The societal economic impact of vision impairment in adults 40 years and above: findings from the National Eye Survey of Trinidad and Tobago.

BACKGROUND: Understanding and mitigating the societal economic impact of vision impairment (VI) is important for achieving the Sustainable Development Goals. AIM: To estimate the prevalent societal economic impact of presenting VI in Trinidad and Tobago using bottom-up cost and utilisation data from the 2014 National Eye Survey of Trinidad and Tobago. METHODS: We took a societal perspective to combine comprehensive, individual-level cost and utilisation data, with population-based prevalence estimates for VI, and additional data from a contemporaneous national eyecare system survey. We included direct (medical and non-medical) and indirect (productivity loss) costs, and intangible losses in total cost estimates, presented in 2014 Trinidad & Tobago (TT) dollars and UK sterling equivalent. We considered but excluded transfer payments and dead weight losses. Sensitivity analyses explored impact on total cost of parameter uncertainty and assumptions. RESULTS: Individual utilisation and cost data were available for 65.5% (n = 2792/4263) and 59.0% (n = 2516/4263) eligible participants aged ≥40 years, respectively. Participant mean age was 58.4(SD 11.8, range 40-103) years, 56.3% were female. We estimated total societal cost of VI in 2014 at UK£365,650,241 (TT$3,842,324,655), equivalent to £675 per capita (population ≥40 years). Loss of wellbeing accounted for 73.3%. Excluding this, the economic cost was UK£97,547,222 (TT$1,025,045,399), of which indirect costs accounted for 70.5%, followed by direct medical costs (17.9%), and direct non-medical costs (11.6%). CONCLUSION: This study provides a comprehensive estimate of the economic impact of vision loss in a Caribbean country, and highlights the extent to which affected individuals and their families bear the societal economic cost of vision impairment.

Diagnostic features of the autoimmune retinopathies.

The term autoimmune retinopathy encompasses a spectrum of rare autoimmune diseases that affect retinal function, often but not exclusively at the level of the photoreceptor. They typically present with painless visual loss, which may be accompanied by normal fundus examination. Some are progressive, often rapidly. They present a diagnostic challenge because there are no standardised clinical or laboratory based diagnostic criteria. Included within the spectrum are cancer-associated retinopathy, melanoma-associated retinopathy and presumed non-paraneoplastic autoimmune retinopathy. Differentiation from other retinopathies can be challenging, with overlap in symptoms, signs, and investigation findings, and an absence of pathognomonic features. However, technological developments in ophthalmic imaging and serological investigation over the past decade are adding novel dimensions to the investigation and classification of patients with these rare diseases. This review addresses the clinical, imaging, and serological features of the autoimmune retinopathies, and discusses the relative strengths and limitations of candidate diagnostic features.

Autoimmune retinopathy.

Autoimmune retinopathy encompasses a spectrum of rare autoimmune diseases that primarily affect retinal photoreceptor function, and include cancer-associated retinopathy (CAR), melanoma-associated retinopathy (MAR) and presumed non-paraneoplastic autoimmune retinopathy (npAIR). Autoimmune retinopathy typically presents in the fifth and sixth decades with rapidly progressive, bilateral, painless visual deterioration but an unremarkable fundus examination. CAR, MAR and npAIR have an overlapping clinical phenotype, and extensive investigation is required to exclude other causes of retinopathy, and to identify any occult malignancy, before a presumptive diagnosis can be made. Delayed diagnosis, and treatment initiation relatively late in the disease course, may contribute to the poor visual prognosis. Various treatments have been attempted, including systemic immunosuppression with steroid and steroid-sparing agents, intravenous immunoglobulin, and plasmapheresis, but these lack an evidence base. A variety of antiretinal antibodies have been identified in patients with autoimmune retinopathy, including antibodies to recoverin, α-enolase and transducin-α, but seronegative disease is also common. Clinical access to specialised serological investigation is very limited internationally, and this exacerbates the management challenge presented by patients with suspected autoimmune retinopathy. Several decades of experimental research have resulted in very considerable advances in our understanding of the pathophysiological mechanisms that may underlie autoimmune retinopathy. However, the precise triggers which result in loss of ocular immune privilege and sudden autoimmune attack on retinal cells have yet to be elucidated. This review summarizes the classification, investigation and management of autoimmune retinopathy, and considers the evolving concepts about its immunological aetiology.

Dextrose and sorbitol as diluents for continuous intravenous heparin infusion.

A comparison of 5% dextrose and 5% sorbitol as diluents for heparin given by continuous intravenous infusion indicated that neither impaired the potency of the heparin. Previous suggestions that heparin becomes unstable in dextrose solution have not been confirmed.