Cluster-randomised trial of community-based screening for eye disease in adults in Nepal: the Village-Integrated Eye Worker Trial II (VIEW II) trial protocol

Abstract

IntroductionThe majority of blindness worldwide could be prevented or reversed with early diagnosis and treatment, yet identifying at-risk and prevalent cases of eye disease and linking them with care remain important obstacles to addressing this burden. Leading causes of blindness like glaucoma, diabetic retinopathy and age-related macular degeneration have detectable early asymptomatic phases and can cause irreversible vision loss. Mass screening for such diseases could reduce visual impairment at the population level.Methods and analysisThis protocol describes a parallel-group cluster-randomised trial designed to determine whether community-based screening for glaucoma, diabetic retinopathy and age-related macular degeneration reduces population-level visual impairment in Nepal. A door-to-door population census is conducted in all study communities. All adults aged ≥60 years have visual acuity tested at the census visit, and those meeting referral criteria are referred to a local eye care facility for further diagnosis and management. Communities are subsequently randomised to a community-based screening programme or to no additional intervention. The intervention consists of a single round of screening including intraocular pressure and optical coherence tomography assessment of all adults ≥60 years old with enhanced linkage to care for participants meeting referral criteria. Four years after implementation of the intervention, masked outcome assessors conduct a repeat census to collect data on the primary outcome, visual acuity. Individuals with incident visual impairment receive a comprehensive ophthalmological examination to determine the cause of visual impairment. Outcomes are compared by treatment arm according to the originally assigned intervention.Ethics and disseminationThe trial has received ethical approval from the University of California San Francisco Institutional Review Board, Nepal Netra Jyoti Sangh and the Nepal Health Research Council. Results of this trial will be disseminated through publication in peer-reviewed journals and presentation at local and international meetings.Trial registration numberNCT03752840

Relationship Between Intraocular Pressure and Age: A Population-Based Study in Nepal

“…It is possible that IOP was different among nonparticipants, although no evidence for this was found in a community-level analysis that plotted the mean age-stratified IOP versus the participation rate in the community. The study was done in the context of a large simple trial of eye disease screening 11 . In exchange for the large sample size, the study minimizes the number of data points collected.…”

“…The study was done in the context of a large simple trial of eye disease screening. 11 In exchange for the large sample size, the study minimizes the number of data points collected. Data were not collected on important biological factors, such as corneal biomechanical properties, that may have affected the IOP measurements, nor on the presence or severity of glaucoma.…”

“…The present study was conducted in a subset of communities enrolled in the Village Integrated Eye Worker Trial II, an ongoing NIH-funded cluster-randomized trial in Nepal that started on April 21, 2019 (clinicaltrials.gov NCT03752840). 11 Village Integrated Eye Worker Trial II takes place in periurban communities in the Chitwan and Nawalpur districts in Nepal that fall in the catchment area of Bharatpur Eye Hospital. In the trial, a door-to-door census is performed for all households in a contiguous DOI: 10.1097/IJG.0000000000002291 geographic area surrounding Bharatpur, Nepal.…”

“…And those studies that have been done have found conflicting results regarding the association between IOP and age. An ongoing cluster-randomized trial in Nepal that is enrolling participants from the general population provided an opportunity to provide more data relevant to the Indian subcontinent 11 . Here, we report the age-stratified IOP distribution from a population-based sample of adults in a periurban region of Nepal.…”

“…An ongoing cluster-randomized trial in Nepal that is enrolling participants from the general population provided an opportunity to provide more data relevant to the Indian subcontinent. 11 Here, we report the age-stratified IOP distribution from a population-based sample of adults in a periurban region of Nepal. The main objective of this report was to assess the relationship among IOPs across increasing age strata in a population-based sample of older adults from Nepal.…”