess whether India's policy architecture is geared to address the mounting challenge of DR. We used a keyword-based Internet search for documents available in the last 15 years. Two reviewers independently assessed retrieved policies and extracted contextual and program-oriented information and components delineated in national policy documents. Using a "descriptive analytical" method, the results were collated and summarized as per themes to present status quo, gaps, and recommendations for the future.

RESULTS

Lack of focus on building sustainable synergies that require well laid out mechanisms for collaboration within and outside the health sector and poor convergence between national health programs appears to be the weakest links across policy documents.

CONCLUSIONS

To reasonably address the issues of consistency, comprehensiveness, clarity, context, connectedness, and sustainability, policies will have to rely more strongly on evidence from operational research to support decisions. There is a need to involve multiple stakeholders from multiple sectors, recognize contributions from not-for-profit sector and private health service providers, and finally bring about a nuanced holistic perspective that has a voice with implementable multiple sector actions.

Estimating the proportion of persons with diabetes developing diabetic retinopathy in India: A systematic review and meta-analysis

BACKGROUND

Available evidence from India shows that the control of diabetes is poor in majority of the population. This escalates the risk of complications. There is no systematic review to estimate the magnitude of diabetic retinopathy (DR) in India.

MATERIALS AND METHODS

A systematic literature search was carried out in Ovid Medline and EMBASE databases using Mesh and key search terms. Studies which reported the proportion of people with diabetes with DR in a representative community population were included. Two independent reviewers reviewed all the retrieved publications. Data were extracted using a predefined form. Review Manager software was used to perform meta-analysis to provide a pooled estimate. Studies included were assessed for methodological quality using selected items from the STROBE checklist.

RESULTS

Seven studies (1999-2014; n = 8315 persons with diabetes) were included in the review. In the meta-analysis, 14.9% (95% confidence interval [CI] 10.7-19.0%) of known diabetics aged ≥30 years and 18.1% (95% CI 14.8-21.4) among those aged ≥50 years had DR. Heterogeneity around this estimate ranged from I(2)= 79-87%. No linear trend was observed between age and the proportion with DR. The overall methodological quality of included studies was moderate.

CONCLUSIONS

Early detection of DR is currently not prioritized in public health policies for noncommunicable diseases and blindness programs. Methodological issues in studies suggest that the proportion of diabetics with DR is underestimated in the Indian population. Future research should emphasize more robust methodology for assessing diabetes and DR status.

Perceptions and practices related to diabetes reported by persons with diabetes attending diabetic care clinics: The India 11-city 9-state study

BACKGROUND

India has the second largest population of persons with diabetes and a significant proportion has poor glycemic control and inadequate awareness of management of diabetes.

OBJECTIVES

Determine the level of awareness regarding management of diabetes and its complications and diabetic care practices in India.

METHODS

The cross-sectional, hospital-based survey was conducted in 11 cities where public and private providers of diabetic care were identified. At each diabetic care facility, 4-6 persons with diabetes were administered a structured questionnaire in the local language.

RESULTS

Two hundred and eighty-five persons with diabetes were interviewed. The mean duration since diagnosis of diabetes was 8.1 years (standard deviation ± 7.3). Half of the participants reported a family history of diabetes and 41.7% were hypertensive. Almost 62.1% stated that they received information on diabetes and its management through interpersonal channels. Family history (36.1%), increasing age (25.3%), and stress (22.8%) were the commonest causes of diabetes reported. Only 29.1% stated that they monitored their blood sugar levels at home using a glucometer. The commonest challenges reported in managing diabetes were dietary modifications (67.4%), compliance with medicines (20.5%), and cost of medicines (17.9%). Around 76.5% were aware of complications of diabetes. Kidney failure (79.8%), blindness/vision loss (79.3%), and heart attack (56.4%) were the commonest complications mentioned. Almost 67.7% of the respondents stated that they had had an eye examination earlier.

CONCLUSIONS

The findings have significant implications for the organization of diabetes services in India for early detection and management of complications, including eye complications.

Eye care infrastructure and human resources for managing diabetic retinopathy in India: The India 11-city 9-state study

BACKGROUND

There is a paucity of information on the availability of services for diagnosis and management of diabetic retinopathy (DR) in India.

OBJECTIVES

The study was undertaken to document existing healthcare infrastructure and practice patterns for managing DR.

