{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,12]],"date-time":"2026-09-12T03:23:35Z","timestamp":1789183415566,"version":"build-2803163510"},"reference-count":49,"publisher":"MDPI AG","issue":"10","license":[{"start":{"date-parts":[[2021,10,18]],"date-time":"2021-10-18T00:00:00Z","timestamp":1634515200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Life"],"abstract":"<jats:p>The size of our pupils changes continuously in response to variations in ambient light levels, a process known as the pupillary light reflex (PLR). The PLR is not a simple reflex as its function is modulated by cognitive brain function and any long-term changes in brain function secondary to injury should cause a change in the parameters of the PLR. We performed a retrospective clinical review of the PLR of our patients using the BrightLamp Reflex iPhone app. The PLR variables of latency, maximum pupil diameter (MaxPD), minimum pupil diameter (MinPD), maximum constriction velocity (MCV), and the 75% recovery time (75% PRT) were associated with significant differences between subjects who had suffered a concussion and those that had not. There were also significant differences in PLR metrics over the life span and between genders and those subjects with and without symptoms. The differences in PLR metrics are modulated not only by concussion history but also by gender and whether or not the person has symptoms associated with a head injury. A concussive injury to the brain is associated with changes in the PLR that persist over the life span, representing biomarkers that might be used in clinical diagnosis, treatment, and decision making.<\/jats:p>","DOI":"10.3390\/life11101104","type":"journal-article","created":{"date-parts":[[2021,10,19]],"date-time":"2021-10-19T22:52:47Z","timestamp":1634683967000},"page":"1104","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":31,"title":["The Pupillary Light Reflex as a Biomarker of Concussion"],"prefix":"10.3390","volume":"11","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-2818-6551","authenticated-orcid":false,"given":"Frederick Robert","family":"Carrick","sequence":"first","affiliation":[{"name":"College of Medicine, University of Central Florida, Orlando, FL 32816, USA"},{"name":"Burnett School of Biomedical Science, University of Central Florida, Orlando, FL 32816, USA"},{"name":"MGH Institute for Health Professions, Boston, MA 02129, USA"},{"name":"Centre for Mental Health Research in Association with University of Cambridge, Cambridge CB2 1TN, UK"},{"name":"Carrick Institute, Cape Canaveral, FL 32920, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Sergio F.","family":"Azzolino","sequence":"additional","affiliation":[{"name":"Carrick Institute, Cape Canaveral, FL 32920, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-6770-4956","authenticated-orcid":false,"given":"Melissa","family":"Hunfalvay","sequence":"additional","affiliation":[{"name":"Carrick Institute, Cape Canaveral, FL 32920, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Guido","family":"Pagnacco","sequence":"additional","affiliation":[{"name":"Carrick Institute, Cape Canaveral, FL 32920, USA"},{"name":"Department of Electrical and Computer Engineering, University of Wyoming, Laramie, WY 82071, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Elena","family":"Oggero","sequence":"additional","affiliation":[{"name":"Carrick Institute, Cape Canaveral, FL 32920, USA"},{"name":"Department of Electrical and Computer Engineering, University of Wyoming, Laramie, WY 82071, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Ryan C. N.","family":"D\u2019Arcy","sequence":"additional","affiliation":[{"name":"BrainNET, Health and Technology District, Vancouver, BC V3V 0C6, Canada"},{"name":"Centre for Neurology Studies, HealthTech Connex, Vancouver, BC V3V 0C6, Canada"},{"name":"DM Centre for Brain Health, Department of Radiology, University of British Columbia, Vancouver, BC V6T 1Z4, Canada"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-6271-3776","authenticated-orcid":false,"given":"Mahera","family":"Abdulrahman","sequence":"additional","affiliation":[{"name":"Health Informatics and Smart Health Department, Health Regulation Sector, Dubai Health Authority, Dubai 7272, United Arab Emirates"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-2788-5457","authenticated-orcid":false,"given":"Kiminobu","family":"Sugaya","sequence":"additional","affiliation":[{"name":"College of Medicine, University of Central Florida, Orlando, FL 32816, USA"},{"name":"Burnett School of Biomedical Science, University of Central Florida, Orlando, FL 32816, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2021,10,18]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"313","DOI":"10.1001\/archneurpsyc.1950.02310270002001","article-title":"Role of sympathetic and parasympathetic systems in reflex dilation of the pupil; pupillographic studies","volume":"64","author":"Lowenstein","year":"1950","journal-title":"Arch. 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