Assessment of pupil size under different light intensities using the Procyon pupillometer

To study the relationship between pupil size and light intensity using the Procyon pupillometer.University based clinic.In this retrospective study, 20 consecutive patients had pupil size assessment with the Procyon pupillometer under 3 different light conditions--4, 0.4, and 0.04 lux. Correlation was established using the log unit of the light intensity and pupil size.The correlation coefficient for the association between pupil size and log unit of light intensity in all eyes was significant (P<.001). The mean correlation coefficient for the association between pupil size and log unit of light intensity in all patients was 0.968 +/- 0.089 (SD) in the right eye and 0.970 +/- 0.031 in the left eye.The linear relationship between the pupil size and the log unit of the light intensity showed a tight correlation in all cases. These results can be useful in the comparing pupil size with pupillometers that work under different light conditions.