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The Photomotor Response - Dynamic Quantification by a Portable Pupillometer
American Journal of Internal Medicine
Volume 8, Issue 5, September 2020, Pages: 230-236
Received: Jul. 17, 2020; Accepted: Aug. 12, 2020; Published: Aug. 31, 2020
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Jurij Rosen, Department of Neurosurgery Cologne Merheim, University of Witten/Herdecke, Cologne, Germany; Department of Neurology, Faculty of Medicine and University Hospital Cologne, University of Cologne, Cologne, Germany
Claudio Privitera, School of Optometry, University of California, Minor Hall, Berkeley, the United States
Resul Bulmus, Department of Neurosurgery Cologne Merheim, University of Witten/Herdecke, Cologne, Germany
Makoto Nakamura, Department of Neurosurgery Cologne Merheim, University of Witten/Herdecke, Cologne, Germany
Alexander Hartmann, Department of Neurosurgery Cologne Merheim, University of Witten/Herdecke, Cologne, Germany
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The pupillary light reflex (PLR) is a key component of the physical examination as it reliably tests the functional integrity of the neuromuscular loop between pupil and midbrain. Unlike the traditional manual testing the PLR with a penlight that frequently leads to incorrect interpretation due to its subjectivity, the specialized “pupillometer” tool allows objective testing and trending of pupillary data. We performed quantitative unilateral pupillometry several times in 53 healthy subjects (aged 21-74) in different background illumination levels using the NeurOptics NPi®-200 pupillometer. A number of key parameters describing the PLR were collected and analysed. We found that the individual PLR was very consistent. In general, constriction velocity (the first part of the PLR when the pupil constricts promptly after the onset of a light stimulus) was brisker than the dilation velocity (the second part of the PLR, when the pupil recovers from the constriction). Most importantly, both velocities depend on the initial pupillary resting size. We proved that pupillary parameters depend on environmental light conditions and age, but not gender, and scrutinized the nature and dynamics of anisocoric pupils. Taking together, pupillometry is becoming an important, non-invasive clinical tool for testing the autonomic nervous system. Here, we describe baseline parameters representing the physiological PLR, confirming and extending previously reported data. We thus provide the clinician important criteria to precisely assess the PLR and hence the autonomic nervous system in different pathological conditions such as diabetes, traumatic brain injury or cardiac and other autonomic neuropathies.
Quantitative Pupillometry, Pupillary Light Reflex, Pupil Size, Pupillary Dynamics, Neurological Pupil Index, Diabetes, Cardiac Neuropathy
To cite this article
Jurij Rosen, Claudio Privitera, Resul Bulmus, Makoto Nakamura, Alexander Hartmann, The Photomotor Response - Dynamic Quantification by a Portable Pupillometer, American Journal of Internal Medicine. Vol. 8, No. 5, 2020, pp. 230-236. doi: 10.11648/j.ajim.20200805.17
Copyright © 2020 Authors retain the copyright of this article.
This article is an open access article distributed under the Creative Commons Attribution License ( which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
Larson MD, Behrends M. Portable infrared pupillometry: a review. Anesth Analg 2015; 120 (6): 1242-53.
Chen JW, Vakil-Gilani K, Williamson KL, Cecil S. Infrared pupillometry, the Neurological Pupil index and unilateral pupillary dilation after traumatic brain injury: implications for treatment paradigms. Springerplus 2014; 3548.
Du R, Meeker M, Bacchetti P, Larson MD, Holland MC, Manley GT. Evaluation of the portable infrared pupillometer. Neurosurgery 2005; 57 (1): 198-203; discussion 198-203.
Olson DM, Stutzman S, Saju C, Wilson M, Zhao W, Aiyagari V. Interrater Reliability of Pupillary Assessments. Neurocrit Care 2016; 24 (2): 251-7.
Taylor WR, Chen JW, Meltzer H, Gennarelli TA, Kelbch C, Knowlton S, Richardson J, Lutch MJ, Farin A, Hults KN, Marshall LF. Quantitative pupillometry, a new technology: normative data and preliminary observations in patients with acute head injury. Technical note. J Neurosurg 2003; 98 (1): 205-13.
Muppidi S, Adams-Huet B, Tajzoy E, Scribner M, Blazek P, Spaeth EB, Frohman E, Davis S, Vernino S. Dynamic pupillometry as an autonomic testing tool. Clin Auton Res 2013; 23 (6): 297-303.
