EyeWorld is the official news magazine of the American Society of Cataract & Refractive Surgery.
Issue link: https://digital.eyeworld.org/i/422211
13 EW NEWS & OPINION by David F. Chang, MD the hardware itself causes a periph- eral scotoma. For this we conduct- ed standard automated perimetry with a Humphrey device at 30 and 60 degrees of visual field interro- gation. The scotomas were clearly demonstrable even in a handful of subjects—all in the right temporal hemifield subtended by the blocking effect of the protruding frame. We believe this is the first time that clinical-grade Humphrey perim- etry has been used to characterize and quantify the visual field impact of Google Glass. We compared Google Glass to one of the larger frames available in the office and discovered that the Google Glass effect was much more pronounced. We also found that the effect varied with head anatomy, interpupil- lary distance, and fitting. We then conducted another embedded evaluation of how people wear the device. We reviewed more than 100 images of people wearing Google Glass, which were obtained from the Internet through a Google search. In all evaluable images the anatom- ic position of the hardware with respect to visual/pupillary axis was assessed and graded. Our hypothesis was substantiated—i.e., most people seem to wear the head-mounted display with the prism in a cen- tral or paracentral position, which appears to correlate with larger and Dr. Chang: What prompted you and your collaborators to assess the im- pact of the Google Glass device on peripheral vision, and what testing did you perform? Dr. Ianchulev: This was quite seren- dipitous. As a technology aficionado from the San Francisco Bay Area, I was one of the "early adopters" at the beginning of this year. I tried Google Glass and really liked its de- sign and potential to transform how we interact with technology and ac- cess information. I was thrilled with the device until I almost got into a car accident when wearing it while driving. I realized then that a large part of my visual field was blocked by the bulky hardware of the device. I went home and did a quick online perimetry test, which demonstrated the scotoma in the temporal right hemifield. I shared my observations with several colleagues in academia, and almost immediately an ad-hoc research team was formed with Drs. Koo, Hoskins, Minckler, Stamper, Packer, and Pamnani. Everyone grasped the big issue here—with thousands of devices out there po- tentially causing absolute functional scotomas in active, energetic people who drive, cycle, and jog while wearing head-mounted devices, we felt there was a potential safety risk that needed to be understood. We felt it was better to be proactive, rather than find out later about potential dangers through DMV statistics. I think that in the excitement that surrounded the introduction of this new technology, a basic question of whether wearing the device would put the wearer or others at risk of harm was perhaps overlooked. Dr. Chang: What were the findings reported in JAMA? Dr. Ianchulev: We gleaned signif- icant insight into the interaction between a head-mounted elec- tronic display and visual function, even though this was a very small, focused investigation without any government or industry spon- sorship. There were several main aspects of the study methodology and associated findings. First, we wanted to show specifically whether G oogle Glass is the promising wearable technology that everyone seems to be talking about. In 2012, Time magazine voted it one of the "Best Inventions of the Year," and any of us can now purchase this smart device online for $1,500. For ophthalmologists, the irony is that just about when our refractive technologies become good enough to provide spectacle independence for the majority of our patients, they may still want to wear glasses thanks to Google! Last month, University of California, San Francisco ophthalmologist Sean Ianchulev, MD, and colleagues published a study in JAMA that made national news by pointing out an unrecognized potential hazard of this wearable device—a significant visual field scotoma. Peri- metric testing revealed that, depending on how it is worn, the frame hardware design creates a variable sized right upper quadrant scotoma. This clearly has important safety implications because of the numerous applications for users who are driving, walking, and exercising. When Sean first told me about this, I could not help but think of Steve Martin's 1979 film The Jerk. Martin's character became an instant millionaire by in- venting a spectacle frame attachment called the "Opti-Grab" to prevent glasses from sliding down one's nose (Google "Opti-Grab" to see the movie scene). Unfortunately, his invention also caused permanent esotropia, and he was bankrupted by the ensuing class action litigation. Of course, the size of Google's investment in this project is no laughing matter, and there will undoubtedly be further study and design modification to address this issue. Sean was one of 3 ophthalmologists I interviewed for my column on venture capital last month. He has been an active inventor and is no stranger to the challenges of technical innovation. As an ophthalmology resident, Sean worked on the idea of IOL power determination using intraoperative refractive biometry. After the major surgical companies initially spurned the idea, his patented concepts were eventually developed by a startup company—WaveTec— whose acquisition by Alcon was announced several months ago. He also pioneered the first web-based, telemedicine perimetric screening system for glaucoma and age-related macular degeneration (KeepYourSight Foundation). I am not surprised that Sean was one of the first consumers to purchase Google Glass. But leave it to him to be the first to self-diag- nose a peripheral scotoma that he confirmed by testing himself at home on his own web-based perimetric screening program. This month, Sean recounts the story behind this accidental discovery. David F. Chang, MD, chief medical editor Google Glass—A developmental blind spot December 2014 Dr. Ianchulev wearing his Google Glass device. continued on page 15 deeper scotomas. This is concerning, especially if people engage in driving or high-velocity activities while wearing the device. Dr. Chang: What are the implica- tions of these findings? Dr. Ianchulev: The impact of having a significant scotoma in your visual field is very well established through many studies on glaucoma patients. We know it impacts driving, and can lead to falls and occupation- al hazards. What compounds the situation here is that people using Google Glass tend to be younger and significantly more active than the typical glaucoma patient. Thus the potential for harm to the users or those around them is magnified. Dr. Chang: What had Google pre- viously done to assess the potential impact of the device on functional vision? What has been their reaction to your study? Dr. Ianchulev: We contacted Google to share this information, as we were unable to find anything written about this in the public domain. We reached out to them before our study was published because we heard they were collabo- rating with auto companies, such as Mercedes Benz, to integrate Google Glass in cars—which we thought might not be a very good idea given our findings. They immediately responded and engaged with us with a genuine interest to understand and try to solve the problem. I think this issue was not one that they had foreseen. We continue to dialogue with them as we have gained some interesting insight from our study on how factors such as head mor- phology, pupillary distance, device adjustments, and proper fitting can impact the degree of the scotoma. I believe this is a solvable issue and quite important given the many use- ful applications of this technology. Dr. Chang: Do you have thoughts on how the device could be designed or worn more safely? Dr. Ianchulev: Yes, we have some ideas, but we need to study this further. Our team was an ad-hoc Chief medical editor's corner of the world