Online circular contrast perimetry: Tablet validation study against desktop test and standard automated perimetry

To assess correlation, agreement and diagnostic accuracy of a new tablet-based 24-degree, 52-point online circular contrast perimetry application (OCCP), compared to computer-based OCCP and standard automated perimetry (SAP).

Seventy-five participants (26 controls, 49 glaucomatous) were tested via SAP using Humphrey field analyzer (Zeiss), then by computer OCCP on a 24-inch monitor, followed by two OCCP tests on a tablet (iPad Air 5th gen). Key outcome measures included pattern standard deviation (PSD), mean deviation (MD), mean sensitivity per point, and visual field index (VFI)/visual index (VI).

Agreement and correlation of VFI, PSD, and MD between OCCP tablet and SAP were very strong, with spearman's ρ and intra-class correlation coefficients between 0.81-0.86 and 0.80-0.93, respectively. MD Bland-Altman bias was greater for OCCP tablet against SAP-0.53 to 0.68 dB-compared to OCCP computer against SAP at 0.05 dB. 95% limits of agreement were comparable for OCCP versus SAP. Point-by-point Bland-Altman bias demonstrated tighter agreements between OCCP tablet and OCCP personal computer (PC) compared to OCCP generally and SAP. Receiver-operating-characteristic curves were comparable across outcomes between all OCCP tests, SAP, and cirrus optical coherence tomography parameters with no significant differences. Test duration was longer for OCCP tablet than SAP, whereas OCCP PC was shorter than SAP (p < 0.001).

OCCP tablet has strong correlation, agreement, and similar area-under-curve in identifying glaucomatous eyes from controls to both SAP and OCCP computer, demonstrating prospect as a tool for glaucoma perimetry testing in low-resource settings, with further enhancements to reduce test duration.