Comparing Online Circular Contrast Perimetry and the Esterman Visual Field Test in Glaucoma for Driving-Relevant Vision

Precis: Online binocular perimetry showed moderate to strong agreement with Esterman visual field testing in glaucoma patients and controls, with high correlation coefficients and predictive capability. This tool may offer a viable, accessible alternative perimetry for driving licence assessment. Purpose To assess the feasibility of an online computer-based binocular driving perimetry assessment (OBDP) based on online circular contrast perimetry, and agreement with binocular static Esterman visual field testing (EVFT). Methods: A prospective comparative cohort study was conducted on patients with or without open-angle glaucoma, recruited from a single site glaucoma subspecialty practice. Eligible subjects underwent two visual field tests using OBDP and this was compared to the results of a single EVFT. Results: 80 patients were enrolled in the study, with a mean age of 69 years (+/- 13.4 SD). Of these, 49% were female, 18 were healthy controls, while 20, 18 and 24 had mild, moderate and severe glaucoma respectively. Pearson and intraclass correlation between the two perimetry methods for percentage of points not seen (PNS) was 0.85 and 0.86 (95% confidence interval (CI) 0.78–0.9) respectively for the overall binocular visual field. When the binocular field was subdivided into 8 sectors, intra-class coefficients (ICCs) ranged from 0.76 to 0.93 for each sector. Bland-Altman analysis revealed a difference of 1.24% (95%CI -16.93 to 19.30%) between the two methods for the overall field, ranging from 0.04% to 4.17% for each sector. Based on the Austroads fitness to drive guidelines, OBDP demonstrated a sensitivity of 96.97% and specificity of 78.57% when compared to the EVFT. ICCs evaluating the repeatability of OBDP testing for percentage of PNS were excellent overall (0.97) and ranged from moderate to excellent for each of the 8 sectors (0.67 – 0.98). Conclusion: OBDP showed strong agreement with EVFT. As an online application that easily runs on any computer, it could expand the scope of binocular perimetry screening for licence assessment. With modifications, integration into modern clinical licencing procedures could be considered.