METHODS

This cross-sectional study was conducted in 11 cities and included public and private eye care providers. Both multispecialty and stand-alone eye care facilities were included. Information was collected on the processes used in all steps of the program, from how diabetics were identified for screening through to policies about follow-up after treatment by administering a semistructured questionnaire and by using observational checklists.

RESULTS

A total of 86 eye units were included (31.4% multispecialty hospitals; 68.6% stand-alone clinics). The availability of a dedicated retina unit was reported by 68.6% (59) facilities. The mean number of outpatient consultations per year was 45,909 per responding facility, with nearly half being new registrations. A mean of 631 persons with sight-threatening-DR (ST-DR) were registered per year per facility. The commonest treatment for ST-DR was laser photocoagulation. Only 58% of the facilities reported having a full-time retina specialist on their rolls. More than half the eye care facilities (47; 54.6%) reported that their ophthalmologists would like further training in retina. Half (51.6%) of the facilities stated that they needed laser or surgical equipment. About 46.5% of the hospitals had a system to track patients needing treatment or for follow-up.

CONCLUSIONS

The study highlighted existing gaps in service provision at eye care facilities in India.

Situational analysis of services for diabetes and diabetic retinopathy and evaluation of programs for the detection and treatment of diabetic retinopathy in India: Methods for the India 11-city 9-state study

BACKGROUND

Diabetic retinopathy (DR) is a leading cause of visual impairment in India. Available evidence shows that there are more than 60 million persons with diabetes in India and that the number will increase to more than a 100 million by 2030. There is a paucity of data on the perceptions and practices of persons with diabetes and the available infrastructure and uptake of services for DR in India.

OBJECTIVES

Assess perception of care and challenges faced in availing eye care services among persons with diabetics and generate evidence on available human resources, infrastructure, and service utilization for DR in India.

METHODS

The cross-sectional, hospital-based survey was conducted in eleven cities across 9 States in India. In each city, public and private providers of eye-care were identified. Both multispecialty and standalone facilities were included. Specially designed semi-open ended questionnaires were administered to the clients. Semi-structured interviews were administered to the service providers (both diabetic care physicians and eye care teams) and observational checklists were used to record findings of the assessment of facilities conducted by a dedicated team of research staff.

RESULTS

A total of 859 units were included in this study. This included 86 eye care and 73 diabetic care facilities, 376 persons with diabetes interviewed in the eye clinics and 288 persons with diabetes interviewed in the diabetic care facilities.

CONCLUSIONS

The findings will have significant implications for the organization of services for persons with diabetes in India.

Strengthening diabetes retinopathy services in India: Qualitative insights into providers' perspectives: The India 11-city 9-state study

CONTEXT

There is a lack of evidence on the subjective aspects of the provider perspective regarding diabetes and its complications in India.

OBJECTIVES

The study was undertaken to understand the providers' perspective on the delivery of health services for diabetes and its complications, specifically the eye complications in India.

SETTINGS AND DESIGN

Hospitals providing diabetic services in government and private sectors were selected in 11 of the largest cities in India, based on geographical distribution and size.

METHODS

Fifty-nine semi-structured interviews conducted with physicians providing diabetes care were analyzed all interviews were recorded, transcribed, and translated. Nvivo 10 software was used to code the transcripts. Thematic analysis was conducted to analyze the data.

RESULTS

The results are presented as key themes: "Challenges in managing diabetes patients," "Current patient management practices," and "Strengthening diabetic retinopathy (DR) services at the health systems level." Diabetes affects people early across the social classes. Self-management was identified as an important prerequisite in controlling diabetes and its complications. Awareness level of hospital staff on DR was low. Advances in medical technology have an important role in effective management of DR. A team approach is required to provide comprehensive diabetic care.

CONCLUSIONS

Sight-threatening DR is an impending public health challenge that needs a concerted effort to tackle it. A streamlined, multi-dimensional approach where all the stakeholders cooperate is important to strengthening services dealing with DR in the existing health care setup.

Human resources, patient load, and infrastructure at institutions providing diabetic care in India: The India 11-city 9-state study

BACKGROUND

There is a lack of information on the practice patterns and available human resources and services for screening for eye complications among persons with diabetes in India.

OBJECTIVES

The study was undertaken to document existing health care infrastructure and practice patterns for managing diabetes and screening for eye complications.

