Eye and Brain (Dec 2018)
Investigating possible retinal biomarkers of head trauma in Olympic boxers using optical coherence tomography
Abstract
Charmaine Childs,1 Lynne A Barker,2 Alex MD Gage,3 Mike Loosemore4 1Faculty of Health and Wellbeing, Sheffield Hallam University, Sheffield, South Yorkshire, UK; 2Centre for Behavioural Science and Applied Psychology, Sheffield Hallam University, Sheffield, South Yorkshire, UK; 3Alex Gage Family Optometrist, Sheffield, South Yorkshire, UK; 4Institute of Sport, Exercise and Health (ISEH), London, UK Purpose: Changes to retina have been reported after a number of neurodegenerative conditions. The purpose of this study was to investigate retinal structures in Olympic boxers exposed to frequent head blows. Methods: Retinal imaging offers potential as a non-invasive biomarker of neuropathology. Macula and retinal nerve fiber layer (RNFL) thickness was measured using optical coherence tomography (OCT) in UK Olympic boxers attending two mandatory eye screening programs, 18 months apart. Data from the two eye screenings provide longitudinal data of retinal change over time. Sedentary healthy subjects (controls) without past or present history of concussion were also screened at the time of the second boxer screening to provide comparison of cross-sectional data. Results: Sixteen Olympic boxers aged 20–33 years and 20 sedentary healthy controls, aged 24–45 years, were recruited. Significant macula thickening was observed over time (18 months) in 75% of right and 50% of left eye sectors. For RNFL, left eye quadrants thickened. For right eye RNFL quadrants, thickening and thinning of this layer were observed. Cross-sectional results showed thinner macula sectors and RNFL quadrants in Olympic boxers compared to controls. Conclusion: Significant change to macula and RNFL densities, occurring over an 18 month interval is an unexpected finding in otherwise heathy elite sportsmen. In addition, macula and RNFL were thinner than healthy sedentary controls. OCT may prove clinically useful as a candidate retinal biomarker of neuropathological change after mild traumatic brain injury and/or repeat head blows. Keywords: optical coherence tomography, OCT, mild traumatic brain injury, macula, retinal nerve fiber layer, imaging, concussion, eye, biomarkers, chronic traumatic encephalopathy, CTE
