Football-Related Concussions and Head Impacts Correlate with Structural Changes in the Macula and Optic Nerve

Abstract

Purpose : To explore structural retinal and optic nerve changes after concussive and subconcussive head hits (SHH).

Methods : Three groups of college athletes from one school were assessed at pre-season, post-season, and a 4-month follow-up: Football players with a concussion history (n = 9), players without a concussion history (n = 11), and non-contact athletes (swimmers, track & field) (n = 12). Measures included optical coherence tomography (OCT), OCT angiography (OCTA), electroretinography, visual acuity testing (using Precision Vision EDTRS charts), contrast sensitivity, and structural MRI. Head impacts during the season were tracked with in-helmet accelerometers.

Results : Prior to the start of the season, football players with a concussive history demonstrated thicker tissue in the macula central subfield (CSF) (Hedge’s g (effect size) = 1.05, p = 0.02) and the retinal nerve fiber layer (RNFL) (g = 0.81, p = 0.08), relative to both other groups. Differences in macula CSF thickness were also observed at the end of the season (g = 1.03, p = 0.03) and 4-month follow-up (g = 1.12, p = 0.02). Changes in RNFL thickness were present until the end of the season and were not different from baseline by 4 months follow-up. (g = 0.93, p = 0.06). Total head impacts during the season correlated with increases in macula CSF thickness from baseline to 4-month follow-up (r = 0.53, p = 0.02). Total head impacts also correlated with increases in the foveal avascular zone area during post-season that trended toward significance (r_s = 0.42, p = 0.09). High intensity head impacts in particular correlated with increases in cup-to-disc ratio over the course of the season (r_s = 0.59, p = 0.01) and at follow-up (r_s = 0.63, p < 0.01).

Conclusions : Structural macular and optic nerve changes in football-related concussions may not be short-term. Even severe head impacts during a single season are associated with acute changes that may be more long term. These findings suggest that head trauma may have significant impact on long term visual and eye health as well as highlight the retina and optic nerve as important biomarkers for brain structure and function.

This abstract was presented at the 2023 ARVO Annual Meeting, held in New Orleans, LA, April 23-27, 2023.

 

Structural Retina Changes Associated with Concussion