Abstract
Purpose :
To determine the prevalence and nature of binocular vision deficits post-concussion in the pediatric and adolescent population.
Methods :
Medical records of patients examined in the multidisciplinary brain injury clinic from July 2014 to October 2015 were retrospectively reviewed. Each patient received a comprehensive eye examination including cycloplegic retinoscopy and binocular vision tests to assess vergence, accommodation and tracking.
Results :
Records of 45 patients with visual acuity 20/25 or better in each eye (mean age: 15 years ±3.3; 25 were females) were reviewed. First-time concussion was reported in 55% of patients, and 45% had two or more concussions. Patients were seen at the clinic within about 1 to 50 months (median: 3.9) of their last concussion. Frequently reported visual symptoms included increase in headache with close work, difficulty focusing, intermittent blurry vision and light sensitivity. The median refractive error was 0.50 D (range: -5.5 to 1.25); 33/45 patients were hyperopic (0.75 D; range:0.25 to 1.25), 10/45 were myopic (-0.75 D; range:-0.25 to -5.5) and 2/45 were emmetropic. Binocular vision deficits were diagnosed in 87% of patients, of which 22% had an accommodative disorder, 22% had a vergence disorder, and 40% had both. Of the binocular vision assessment tests, near point of convergence (10.6 cm ± 4.1), positive fusional vergence (PFV) for distance (14.1 PD ± 5.7) and near (25.8 PD ± 14.8), vergence facility (12.9 cpm ± 5.9), monocular accommodation facility (6.6 cpm ±3.9), and monocular accommodation amplitudes (8.6 D ±2.2) were abnormal when compared to the normative control data reported in the literature (p<0.05). Of these tests, monocular accommodative facility test was the most discerning. Three out of four patients (34/45) demonstrated difficulty with the test. Of the 34 patients, 31 had difficulty clearing the plus lens, suggesting a deficit in relaxing accommodation.
Conclusions :
This data shows a high prevalence of binocular vision deficits in chronically symptomatic post-concussion patients. These deficits appear both in the accommodative and vergence systems. Interestingly, difficulty relaxing accommodation was the most common clinical finding. Understanding the nature of these deficits provides a starting point to determine treatment methods that would potentially shorten the duration of symptoms.
This is an abstract that was submitted for the 2016 ARVO Annual Meeting, held in Seattle, Wash., May 1-5, 2016.