Individual Differences in the Post-Illumination Pupil Response to Blue Light: Assessment without Mydriatics
AbstractMelanopsin-containing retinal ganglion cells play an important role in the non-image forming effects of light, through their direct projections on brain circuits involved in circadian rhythms, mood and alertness. Individual differences in the functionality of the melanopsin-signaling circuitry can be reliably quantified using the maximum post-illumination pupil response (PIPR) after blue light. Previous protocols for acquiring PIPR relied on the use of mydriatics to dilate the light-exposed eye. However, pharmacological pupil dilation is uncomfortable for the participants and requires ophthalmological expertise. Hence, we here investigated whether an individual’s maximum PIPR can be validly obtained in a protocol that does not use mydriatics but rather increases the intensity of the light stimulus. In 18 participants (5 males, mean age ± SD: 34.6 ± 13.6 years) we evaluated the PIPR after exposure to intensified blue light (550 µW/cm2) provided to an undilated dynamic pupil. The test-retest reliability of the primary PIPR outcome parameter was very high, both between day-to-day assessments (Intraclass Correlation Coefficient (ICC) = 0.85), as well as between winter and summer assessments (ICC = 0.83). Compared to the PIPR obtained with the use of mydriatics and 160 µW/cm2 blue light exposure, the method with intensified light without mydriatics showed almost zero bias according to Bland-Altman plots and had moderate to strong reliability (ICC = 0.67). In conclusion, for PIPR assessments, increasing the light intensity is a feasible and reliable alternative to pupil dilation to relieve the participant’s burden and to allow for performance outside the ophthalmological clinic. View Full-Text
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Bruijel, J.; Van der Meijden, W.P.; Bijlenga, D.; Dorani, F.; Coppens, J.E.; Te Lindert, B.H.W.; Kooij, J.J.S.; Van Someren, E.J.W. Individual Differences in the Post-Illumination Pupil Response to Blue Light: Assessment without Mydriatics. Biology 2016, 5, 34.
Bruijel J, Van der Meijden WP, Bijlenga D, Dorani F, Coppens JE, Te Lindert BHW, Kooij JJS, Van Someren EJW. Individual Differences in the Post-Illumination Pupil Response to Blue Light: Assessment without Mydriatics. Biology. 2016; 5(3):34.Chicago/Turabian Style
Bruijel, Jessica; Van der Meijden, Wisse P.; Bijlenga, Denise; Dorani, Farangis; Coppens, Joris E.; Te Lindert, Bart H.W.; Kooij, J. J.S.; Van Someren, Eus J.W. 2016. "Individual Differences in the Post-Illumination Pupil Response to Blue Light: Assessment without Mydriatics." Biology 5, no. 3: 34.
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