Repeatability of Online Circular Contrast Perimetry Compared to Standard Automated Perimetry

Abstract

Précis: Online circular contrast perimetry provides visual field assessment on any computer or tablet with no extra hardware. It has good test repeatability and reliability that is comparable with standard automated perimetry. It holds promise for use in disease screening and surveillance to expand the provision of glaucoma care. Purpose: To evaluate the repeatability of online circular contrast perimetry (OCCP) compared to standard automated perimetry (SAP) in normal participants and patients with stable glaucoma over 18 weeks. Methods: Thirty-six participants (13 normal controls and 23 patients with open angle glaucoma) were recruited. OCCP and SAP perimetry tests were performed twice at baseline, then at 6, 12, and 18 weeks. Global perimetric indices were compared between perimetry types and analyzed for short-term and intermediate-term repeatability. Results: There were no statistically significant changes over time for both OCCP and SAP across all groups for mean deviation (MD), pattern standard deviation, and visual index/visual field index (P>0.05). Test-retest intraclass correlation coefficients (ICCs) for OCCP MD were excellent at baseline (0.98, 95% CI: 0.89–0.99) and good at 18 weeks (0.88, 95% CI: 0.51–0.98). SAP test-retest ICCs were excellent at baseline (0.94, 95% CI: 0.70–0.99) and 18 weeks (0.97, 95% CI: 0.84–0.99). Inter-test ICCs were good, ranging from 0.84 to 0.87. OCCP testing time was shorter than SAP (5:29 ± 1:24 vs. 6:00 ± 1:05, P<0.001). OCCP had similar false-positive (3.84 ± 3.32 vs. 3.66 ± 4.53, P=0.48) but lower false-negative (0.73 ± 1.52 vs. 4.48 ± 5.00, P<0.001) and fixation loss responses (0.91 ± 1.32 vs. 2.02 ± 2.17, P<0.001). Conclusions: OCCP allows visual field assessment on any computer screen with no additional hardware. It demonstrated good repeatability and reliability with similar performance indices to SAP in both the short term and intermediate term. OCCP has the potential to be utilized as a glaucoma screening and surveillance tool for in-clinic and at-home testing, expanding the provision of care.