Abstract
Purpose :
Visual field testing is a common method for assessing peripheral vision in conditions such as glaucoma, stroke, pituitary disease, and brain tumors. There is an unmet need for an accurate visual field test that is portable, less expensive than current commercially available testing devices, and that could be used for glaucoma screening. Therefore, we developed and tested the efficacy of SimField, an inexpensive visual field test that utilizes a consumer virtual reality headset (Oculus Rift), in glaucoma and glaucoma suspect patients.
Methods :
We developed a software program (SimField) that uses the Oculus Rift Development Kit 2 (DK2) headset to measure visual fields, utilizing a laptop computer for data collection. Based on interpretation of SimField results by two glaucoma specialists and one general ophthalmologist, we developed an algorithm to generate either a positive (abnormal visual field) or negative screening test result. The results of the SimField algorithm were compared to the corresponding gold-standard Humphrey Visual Field Analyzer (HFA) tests to determine sensitivity and specificity. Patients with diagnosed or suspected glaucoma, that had previously undergone HFA exams, were recruited from the University of Chicago Department of Ophthalmology and Visual Science.
Results :
SimField visual field testing was performed successfully on 19 of 20 patients (mean age 70.9) who had previous reliable performance (false positives (FP)<15%, F negatives (FN) <15%, fixation loss (FL) <15%, and difference in mean deviation<1) on two 24-2 SITA standard HFA exams, the most recent of which was within 6 months. SimField testing was performed on 24 eyes, of which 19 had abnormal and 5 had normal previous HFA exams. The SimField exam measured threshold values at the same 54 points as the 24-2 SITA standard software and calculated the FP, FN, and FL. The sensitivity of SimField detection of abnormal visual fields was 94.7% and the specificity was 80%. The mean test performance FP rate was 11.3%, the mean FN rate was 1.5%, and the mean FL rate was 37.8%. Refinement of the technique used in testing of the last ten eyes decreased mean FL to 20.1%.
Conclusions :
SimField appears to be an effective, inexpensive test for identifying glaucomatous visual field loss and can be easily performed with a laptop computer and a cost-effective virtual reality headset.
This is an abstract that was submitted for the 2017 ARVO Annual Meeting, held in Baltimore, MD, May 7-11, 2017.