Bremner FD. Pupillometric evaluation of the dynamics of the pupillary response to a brief light stimulus in healthy subjects. Invest Ophthalmol Vis Sci 2012; 53 (11): 7343-7.
Sharma S, Baskaran M, Rukmini AV, Nongpiur ME, Htoon H, Cheng CY, Perera SA, Gooley JJ, Aung T, Milea D. Factors influencing the pupillary light reflex in healthy individuals. Graefes Arch Clin Exp Ophthalmol 2016; 254 (7): 1353-9.
Privitera CM, Stark LW. A binocular pupil model for simulation of relative afferent pupil defects and the swinging flashlight test. Biol Cybern 2006; 94 (3): 215-24.
Chen JW, Gombart ZJ, Rogers S, Gardiner SK, Cecil S, Bullock RM. Pupillary reactivity as an early indicator of increased intracranial pressure: The introduction of the Neurological Pupil index. Surg Neurol Int 2011; 282.
R Core Team. A language and environment for statistical computing. R Foundation for Statistical Computing, Vienna, Austria. 2018.
Huber A, Kömpf D. Neuroophthalmology. Stuttgart: Georg Thieme Verlag, 1998.
Boev AN, Fountas KN, Karampelas I, Boev C, Machinis TG, Feltes C, Okosun I, Dimopoulos V, Troup C. Quantitative pupillometry: normative data in healthy pediatric volunteers. J Neurosurg 2005; 103 (6 Suppl): 496-500.
Martinez-Ricarte F, Castro A, Poca MA, Sahuquillo J, Exposito L, Arribas M, Aparicio J. Infrared pupillometry. Basic principles and their application in the non-invasive monitoring of neurocritical patients. Neurologia 2013; 28 (1): 41-51.
Rickmann A, Waizel M, Kazerounian S, Szurman P, Wilhelm H, Boden KT. Digital Pupillometry in Normal Subjects. Neuroophthalmology 2017; 41 (1): 12-18.
Sachsenweger R. Neuroophthalmology. Leipzig: VEB Georg Thieme Verlag, 1977.
Pfeifer MA, Weinberg CR, Cook D, Best JD, Reenan A, Halter JB. Differential changes of autonomic nervous system function with age in man. Am J Med 1983; 75 (2): 249-58.
Tekin K, Sekeroglu MA, Kiziltoprak H, Doguizi S, Inanc M, Yilmazbas P. Static and dynamic pupillometry data of healthy individuals. Clin Exp Optom 2018.
Fotiou DF, Brozou CG, Tsiptsios DJ, Fotiou A, Kabitsi A, Nakou M, Giantselidis C, Goula A. Effect of age on pupillary light reflex: evaluation of pupil mobility for clinical practice and research. Electromyogr Clin Neurophysiol 2007; 47 (1): 11-22.
Smith DO, Rosenheimer JL. Factors governing speed of action potential conduction and neuromuscular transmission in aged rats. Exp Neurol 1984; 83 (2): 358-66.
Thurtell MJ, Tomsak RL, Daroff RB. Neuroophthalmology. Oxford - New York: Oxford University Press, 2012.
Shoyombo I, Aiyagari V, Stutzman SE, Atem F, Hill M, Figueroa SA, Miller C, Howard A, Olson DM. Understanding the Relationship Between the Neurologic Pupil Index and Constriction Velocity Values. Sci Rep 2018; 8 (1): 6992.
Lerner AG, Bernabe-Ortiz A, Ticse R, Hernandez A, Huaylinos Y, Pinto ME, Malaga G, Checkley W, Gilman RH, Miranda JJ, Group CCS. Type 2 diabetes and cardiac autonomic neuropathy screening using dynamic pupillometry. Diabet Med 2015; 32 (11): 1470-8.
Jahns FP, Miroz JP, Messerer M, Daniel RT, Taccone FS, Eckert P, Oddo M. Quantitative pupillometry for the monitoring of intracranial hypertension in patients with severe traumatic brain injury. Crit Care 2019; 23 (1): 155.
Oddo M, Sandroni C, Citerio G, Miroz JP, Horn J, Rundgren M, Cariou A, Payen JF, Storm C, Stammet P, Taccone FS. Quantitative versus standard pupillary light reflex for early prognostication in comatose cardiac arrest patients: an international prospective multicenter double-blinded study. Intensive Care Med 2018; 44 (12): 2102-2111.
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