Abstract
Purpose :
We developed a visual field test (VFT) that can run in a head-mounted display (HMD). The software that powers this test allows for the ability to run monocular and binocular VFTs, with the binocular VFTs being available at a variety of different viewing distances. Running VFTs at different simulated viewing distances will allow for a better understanding of the interaction between scotomas in two eyes as a function of the vergence angle. We hypothesize that the varying overlap and binocular interaction of monocular scotomas affects patients' functional vision.
Methods :
The VFT software was written using Unity, an engine that allows for the development of software that can run in HMDs. Initially, a monocular test was created and rigorously tested. The program was then augmented with a binocular test that runs on the same base software. A 10-2 test was also added to acquire the necessary resolution to test the hypothesis. In the binocular VFT, vergence angle is changed by moving the fixation cross along the virtual z axis. Each stimulus location stores its own data, such as responses at various brightness levels. Once the test is complete, a Weibull function is fit to the data to find the subject’s sensitivity at each location. These sensitivities are then output to a results file for analysis.
Results :
Preliminary results have allowed us to validate the functionality of our VFT against a standard Humphrey test. We have also seen that patients have different sensitivities in the binocular test at different viewing distances. For example, patient 008, who has known scotomas in both eyes, had a binocular scotoma at (-1, 1) degrees when testing at 60 cm and one around (5, 7) when testing at 300 cm. These results are displayed in the figures.
Conclusions :
We currently have a functional binocular VFT that has been verified against a standard Humphrey VFT. We have already begun collecting patient data with promising results. We plan on running VFTs for each subject at all of the simulated viewing distances in the binocular test, as well as one monocular VFT in each eye. Using the combined data that we receive from the subjects, we will work on finding a function that can predict how scotomas will overlap at different vergence angles.
This abstract was presented at the 2024 ARVO Annual Meeting, held in Seattle, WA, May 5-9, 2024.