Online Circular Contrast Perimetry: A Comparison to Standard Automated Perimetry

Abstract

Purpose: The aim was to validate and compare the diagnostic accuracy of a novel 24-degree, 52-loci online circular contrast perimetry (OCCP) application to standard automated perimetry (SAP). Design: Prospective cohort study. Methods: Two hundred and twenty participants (125 normal controls, 95 open angle glaucoma patients) were included. Agreement, correlation, sensitivity, specificity, and area under receiver operating curves (AUC) were compared for parameters of OCCP, SAP, and optical coherence tomography (OCT) for the retinal nerve fiber layer and macular ganglion cell complex inner plexiform layer. Results: Pointwise sensitivity for OCCP was greater than SAP by 1.02 log units (95% CI: 0.95–1.08); 95% limits of agreement 0.860 to 1.17. Correlation and agreement for global indices and regional zones between OCCP and SAP were strong. OCCP mean deviation (MD) AUC was 0.885±0.08, similar to other instruments’ parameters with the highest AUC: SAP MD (0.851±0.08), OCT retinal nerve fiber layer inferior thickness (0.908±0.07), OCT ganglion cell complex inner plexiform layer inferior thickness (0.849±0.08), P>0.05. At best cutoff, OCCP MD sensitivity/specificity were comparable to SAP MD (90/74 vs 94/65%). Conclusions: OCCP demonstrates similar perimetric sensitivities to SAP and similar AUC to SAP and OCT in distinguishing glaucoma patients from controls. OCCP holds promise as a glaucoma surveillance and screening tool, with the potential to be utilized for in-clinic and at-home perimetry and expand community testing.

Online Circular Contrast Perimetry via a Web-Application: Establishing a Normative Database for Central 10-Degree Perimetry

“… 21 24–2 OCCP is comparable to SAP in distinguishing diseased states from normal eyes, particularly in diagnosing glaucoma. 19 …”

“…Good agreement for MD results between OCCP and SAP was found which is consistent with previous studies evaluating computer-based OCCP and in tablet-based perimetry. 13 , 19 …”

“…On average, the OCCP test duration was 1:20 (minutes: seconds) longer than SAP, in contrast to our recent studies which found similar test durations between OCCP and SAP. 19 , 20 This discrepancy is likely a consequence of the formal double staircase algorithm that was used to determine the normal thresholds at each test locus. 21 Now that this has been determined, probability density functions (PDFs) that are an essential component of modern perimetry such as SITA algorithms 42 , 52 , 53 can be used to more rapidly determine thresholds.…”

“…A full description of the OCCP methodology for assessing perimetry has been outlined previously. [19][20][21] In brief, OCCP utilizes flickering circular targets to assess visual sensitivity. These targets are similar to those in Pulsar perimetry (Haag-Streit International, Bern, Switzerland) with the same level of contrast in all radial directions, to avoid stimulation of those cells that selectively respond to a given orientation, but differ from Pulsar spots by being smaller in size and of consistent contrast throughout the spatial extent of the target despite a thin rim of contrast reduction at the peripheral target edge.…”

“… 17 , 18 Studies comparing OCCP to SAP have shown favorable results, in terms of similar perimetric outcomes, similar diagnostic accuracy, and an improved user experience. 19 , 20 A normative database for the central 24 degrees of vision has been established using OCCP; we now wish to demonstrate the feasibility of and establish a normative database for central 10-degree OCCP perimetry. 21 …”