Retinal Layer Thickness and Volume Measurements in Traumatic Brain Injury

Purpose: To assess retinal layer thickness and volume by optical coherence tomography (OCT) in patients with prior traumatic brain injury (TBI). Methods: Adults (≥18 years) with prior TBI were prospectively recruited. 512 × 128-mm macular cube scans were obtained using Zeiss Cirrus HD-5000 OCT. The previously validated Duke Reading Center's DRCVisualizer semiautomatically segmented (manually corrected) the ganglion cell-inner plexiform (GC-IPL), inner nuclear (INL), outer plexiform (OPL), outer nuclear (ONL), photoreceptors (PR), and retinal pigment epithelium (RPE) layers. Mean thickness and volume were obtained within 3- and 6-mm ETDRS perifoveal rings. Individuals were age- and sex-matched (±5 years) with controls. Results: Thirty-eight patients with TBI (66 eyes; mean ± SD age 45 ± 19 years) and 37 controls (66 eyes; age 44 ± 18 years) were enrolled. Time from TBI to imaging was a mean ± SD 136 ± 89 weeks. TBI was categorized by severity (mild without loss of consciousness [LOC] [n = 25], mild with LOC [n = 35], moderate [n = 6]) and injury mechanism (nonpenetrating contact [n = 54], acceleration-deceleration [n = 12]). Mean GC-IPL was significantly decreased and mean OPL thickness and volume were significantly increased in male TBI patients versus controls. Eyes with moderate TBI had significantly increased mean neurosensory retina, INL, OPL, and RPE thickness and volume versus other TBI severity groups. Eyes with nonpenetrating contact TBI had significantly increased mean neurosensory retina and ONL thickness and volume versus eyes with acceleration-deceleration TBI. All eyes showed a significant correlation for decreasing mean GC-IPL thickness and volume with time from TBI to imaging. Conclusions: TBI may impact thickness and volume of the retinal layers, and changes may be progressive over time.