Table 3.

Study Characteristics.

Study	Year	Design	Location	Setting	Sample size	Mean age (y) ± SD (range)	Female (%)	Target population	Severity	Diagnostic criteria	Causes of TBI	Time since TBI	OCT type	OCT time points	Comparator
Chan et al. [36]	2019	Retrospective	USA	Single centre	19	37.0 ± 11.8 (27 - 67)	1 (5.3)	Military (veterans)	Mild	VA/DoD	53% blast, 42% blunt, 5% blunt + blast	At least 6 months	Spectralis SD-OCT	Once	4 healthy male controls. Mean age 27± 1years
Gilmore et al. [34]	2020	Prospective longitudinal	USA	Minneapolis VA Healthy Care System	69	50 ± 10.3	7 (10.1)	Military (veterans)	Mild	Mayo	Blast and non-blast	Median (range) 17 (0.5–59) years	Cirrus SD-OCT	Median 4 (3 or more included in analysis)	70 matched healthy controls
Kumar Das et al. [35]	2022	Prospective longitudinal	India	Single Tertiary healthy care hospital	60	N/A (63.4% less than 45 years old)	24 (40)	Civilians	Mild	WHO	Doesn’t specify	7 days	Cirrus HD-OCT	7 days, 3 months, 6 months, 1-year post trauma	None

VA/DoD United States Department of Veterans Affairs/Department of Defense, WHO World Health Organisation, SD-OCT Spectral Domain-Optical Coherence Tomography, HD-OCT High Resolution Spectral Domain-Optical Coherence Tomography.