An Integrated Approach to Keratoconus Management to Reduce Eye Health Inequity: Investigating Diagnosis, Referral, and Cost

Abstract

Purpose: Assess health disparities and inequities spanning from referral, diagnosis, and treatment including crosslinking, of subjects with keratoconus in New Zealand. Design, methods, approach: This PhD is divided into four main studies; examining the repeatability of commonly used diagnostic devices (topographers and tomographers), examining the referral patterns of optometrists, assessing possible barriers to accessing keratoconus and crosslinking clinics in Auckland, and assessing the financial impact via yearly and lifetime costs of subjects with keratoconus. Data was collected prospectively through online anonymous questionnaires or data collection directly from clinics. We recruited subjects through advertisements at conferences and optometrist magazines, and clinic and private room posters/flyers. Findings: This project identified the Medmont-E300, Revo-NX, and Pentacam-AXL, as the most used corneal imaging devices, and showed low agreeability but high repeatability of devices, suggesting they cannot be used interchangeably when diagnosing or monitoring subjects with keratoconus. Only 56% of optometrists owned a device, of which 81% were topographers. Results identified lack of standardisation in referral patterns, for tertiary assessment or CXL, likely creating heterogeneity in care received by patients. Once referred, attendance was poor (69%) to crosslinking clinics. Results showed Māori and Pacific Peoples present with worse visual acuity, disease severity, and attendance. Low attendance was associated with ethnicity, worse visual acuity, and lower socioeconomic status, and worse visual outcomes were correlated with ethnicity, unemployment, and lack of access to a car. Finally, the estimated cost for patients with keratoconus was estimated to be NZD 1,258 per keratoconus patient per year, totalling an estimated lifetime per capita cost of NZD 79,254 and a total country cost of approximately NZD 30.9 million per year. Originality/value: There is limited research on these specific topics related to keratoconus. Two of the studies have been previously conducted in Australia, however, have not been replicated in New Zealand therefore providing valuable insight into keratoconus management in New Zealand. Our diagnostic device repeatability and barriers to clinic access studies have not previously been investigated and provide valuable insight into keratoconus management in New Zealand and worldwide.