The Open Perimetry Initiative: A framework for cross-platform development for the new generation of portable perimeters

Abstract

The Open Perimetry Initiative was formed in 2010 with the aim of reducing barriers to clinical research with visual fields and perimetry. Our two principal tools are the Open Perimetry Interface (OPI) and the visualFields package with analytical tools. Both are fully open source. The OPI package contains a growing number of drivers for commercially available perimeters, head-mounted devices, and virtual reality headsets. The visualFields package contains tools for the analysis and visualization of visual field data, including methods to compute deviation values and probability maps. We introduce a new frontend, the opiApp, that provides tools for customization for visual field testing and can be used as a frontend to run the OPI. The app can be used on the Octopus 900 (Haag-Streit), the Compass (iCare), the AP 7000 (Kowa), and the IMO (CREWT) perimeters, with permission from the device manufacturers. The app can also be used on Android phones with virtual reality headsets via a new driver interface, the PhoneHMD, implemented on the OPI. The use of the tools provided by the OPI library is showcased with a custom static automated perimetry test for the full visual field (up to 50 degrees nasally and 80 degrees temporally) developed with the OPI driver for the Octopus 900 and using visualFields for statistical analysis. With more than 60 citations in clinical and translational science journals, this initiative has contributed significantly to expand research in perimetry. The continued support of researchers, clinicians, and industry are key in transforming perimetry research into an open science.

A Practical Framework for the Integration of Structural Data Into Perimetric Examinations

“…Our perimetric strategies were implementations of the Zippy Estimation through Sequential Testing (ZEST) procedure. 19 Our procedure was based on the implementation of ZEST provided within the OPI package 17 , 18 for R (R Foundation for statistical computing, Vienna, Austria). Briefly, a prior distribution of possible outcome values between 0 dB and 40 dB is updated using a likelihood function based on the responses from the subject to each presentation (seen or not seen).…”

“… 15 The Compass has been shown to have equivalent diagnostic precision to the Humphrey Field Analyzer (Zeiss, Dublin, CA) 16 and improved test-retest variability for the measurement of mean sensitivity. Besides its native commercial software, the CMP can be controlled through the Open Perimetry Interface (OPI), 17 , 18 which facilitates the practical implementation and evaluation of novel experimental testing procedures.…”

Validation of the Iowa Head-Mounted Open-Source Perimeter

“…The smartphone ran a custom Android application (open-source code available at https://github.com/imarinfr/opiPhoneHMD ). A separate computer ran an R (R Foundation for Statistical Computing, Vienna, Austria) shiny application 8 (open-source code available at https://github.com/imarinfr/opiApp ) which allowed direct control of both the HMD (through the custom Android application on the smartphone) and the Octopus 900 using the Open Perimetry Interface (OPI)—an open-source system designed to control perimeters with the goal of decreasing barriers to perimetry research and increasing access to visual field testing. 8 , 9 The zippy estimation of thresholds (ZEST) algorithm implemented within the OPI was used to determine individual location sensitivities and was coupled with the Central 26 grid pattern ( Fig.…”