Anglia Ruskin University
Braithwaite_et_al_2017.pdf (1.64 MB)

The National Eye Survey of Trinidad and Tobago (NESTT): Rationale, objectives and methodology

Download (1.64 MB)
journal contribution
posted on 2023-07-26, 14:03 authored by Tasanee Braithwaite, Neville Q. Verlander, Debra Bartholomew, Petra Bridgemohan, Kevin McNally, Allana Roach, Subash Sharma, Deo Singh, Konrad Pesudovs, Surujpal Teelucksingh, Christine Carrington, Samuel Ramsewak, Rupert R. A. Bourne
Purpose: This paper describes the rationale, study design and procedures of the National Eye Survey of Trinidad and Tobago (NESTT). The main objective of this survey is to obtain prevalence estimates of vision impairment and blindness for planning and policy development. Methods: A population-based, cross-sectional survey was undertaken using random multistage cluster sampling, with probability-proportionate-to-size methods. Eligible participants aged 5 years and older were sampled from the non-institutional population in each of 120 cluster segments. Presenting distance and near visual acuity were screened in their communities. People aged 40 years and older, and selected younger people, were invited for comprehensive clinic assessment. The interview included information on potential risk factors for vision loss, associated costs and quality of life. The examination included measurement of anthropometrics, blood glucose, refraction, ocular biometry, corneal hysteresis, and detailed assessment of the anterior and posterior segments, with photography and optical coherence tomography imaging. Adult participants were invited to donate saliva samples for DNA extraction and storage. Results: The fieldwork was conducted over 13 months in 2013–2014. A representative sample of 10,651 individuals in 3410 households within 120 cluster segments identified 9913 people who were eligible for recruitment. Conclusion: The study methodology was robust and adequate to provide the first population-based estimates of the prevalence and causes of visual impairment and blindness in Trinidad and Tobago. Information was also gathered on risk factors, costs and quality of life associated with vision loss, and on normal ocular parameters for the population aged 40 years and older.



  • Yes



Issue number


Page range


Publication title

Ophthalmic Epidemiology




Taylor & Francis

File version

  • Published version


  • eng

Legacy posted date


Legacy creation date


Legacy Faculty/School/Department

ARCHIVED Faculty of Medical Science (until September 2018)

Usage metrics

    ARU Outputs


    No categories selected