Visual Structure and Function of Athletes in Collision Sports
Journal of Neuro-Ophthalmology
Published online Sept. 6, 2017
Vision-based measures are known markers for Alzheimer disease, multiple sclerosis, and Parkinson disease, and they may aid in understanding associations between repetitive head trauma and neurodegenerative sequelae. In a comparison study of athletes in collision sports and matched controls, Leong et al. noted substantial retinal axonal and neuronal loss in the athletes, along with reduced visual function and quality of life (QOL). Patterns were similar to those of the above-mentioned neurologic diseases.
In their cross-sectional study, the authors compared 46 professional athletes (active or retired) with 104 age/race-matched healthy controls who had not participated in collision sports. All study participants received spectral-domain optical coherence tomography (SD-OCT) to measure thickness of the peripapillary retinal nerve fiber layer (RNFL) and the macular ganglion cell complex. High-contrast visual acuity (100% level) and low-contrast letter acuity (1.25% and 2.5% levels) were determined, and the King-Devick test of rapid number naming was administered. Vision-specific measures of QOL also were assessed.
On average, the RNFL of athletes (14 boxers, 29 football players, and 3 ice hockey players) was 4.8 μm thinner than that of controls. RNFL thinning was highest for boxers (10.8 μm vs. controls). Binocular and monocular low-contrast letter acuity at 2.5% contrast, as well as vision-specific QOL, differed significantly between athletes and controls. Performance time for rapid number naming was similar for the study groups.
Trauma-related vision changes that are detectable in vivo represent a unique opportunity to study related mechanisms of neurodegeneration. In future research, the authors plan to assess fluid biomarkers and apply imaging and cognitive measures of evaluation. Longitudinal examination will help determine whether structural and functional deficiencies signal neurodegeneration. Such knowledge will be important for establishing outcome measures in trials of drugs that target neuroprotection.
The original article can be found here.