CET feedback: Dry eye VRICS

We recently ran a visual recognition and interpretation exercise concerning the assessment of dry eye. Here are the answers with a few explanatory comments.

Q1 Watch the video. It begins immediately after a blink. Which of the following best describes the fluorescein break-up time?

Answer B. By running the video, a small darker patch is clearly seen to appear at around four seconds, just to the upper left of the central pupil. Obviously, the darker areas are where there is no fluorescein. These may be detected more sensitively when an orange absorption filter is used in combination with the blue excitation filter. Also, as viewers of the game show The Cube will be know, many of us are very poor at counting in seconds and often under or over-estimate time significantly. Use of a video with timer, a stopwatch or smartphone timer is well worth introducing into your routine.