Risk factors for corneal ulcers: a population-based matched case-control study in Nepal - PubMed (original) (raw)
Randomized Controlled Trial
. 2023 Nov 22;107(12):1771-1775.
doi: 10.1136/bjo-2022-322141.
Ram Prasad Kandel # 1 2, Bimal Poudyal 1, Sadhan Bhandari 1, Anju Ligal 1, Sangita Pradhan 1, Maria Gautam 1, Puspa Shrestha 1, Ranjeet Kumar Sah 1, John A Gonzales 3 4, Travis C Porco 3 5, John P Whitcher 3, Muthiah Srinivasan 6, Madan Prasad Upadhyay 7, Thomas M Lietman 3 4 5 8, Jeremy David Keenan 3 4, Kieran S O'Brien 9 4 5 8; Village-Integrated Eye Worker Trial Group
Collaborators, Affiliations
- PMID: 36202599
- PMCID: PMC10076439
- DOI: 10.1136/bjo-2022-322141
Randomized Controlled Trial
Risk factors for corneal ulcers: a population-based matched case-control study in Nepal
Raghunandan Byanju et al. Br J Ophthalmol. 2023.
Abstract
Background/aims: We aimed to examine risk factors for corneal ulcer in a rural and peri-urban setting in Nepal.
Methods: This population-based matched case-control study was nested in a cluster randomised trial in 24 village development committees in Nepal. Incidence density sampling was used to match incident corneal opacity cases to controls, matching on time of opacity, age, sex and location. Cases and controls were invited to participate in a survey of risk factors for corneal ulcer. Risk factors were evaluated using conditional logistic regression to account for matching.
Results: Of the 540 participants with incident opacities identified in the trial, 433 were willing to participate in this substudy and matched to a control. Compared with controls, cases had lower odds of having any education vs no education (adjusted OR, aOR 0.60, 95% CI 0.39 to 0.94), working in non-manual labour occupations vs manual labour occupations (aOR 0.64, 95% CI 0.42 to 0.95) and preferring medical shops for ocular trauma versus eye care system centres (aOR 0.58, 95% CI 0.37 to 0.92). Cases had higher odds of protective goggle use versus no protection (aOR 3.8, 95% CI 1.3 to 11.0) and having an ocular injury vs none (aOR 7.7, 95% CI 4.3 to 13.6) compared with controls.
Conclusion: We found ocular injury, manual labour and lower education to be strongly associated with the development of corneal ulcer. Given the persistent burden of corneal blindness in this area, prevention efforts could target efforts to increase access to care in areas where these factors are common.
Keywords: cornea; epidemiology; public health.
© Author(s) (or their employer(s)) 2023. No commercial re-use. See rights and permissions. Published by BMJ.
Conflict of interest statement
Competing interests: None declared.
Figures
Figure 1.
Eligible cases were participants with incident corneal ulcers identified from corneal photographs taken during the main trial. Cases were contacted by phone or in-person visits up to 3 times to complete a study visit for the case-control study. Controls were matched to cases on age (± 2 years), sex, and ward of residence from among trial participants still at risk for corneal ulcer within the same census period as cases.
Figure 2.
Conditional logistic regression was used to estimate exposure odds ratios for each risk factor, accounting for the matching variables (age, sex, ward). Results are presented overall as well as by subgroups defined by population density.
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