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Abstract
Uncorrected refractive error (URE) is the leading cause of vision impairment globally. URE, particularly uncorrected presbyopia (resulting in near vision impairment), has been a poorly recognised, poorly researched and a poorly prioritised area. This thesis explores the impact and cost-effectiveness of URE correction.
In the health sector, cost-utility analysis is a form of cost-effectiveness evaluation that considers a person’s Quality of Life (QoL) outcomes. These types of evaluations assist governmental resource allocation decisions. A utility value is an indirect measure of a person’s QoL. Utilities have been derived for a variety of ocular and medical conditions but not previously reported for URE.
Cross-sectional research involving 406 refractive error participants was conducted at a university based eye clinic in Sydney. Eye examinations and utility interviews and questionnaires were administered on all participants. Utilities were elicited using the Time-Trade-Off (TTO), Visual Analogue Scale (VAS) and AQol-7D methods.
URE was found to be associated with measurable reductions in QoL using utility analysis. Unaided visual acuity (VA) was found to be a strong predictor of utility with little influence of socio-demographic and lifestyle factors. This suggests results may be generalised to other populations based on the level of VA loss.
Reductions were similar irrespective of whether near or distance vision was impaired but worse when both aspects of vision were affected. This thesis therefore argues for the inclusion of near vision impairment to current global definitions of vision impairment.
Until now, cataract surgery was believed to be one of the most cost-effective interventions globally. Data estimates from this study suggest that intervention aimed at alleviating URE is 40 times more cost-effective than cataract surgery.
Given that URE is the leading cause of vision impairment, the utility values reported here will assist and improve current vision and eye health care prioritisation. These measures provide a basis to more accurately estimate the relative impact and economic consequences of this condition, determine how this compares to other conditions (medical and ocular) and determine the most cost-effective ways to alleviate the unnecessary blindness and impaired vision that results from avoidable causes.