Related Experiment Video
Updated: Aug 14, 2026
Controlled Cortical Impact Model for Traumatic Brain Injury
Published on: August 5, 2014
Elevated dark adaptation thresholds in traumatic brain injury
T Du1, K J Ciuffreda, N Kapoor
1Department of Vision Sciences, State University of New York/State College of Optometry, New York 10036, USA.
Primary Objective:
To expand upon earlier findings of elevated dark adaptation (scotopic) thresholds in photosensitive individuals with traumatic brain injury (TBI).
Methods And Procedures:
To assess scotopic thresholds in individuals with TBI (n = 17) manifesting varying degrees of photosensitivity (mild, moderate or marked), but without retinal dysfunction, to those of non-photosensitive, visually-normal individuals (n = 21) using a hand-held dark adaptometer.
Main Outcomes And Results:
The group mean scotopic threshold for the TBI group was significantly higher than that of the visually-normal group. Over 50% (nine out of 17) of the TBI group exhibited elevated thresholds. There was no correlation between the threshold value and degree of photosensitivity.
Conclusion:
The elevated scotopic thresholds suggest an abnormality in cortical gain control. An anomalous adaptive response may develop due to cortical damage, thereby attenuating subjective light sensation.
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