ABSTRACT
INTRODUCTION: Visual function deficits have been reported in adolescents following concussion. We compared vergence and accommodation deficits in paediatric and adolescent patients at a tertiary medical centre in the sub-acute (15 days to 12 weeks) and chronic (12 weeks to 1 year) phases of concussion recovery. METHODS: The study included patients aged 7 to <18 years seen between 2014 and 2021, who had a binocular vision (BV) examination conducted within 15 days and 1 year of their concussion injury. Included patients had to have 0.10 logMAR monocular best-corrected vision or better in both eyes and be wearing a habitual refractive correction. BV examinations at near included measurements of near point of convergence, convergence and divergence amplitudes, vergence facility, monocular accommodative amplitude and monocular accommodative facility. Vergence and accommodation deficits were diagnosed using established clinical criteria. Group differences were assessed using nonparametric statistics and ANCOVA modelling. RESULTS: A total of 259 patients were included with 111 in the sub-acute phase and 148 in the chronic phase of concussion recovery. There was no significant difference in the rates of vergence deficits between the two phases of concussion recovery (sub-acute = 48.6%; chronic = 49.3%). There was also no significant difference in the rates of accommodation deficits between the two phases of concussion recovery (sub-acute = 82.0%; chronic = 77.0%). CONCLUSION: Patients in both the sub-acute and chronic phases of concussion recovery exhibited a high frequency of vergence and accommodation deficits, with no significant differences between groups. Results indicate that patients exhibiting vision deficits in the sub-acute phase may not resolve without intervention, though a prospective, longitudinal study is required to test the hypothesis.
ABSTRACT
PURPOSE: Clinicians measure the near point of convergence (NPC) and the amplitude of accommodation (AA) from the spectacle plane, the bridge of the nose or the lateral canthus when assessing visual function. These values are compared to standard clinical criteria to diagnose vergence and accommodation deficits, despite varying reference points. This prospective study explored measuring relative to the spectacle plane and from the lateral canthus for NPC and monocular AA, and the resulting clinical implications of diagnosing visual deficits. METHODS: Participants were seen by a single clinician for an eye examination. NPC was measured from the forehead and the lateral canthus of the right eye. Monocular AA was measured from the brow and the lateral canthus. Differences between measurements were analysed using non-parametric statistical tests including Wilcoxon Signed Rank, as well as linear regression and a linear mixed effects model to adjust for inter-eye correlation and repeated measures. Chi-square tests were used to assess differences in rates of abnormal findings. RESULTS: Data were collected from 70 participants (53% female, median age 13 [11-15] years). On average, measuring NPC from the lateral canthus yielded a value 1.8 cm higher than measuring from the forehead. Measuring AA from the lateral canthus resulted in an average difference of 1.5 cm compared to measuring from the brow. A total of 39% and 76% of subjects failed NPC compared to clinical norms when measured from the forehead or the lateral canthus, respectively, while 7% and 40% failed AA when measured from the brow or the lateral canthus, respectively. CONCLUSION: With the variable anatomy of the eye, it is imperative to account for the measurement point when assessing visual function. Measuring from the lateral canthus greatly increased the failure rates for NPC and AA compared with measuring from the forehead and brow, respectively.
ABSTRACT
SIGNIFICANCE: The high frequency of vergence and accommodation deficits coexisting in patients with a vestibular diagnosis merits a detailed visual function examination. PURPOSE: Deficits in vergence and saccades have been reported in patients with vestibular symptomatology. We retrospectively evaluated visual function deficits in adolescents with vestibular diagnoses and concussion. METHODS: The following inclusion criteria were used: vestibular and optometric evaluations between 2014 and 2020, 6 to 22 years old, and 20/25 best-corrected vision or better. Clinical criteria assigned vestibular diagnoses and concussion diagnoses. Vestibular diagnoses included vestibular migraine, benign paroxysmal positional vertigo, and persistent postural perceptual dizziness. Visual function deficits were compared with a pediatric control group (30). Nonparametric statistics assessed differences in group distribution. RESULTS: A total of 153 patients were included: 18 had vestibular diagnoses only, 62 had vestibular diagnoses related to concussion, and 73 had concussion only. Vergence deficits were more frequent in patients with vestibular diagnoses and concussion (42%) and concussion only (34%) compared with controls (3%; all P = .02). Accommodation deficits were more frequent in patients with vestibular diagnoses only (67%), vestibular diagnoses and concussion (71%), and concussion (58%) compared with controls (13%; all P = .002). Patients with vestibular migraine and concussion (21) had more vergence deficits (62%) and accommodation insufficiency (52%) than concussion-only patients (47%, P = .02; 29%, P = .04). Patients with benign paroxysmal positional vertigo and concussion (20) had lower positive fusional vergence and failed near vergence facility (35%) more than concussion-only patients (16%; P = .03). CONCLUSIONS: Visual function deficits were observed at a high frequency in patients with a vestibular diagnosis with or without a concussion and particularly in vestibular migraine or benign paroxysmal positional vertigo. Visual function assessments may be important for patients with vestibular diagnoses.
