Related Experiment Video
Updated: Aug 2, 2026

Assessing Early Stage Open-Angle Glaucoma in Patients by Isolated-Check Visual Evoked Potential
Published on: May 25, 2020
Online Circular Contrast Perimetry via a Web-Application: Establishing a Normative Database for Central 10-Degree
Yang X Chen1, Joshua Meyerov2, Simon E Skalicky2,3
1St Vincent's Hospital Clinical School, University of Melbourne, Melbourne, VIC, Australia.
Purpose:
To establish a normative database using a central 10-degree grid pattern for the online circular contrast perimetry (OCCP) application.
Participants:
Fifty participants with mean age 65 ± 13 years were selected for this study. One eye from each participant that met inclusion criteria was randomly included in the cohort.
Methods:
The web-application delivered online 52-loci perimetry in a central 10-degree pattern using circular flickering targets. These targets consist of concentric sinusoidal alternating contrast rings. Users were guided by the application to the correct viewing distance and head position using in-built blind spot localization and webcam monitoring. A spinning golden star was used as the fixation target and patients performed the test in a darkened room following standard automated perimetry (SAP).
Results:
The reliability rates and global indices for OCCP were similar to SAP. OCCP mean sensitivity reduced with age at a similar rate to SAP. Mean sensitivity per loci of 10-degree OCCP was greater than SAP by 1.24 log units (95% CI 1.23 to 1.26) and obeyed a physiological hill of vision. Small differences existed in mean sensitivities between OCCP and SAP which increased with increasing spot eccentricity. Mean deviation (MD) displayed good agreement between the two tests.
Conclusion:
Central 10-degree online circular contrast perimetry via a computer-based application has comparable perimetric results to standard automated perimetry in a normal cohort.
Related Concept Videos
Calculating Standard Deviation
The standard deviation value is small when all the data is concentrated close to the mean. Here the data exhibits low variation. The standard deviation value is larger when the data values are more spread out from the mean. Here, the data displays high variation.
Let us...
Standard Deviation of Calculated Results
A broad Gaussian distribution curve has a wider standard deviation, representing a data set with...
Measurement of Air Content in Concrete
The pressure method,...
Distance Measurements by Taping
Distance Corrections
Design Example: Measuring Distance Between Two Points with Obstructions

