Purchase this article with an account.
Shivaa Sarah-Ann Ramsewak, Neville Verlander, Frank Deomansingh, Amandi Fraser, Vedatta Maharaj, Subash Sharma, Deo Singh, Rupert Richard Bourne, Tasanee Braithwaite; National Eye Survey of Trinidad and Tobago: the prevalence and risk factors for refractive error. Invest. Ophthalmol. Vis. Sci. 2016;57(12):3976.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
This study estimated the prevalence of refractive error, and associated risk factors, in people aged 40 years and over in Trinidad and Tobago, a Caribbean nation with a population of 1.3 million.
A population-based, nationally-representative, cross-sectional survey, using randomized multistage cluster sampling with probability proportionate to size methods, identified 120 clusters each of 35 people. Refractive error was determined by autorefraction (Topcon KR8000-PA). The prevalence of refractive errors amongst participants who were phakic was analysed for the right eye only. Myopia was defined as a spherical equivalent refraction (SE) less than -0.50 dioptres (D), hypermetropia as a SE greater than 0.50 D, astigmatism as a cylinder less than -0.50 D, and anisometropia as a difference in the right and left eye SE greater than 1.00 D.
Of 4200 people enumerated, 2334 (55.6%) attended clinic for a comprehensive optometric assessment. 161 people with previous cataract surgery in the right eye were excluded from the analysis. The mean age was 56.2 years (sd 10.0) and 56.9% were female. The median SE was 0.50 D in the right eye (IQR -0.38 to 1.25, range -23.40 to 14.50) and 0.50 D in the left eye (IQR -0.38 to 1.38, range -19.9 to 15.6), p= 0.34. The crude prevalence of myopia was 18.6% (95% CI, 17.0 to 20.2), of hypermetropia was 47.5% (95% CI 45.4 to 49.6), of astigmatism was 37.1% (95% CI 35.4 to 38.7), and of anisometropia was 12.0% (95% CI 10.7 to 13.5). After accounting for sampling design, using response-based weighting, and post-stratification based on age, sex, and municipality, the prevalence of myopia was 19.2% (95% CI 17.5 to 21.0) and of hypermetropia was 45.7% (95% CI 43.4 to 48.1). 37.5% currently owned spectacles for distance correction. In multilevel multivariable analysis risk factors for myopia included age (non linear), increasing years of education and African descent, whilst risk factors for hypermetropia included increasing age and South Asian descent.
Half of older adults in Trinidad and Tobago are hypermetropic and one fifth are myopic, and less than forty percent own spectacles. Uncorrected refractive error is a leading cause of avoidable vision impairment globally. These findings contribute to our understanding of the burden and risk factors for refractive error in the Caribbean region.
This is an abstract that was submitted for the 2016 ARVO Annual Meeting, held in Seattle, Wash., May 1-5, 2016.
This PDF is available to Subscribers Only