Photophobia is a frequent complaint following traumatic brain injury (TBI) and sometimes lasts longer than 1 year, according to research published in Optometry and Vision Science. More commonly, though, it lasts approximately 3 months.
Occurrence of photophobia relies predominantly upon patient reports and questionnaires. The meta-analysis aimed to assess when photophobia manifests following TBI.
Researchers reviewed the literature on photophobia in patients with diagnosed TBI or concussion who experienced photophobia within 12 months of diagnosis. They included 75 studies (27,942 individuals, 7794 with photophobia) from PubMed, EMBASE, and Cochrane Library that were published before September 2019.
The majority (n=41) of studies were conducted in the US or by Americans at foreign military bases, while others were conducted in Australia, New Zealand, Canada, and countries in Europe and Asia. Assessments were predominantly via survey or questionnaire.
The number of patients with photophobia decreased as time since injury increased, particularly during the first 3 months. One week after the injury, 30.46% of patients experienced photophobia. That portion decreased to 19.34% at 1 month following the injury and 13.51% by 3 months after the injury. Photophobia increased between 3 and 6 months to 17.68% and decreased between 6 and 12 months, to 14.85%.
In model-based analysis, photophobia decreased from initial injury up to 3 months after the injury (OR 0.74 P <.001), followed by a minor increase to 1 year (1.03 P =.02). Individuals in the military (OR 5.08 P <.001) and sports (OR 2.01 P =.02) were more likely to experience TBI compared with the general population.
In 14 studies that compared patients with TBI (n=2084, 615 with photophobia) with control individuals (n=2233, 153 with photophobia), photophobia prevalence again decreased as time since injury increased (P <.001). In an analysis of time-adjusted prevalence, the patients with TBI were nearly 6 times more likely (OR 5.75 P <.001) to experience photophobia compared with control individuals.
Individuals with traumatic brain injury maintained a higher risk of having photophobia compared with control group individuals, through 1 year since injury.
The research team advocated for a photophobia-dedicated validated questionnaire for patients with TBI in an effort to improve the understanding of its natural history, and its relative effectiveness of rehabilitation.
Limitations of the study included a lack of demographic and patient-specific TBI history that could have analyzed variations in TBI and comorbid conditions and possible confounding factors.
Merezhinskaya N, Mallia RK, Park D, et al. Photophobia associated with traumatic brain injury: a systematic review and meta-analysis. Optom Vis Sci. 2021;98:891-900. doi:10.1097/OPX.0000000000001757