Drive-by Photoscreening [Response to Letter]

Dear editor

Thank you for the opportunity to respond to the excellent and informative letter by Dr. David Hunter.

For our attempt at Drive by Photoscreening,¹ the wire-and-opaque-plastic shielded sufficient ambient light so that blinq could get a reading outdoors, but the performance of blinq suffered compared to conventional indoor use. We surmised this may have been due to the lack of facial view for the aiming beams, but we agree with Dr. Hunter that disruption of infrared light could also have been the culprit.

There remain some potential advantages to a hood, or tent between the patient and the screening device.² These can decrease luminance and stray light. But they also can help fixation. Young and developmentally delayed children often do not understand the need to look at a small fixation target on an instrument-based screener so they may glance at peripheral distractions including the screener’s face. If the screener then tries to “hide” behind the screening device, certain devices show the patient’s face in their monitor so focus and alignment can be accomplished. Such device aiming is inherently obvious with smart phone photoscreening by GoCheck Kids. Viewing the patient’s image on a monitor was not possible with the former MTI photoscreener or the current iScreen photoscreener which also made use of aiming beams like the blinq. In the future, it might be possible to include a small camera that projects the patient’s face to the blinq monitor under these circumstances.

We remain amazed at the technology of the blinq and its potential to shed light on amblyopia, strabismus and perhaps many other entities. We hope the COVID-19 pandemic social distancing guidelines will soon be relaxed to allow even more widespread, valid early amblyopia detection worldwide.