METHODS

This cross-sectional, hospital-based survey was conducted in 11 cities where public and private diabetic care providers were identified. Both multispecialty and standalone diabetic care facilities were included. A semi-structured questionnaire was administered to senior representative(s) of each institution to evaluate parameters using the World Health Organization health systems framework.

RESULTS

We interviewed physicians in 73 hospitals (61.6% multispecialty hospitals; 38.4% standalone clinics). Less than a third reported having skilled personnel for direct ophthalmoscopy. About 74% had provision for glycated hemoglobin testing. Only a third had adequate vision charts. Printed protocols on management of diabetes were available only in 31.5% of the facilities. Only one in four facilities had a system for tracking diabetics. Half the facilities reported having access to records from the treating ophthalmologists. Direct observation of the services provided showed that reported figures in relation to availability of patient support services were overestimated by around 10%. Three fourths of the information sheets and half the glycemia monitoring cards contained information on the eye complications and the need for a regular eye examination.

CONCLUSIONS

The study highlighted existing gaps in service provision at diabetic care centers in India.

Perception of care and barriers to treatment in individuals with diabetic retinopathy in India: 11-city 9-state study

BACKGROUND

Diabetic retinopathy is a leading cause of visual impairment. Low awareness about the disease and inequitable distribution of care are major challenges in India.

OBJECTIVES

Assess perception of care and challenges faced in availing care among diabetics.

MATERIALS AND METHODS

The cross-sectional, hospital based survey was conducted in eleven cities. In each city, public and private providers of eye-care were identified. Both multispecialty and standalone facilities were included. Specially designed semi-open ended questionnaires were administered to the clients.

RESULTS

376 diabetics were interviewed in the eye clinics, of whom 62.8% (236) were selected from facilities in cities with a population of 7 million or more. The mean duration of known diabetes was 11.1 (±7.7) years. Half the respondents understood the meaning of adequate glycemic control and 45% reported that they had visual loss when they first presented to an eye facility. Facilities in smaller cities and those with higher educational status were found to be statistically significant predictors of self-reported good/adequate control of diabetes. The correct awareness of glycemic control was significantly high among attending privately-funded facilities and higher educational status. Self-monitoring of glycemic status at home was significantly associated with respondents from larger cities, privately-funded facilities, those who were better educated and reported longer duration of diabetes. Duration of diabetes (41%), poor glycemic control (39.4%) and age (20.7%) were identified as the leading causes of DR. The commonest challenges faced were lifestyle/behavior related.

CONCLUSIONS

The findings have significant implications for the organization of diabetes services in India.

Genetic and Dietary Factors Influencing the Progression of Nuclear Cataract

Purpose

To determine the heritability of nuclear cataract progression and to explore prospectively the effect of dietary micronutrients on the progression of nuclear cataract.

Design

Prospective cohort study.

Participants

Cross-sectional nuclear cataract and dietary measurements were available for 2054 white female twins from the TwinsUK cohort. Follow-up cataract measurements were available for 324 of the twins (151 monozygotic and 173 dizygotic twins).

Methods

Nuclear cataract was measured using a quantitative measure of nuclear density obtained from digital Scheimpflug images. Dietary data were available from EPIC food frequency questionnaires. Heritability was modeled using maximum likelihood structural equation twin modeling. Association between nuclear cataract change and micronutrients was investigated using linear and multinomial regression analysis. The mean interval between baseline and follow-up examination was 9.4 years.

Main Outcome Measures

Nuclear cataract progression.

Results

The best-fitting model estimated that the heritability of nuclear cataract progression was 35% (95% confidence interval [CI], 13–54), and individual environmental factors explained the remaining 65% (95% CI, 46–87) of variance. Dietary vitamin C was protective against both nuclear cataract at baseline and nuclear cataract progression (β = −0.0002, P = 0.01 and β = −0.001, P = 0.03, respectively), whereas manganese and intake of micronutrient supplements were protective against nuclear cataract at baseline only (β = −0.009, P = 0.03 and β = −0.03, P = 0.01, respectively).

Conclusions

Genetic factors explained 35% of the variation in progression of nuclear cataract over a 10-year period. Environmental factors accounted for the remaining variance, and in particular, dietary vitamin C protected against cataract progression assessed approximately 10 years after baseline.

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.