Sight Impairment registration in Trinidad: 35-year trend in causes and population coverage in comparison to the National Eye Survey of Trinidad and Tobago

Abstract Background: Little was known causes and coverage of sight impairment (SI) registration in the Caribbean. We compared the Trinidad and Tobago Blind Welfare Association (TTBWA) register and findings from the 2014 National Eye Survey of Trinidad and Tobago (NESTT). Methods: This study included TTBWA register analysis; cross-sectional validation studies of registered clients, involving interviews, vision function and cause ascertainment in July 2013, and interview and visual function measurement only in July 2016; comparison of causes of SI between register and national survey, and estimation of registration coverage. Results: The TTBWA register included 863 people (all ages) registered between 1980 and 2015, 48.1%(n=415) male. The NESTT identified 1.1%(75/7158) people aged >5years eligible for SI or SSI registration, 49.3%(n=37) male. The causes of SI and SSI agreed closely between the register and population-representative survey, with glaucoma being the leading cause in both the register (26.1%,n=225) and population survey (26.1%, 18/69 adults), followed by cataract and diabetic retinopathy. In the validation studies combined, 62.6%(93/151) clients had SSI, 28.5%(43/151) had (partial) SI and 9.9%(15/151) did not meet SI eligibility criteria. Registration coverage was approximately 7% of the eligible population in Trinidad. SI and SSI were potentially avoidable in at least 58%(n=36/62) adults and 50%(n=7/14) children examined in the 2013 validation study. Conclusion: We report close agreement in causes of SI between a national register and contemporaneous national population-based eye survey, but highlight low register coverage, and that at least half of all SI resulted from preventable, treatable or curable eye diseases.