A traumatic brain injury (TBI) can adversely affect a patient’s visual function, and new research is helping us understand exactly how. Researchers recently found that TBI patients tend to have deficits in accommodation and stereopsis.

The team measured the refractive status, stereoacuity and accommodative ability of 22 TBI patients and 22 controls. They discovered that patients who had suffered a TBI were significantly more symptomatic than controls. They noted that near stereoacuity thresholds were significantly higher and accommodative amplitude and facility rates were significantly lower in TBI patients.

They added that patients with a TBI showed no significant difference between the accommodative facility rates of the pre‐ and post‐three‐minute binocular flipper sessions. These patients had a greater accommodative lag to the 2.5D, 3.0D, 4.0D and 5.0D stimuli but not to the 2.0D stimulus. The investigators observed a steeper regression equation of accommodative lag to stimuli in the TBI group.

The study authors concluded that there was a significant correlation between visual symptoms and clinical findings in TBI patients, including binocular accommodative amplitude, binocular accommodative facility and stereopsis.

Chen N, Liao M, Yang C, et al. Accommodation and stereopsis in adults with traumatic brain injury. Clin Exp Optom. March 12, 2020. [Epub ahead of print].