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Evaluation of two portable pupillometers to assess clinical utility
Rachel Eshima McKay1, Michael A Kohn2, Elliot S Schwartz3
1Department of Anesthesia & Perioperative Care, Professor, University of California San Francisco, CA 94143, USA.
Background:
Pupillometers have been proposed as clinical assessment tools. We compared two pupillometers to assess measurement agreement.
Materials & Methods:
We enrolled 30 subjects and simultaneously measured the pupil diameter and light reflex amplitude with an iPhone pupillometer and a portable infrared pupillometer. We then enrolled 40 additional subjects and made serial measurements with each device.
Results:
Failure occurred in 30% of attempts made with the iPhone pupillometer compared with 4% of attempts made with the infrared pupillometer (Fisher's exact p = 0.0001). Method comparison of the two devices used simultaneously showed significant disagreement in dynamic measurements.
Conclusion:
The iPhone pupillometer had poor repeatability and suggests that it is not a practical tool to support clinical decisions.

