King-Devick and Pre-season Visual Function in Adolescent Athletes

Abstract

Purpose The King-Devick Test (KD) has been studied as a remove-from-play sideline test in college-age athletes and older; however, studies in younger athletes are limited. A cross-sectional study of the KD and other vision correlates was completed on school-aged athletes during pre-season physicals for a variety of sports to determine the repeatability of the KD. The study also evaluated how convergence, alignment, or pupil function contributed to a slower King-Devick baseline reading. Methods 785 athletes underwent vision screenings in a hospital or school setting by trained/certified staff as part of pre-season physicals. 619 had KD testing completed per the manufacturer’s suggested protocol and repeated. Other baseline vision testing included visual acuity, Modified Thorington testing for alignment, convergence testing, and pupil function using the NeurOptics (NPI-200) NPi. Results The mean fastest, error-minimized KD time for all participants was 43.9 seconds(s) (sd±11.6, range 24–120). Median KD time got faster (+) with age (p <.0001). The inter-class correlation coefficient for all scores was 0.92. The absolute mean time difference for any two tests was 3.5s (sd±2.5, range 0–23). There was no association between the best KD time and reduced NPC (p=0.63), Modified Thorington measure of alignment (p = 0.55), or NPi pupil function (p=0.79). The Bland Altman repeated measure limits of agreement was ±6.5s for those in the 10th–12th grades, and ±10.2s for those in 6th–9th grades. Conclusions King-Devick score in junior high and high-school athletes is variable but gets faster and more repeatable with increasing age. The KD does not correlate significantly with reduced convergence, alignment, or pupil function. Based on grouped data, a slowing of 10 seconds for younger athletes and 6 seconds for older athletes on a second administration represents a true difference in testing speed. Within-player variability should be considered when removal-from-play decisions are influenced by KD results.

Disparities on Baseline Performance Using Neurocognitive and Oculomotor Clinical Measures of Concussion

“…As literature on the KD test continues to quickly surface, these results provide new sociodemographic findings. These results are in slight contrast to those of Weise et al, 47 in which differences in race on the KD test were noted in a large sample of high school athletes that included a large cohort of Black/ African Amerian athletes (n = 346). This study found that White athletes had faster times than Black/African American athletes among those 10 to 18 years of age; however, SES was not considered.…”

“…However, school attendance did not account for a measure of SES. 47 Overall, there is a critical need to determine if there are performance disparities on clinical concussion measures based on race and SES. The majority of preceding studies have primarily focused on collegiate populations and therefore neglected to explore the effects of race and SES in an adolescent-aged population.…”

The King-Devick test in an outpatient concussion clinic: Assessing the diagnostic and prognostic value of a vision test in conjunction with exercise testing among acutely concussed adolescents

“…Moran et al [43] found that healthy athletes aged 8-11 had slower KD test times and more errors than individuals aged 12-14 years (p < 0.001). Weise et al [44] showed that KD scores improved with age in junior high and high school athletes and that they were highly variable within these age groups. Alsalaheen et al [45] showed that 16 to 18 year old athletes achieved faster KD times than 13 to 15 year old athletes whereas Anderson et al [46] and Benedict et al [47] showed that KD test scores become worse with age in adults (mean age 40.5 and 36 years, respectively).…”

The role of pre-season health characteristics as injury risk factors in female adolescent soccer players

“…Data was collected before and after a competitive season of 15 games over ten weeks. The researchers first obtained anthropometric data, including height and weight; followed by the K-D test performed according to manufacturer’s recommended guidelines 21 , 22 , 23 ) . The K-D test required the participants to read a series of numbers from three separate cards as fast as possible without errors.…”