The Economics of Vision Impairment and its Leading Causes: A Systematic Review

Author: Marques AP, Ramke J, Cairns J, Butt T, Zhang JH, Jones I, Jovic M, Nandakumar A, Faal H, Taylor H, Bastawrous A, Braithwaite T, Resnikoff S, Khaw PT, Bourne R, Gordon I, Frick K, Burton MJ.

Geographical coverage: Not reported

Sector: Impact / Economic evaluation

Sub-sector: Cost

Equity focus: Not reported

Study population: People with visual impairment

Review type: Effectiveness review

Quantitative synthesis method: Meta-analysis

Qualitative synthesis method: Not applicable

Background: Globally, more than one billion people live with visual impairment (VI), the vast majority residing in low- and middle-income countries. Beyond the personal burden, VI imposes heavy economic costs: lost productivity alone is estimated at about US$411 billion per year, and additional expenditures arise from healthcare, service access and complications secondary to sight loss. VI is further linked to higher risks of depression, diabetes, cardiovascular disease and hypertension. Earlier cost studies focused mainly on high-income settings and failed to provide a comprehensive global perspective, underlining the need for an updated synthesis to inform policy and planning.

Objective:

To describe and summarise the costs associated with VI and its principal causes.

Main findings:

The review included 138 studies, of which 38 reported costs for VI of unspecified aetiology; 100 examined specific causes. Most were cost-of-illness (61 %) or cost-analysis (20 %) studies; only 12 % were cost-effectiveness evaluations. Two-thirds of cost estimates originated from high-income countries.

Perspectives and components: Costs were usually presented from a societal (48 estimates) or healthcare-system (25 estimates) viewpoint, but many studies covered only a subset of relevant cost categories. Marked methodological heterogeneity produced wide variation in estimates, and sensitivity analyses were often lacking.

Illustrative average annual treatment costs (per patient, 2018 US$ purchasing-power parity):

• Refractive-error correction: US$12 – 201
• Cataract surgery: US$54 – 3 654
• Glaucoma management: US$351 – 1 354
• Age-related macular degeneration (AMD) treatment: US$2 209 – 7 524

Quality assessment: Mean study-quality score was 78 % (range 35 – 100 %). Frequent weaknesses included absent sensitivity analysis and insufficient cost disaggregation.

A standardised reference case for eye-health economic studies is urgently needed to improve comparability and policymaking relevance.

Methodology:

MEDLINE and the Centre for Reviews and Dissemination databases were searched for partial or full economic evaluations published January 2000 – January 2022 involving adults (≥ 15 years). No language restrictions were applied. Reference lists were hand-searched and experts consulted for grey literature. Two reviewers independently screened titles, abstracts and full texts; disagreements were resolved by consensus or a third reviewer. One reviewer extracted data, which a second checked. Quality was appraised with an adapted BMJ checklist for economic submissions. Costs predating 2018 were inflated to 2018 values using country-specific GDP deflators and converted to US$ PPP to enhance comparability. Results were presented narratively in two groups: (1) general VI and (2) seven specified causes of vision loss.

Applicability / external validity:

Most evidence derives from high-income countries, limiting generalisability to settings where VI burden is greatest. Methodological inconsistency and incomplete cost reporting further hinder cross-study comparison and policy translation. Adoption of harmonised methods and more studies in low- and middle-income contexts would strengthen future estimates.

Geographic focus:

No explicit geographical limits were imposed, yet the distribution of included studies was not detailed.

Summary of quality assessment:

Confidence in the review’s conclusions is high: searches were comprehensive; inclusion criteria transparent; dual-reviewer screening and quality assessment used established tools; and study characteristics were clearly documented. Omission of an excluded-studies list is a minor limitation.