Diagnosis of vergence and accommodation deficits in children and adolescent with concussion using established clinical criteria versus normative data.

Abstract

Purpose : Previous studies have established that convergence insufficiency and accommodative dysfunction are diagnosed more frequently following concussion as compared to the general population. However, conclussions are limited due to inconsistent diagnostic criteria and a lack of non-concussed control data. We compare the frequency of vergence deficits (VD, i.e., convergence insufficiency, convergence excess, and fusional vergence deficit) and accommodation deficits (AD) in concussed individuals to control participants using both established clinical criteria (ECC) and the distribution of normal clinical data.

Methods : Retrospective cohort study at Boston Children’s Hospital. Non-concussed control group: n = 30 (median age: 9.2 years, IQR: 8.1 -10.6.), evaluated in 2016, Concussed group: n = 256 (median age: 15.2 years, IQR: 13.6 -16.8) evaluated from 2012 to 2020. Both groups had visual acuity 20/30 or better in each eye; complete clinical assessment of vergence and accommodation; no strabismus, amblyopia, or other ocular pathology. Normal accommodation was determined by Hofstetter’s formula (15-0.25*age). VD and AD were identified using both of the following methods: 1) ECC and 2) clinical findings falling outside the 95^th percentile of control group criteria (CGC). Fischer’s exact test and Chi-square Test assessed group differences.

Results : In the ECC in control data, 67% failed near point of convergence (NPC) (≥ 6 cms) and 33% failed monocular accommodative facility (MAF) (≥ 6 cycles per minute (cpm)). There was a difference in frequency of AD (33 vs 13%, p=0.02), but no change in VD (7 vs 7%, p>0.05) between ECC vs CGC respectively in controls. In the concussed group, the failure rate was higher for NPC (79 vs 52%, p=0.001), convergence amplitude (48 vs 59%, p<0.01) and MAF (64 vs 35%, p<0.001) using ECC vs CGC respectively. There was a difference in frequency of AD (81 vs 72%, p=0.015), but no change in VD (51 vs 50%) between ECC and CGC respectively in the concussed group.

Conclusions : We found using ECC for NPC ≥ 6 cm and accommodative facility ≥ 6 cpm resulted in higher failure rates in the control and concussed groups than would be expected. The differences between ECC and CGC emphasize the need for a larger sample of normative data and careful consideration of criteria used for diagnosis of visual deficits in concussion.

This is a 2021 ARVO Annual Meeting abstract.