M&S Technologies News
Back Problems, No Problem for VR Visual Fields
Paul Harris, OD, FCOVD, FACBO, FAAO, FNAP
Professor, Southern College of Optometry
We have all heard the complaints from our patients as we ask them to move forward, put your chin on the chin rest and hold your forehead tight up against the headrest. Many of these complaints we dismiss easily, make an adjustment, and voila, testing can proceed. But some are just beyond what we can successfully navigate, many for reasons we need not enumerate here. For instance, think of some of our wheelchair bound patients or some with significant girth, etc.
In the course of running a study at the University of Iowa Department of Ophthalmology and Visual Sciences, where they are comparing the 24-2 SITA Standard program on the Humphrey Field Analyzer (HFA) to the 24-2 Enhanced testing program on the M&S Virtual Reality (VR) Headset, they ran into a patient with “Kyphosis.” Well, if you are like me, you may need to go look that up. I’ll save you the time. It is an exaggerated, forward rounding of the upper back. It is often caused by a weakness in the spinal bones themselves, causing them to compress or even crack.1
In the end, Dr. Andrew Pouw (Ophthalmological Glaucoma Specialist) and William Najdawi (Medical Student and Research Assistant), wanted to include this 79-year-old woman in the study, but try as they did, she could not get into or maintain proper positioning in the HFA to complete even one eye of testing. Knowing at that point that she would have to be excluded from the study, they switched to patient care mode and knew that they needed a visual field to monitor her condition.
They went to the tried and true, Goldmann visual field device. This is what they came up with (See Figure 1a). But the notes written on the test form were, “Test stopped. Patient answers making no sense. Fixation poor. Eyes all over the place.” So, what to do? They decided to try the M&S VR Headset hoping to get something they could use in the ongoing diagnosis, treatment, and management of her vision. They reported that she was having shooting, neuropathic neck pains while taking the Goldmann.
A 24-2 Full Threshold Test was conducted using the M&S VR Headset and repeated one week later to check for test-retest validity. First, she was able to complete the whole test comfortably, in a reasonable 5 minutes and 27 seconds with only 3 false negatives, no false positives and no fixation losses! Figure 1a shows her visual field. Figure 1b shows the results of her 24-2 full threshold visual field test done on the M&S VR Headset.
During the VR headset testing, she reported no pain or discomfort and was able to perform testing on both eyes, with only a short rest between eyes. This case shows that there are patients who can indeed give us reliable information using the new technology of virtual reality that simply could not have been achieved in any of the older types of tests.
Additionally, we are looking forward to the complete study data coming out of the University of Iowa comparing the HFA and the VR Headset. Preliminary findings are showing statistically faster times with the VR Headset as well as very significant differences in comfort and patient preferences between the two methods of testing as reported by the subjects. Additionally, this comparative study indicates the Mean Deviation and the Pattern Standard Deviation values were similar between the VR headset and the HFA. As clinicians, we are familiar with variations from one testing day to another or even when we redo a test again the same day. The differences between the devices are well within those variations, which we attribute to patient variations from moment to moment, not to any differences between the instrumentation. Thus, adopting this new technology is in the best interests of comfortable patient care, and does not require a special room for testing.
1 https://www.mayoclinic.org/diseases-conditions/kyphosis/symptoms-causes/syc-20374205