Use of the King-Devick Variable Color Contrast Sensitivity Chart to differentiate stages of age-related macular degeneration.

OBJECTIVE: This study aimed to determine which colour contrast sensitivity differences exist in early to advanced age-related macular degeneration (AMD) and examine the potential utility of the King-Devick Variable Color Contrast Sensitivity Chart in detecting AMD severity. METHODS AND ANALYSIS: A total of 85 participants (144 total eyes) were recruited from multiple clinical practices and enrolled in the study. The control group consisted of 57 healthy eyes. The non-exudative AMD (NE-AMD) group consisted of 45 eyes. The exudative AMD (E-AMD) group consisted of 42 eyes. In a single study visit, monocular best-corrected visual acuity (BCVA) at 40 cm with 100% black contrast was determined for each eye. Using the BCVA line, the number of letters correctly identified (out of 10) was recorded for various colour presentations (red, green, blue and yellow) and at decreasing contrast levels (100%, 75%, 50% and 25%). RESULTS: Our results show worse visual performance under various colour contrast settings in E-AMD patients compared with healthy controls and NE-AMD. Colour contrast performance using blue and yellow differentiated more advanced stages of disease in E-AMD from earlier NE-AMD disease. Blue and black colour contrast performance more accurately identified the E-AMD group from healthy controls and the NE-AMD group. CONCLUSION: The findings of this study demonstrate that colour contrast, particularly with black, blue and yellow, is impaired in E-AMD suggesting the potential for colour contrast measures to serve as an adjunctive clinical tool in identifying subtle altered visual function as well as the potential for detecting disease severity.

Visual Structure and Function in Collision Sport Athletes.

BACKGROUND: Vision-based measures have been shown to be useful markers in multiple sclerosis (MS), Alzheimer and Parkinson disease. Therefore, these testing paradigms may have applications to populations explaining repetitive head trauma that has been associated with long-term neurodegenerative sequelae. We investigated retinal structure and visual function in professional collision sport athletes compared to age- and race-matched control participants. METHODS: In this cross-sectional study, participants underwent spectral-domain optical coherence tomography (OCT) measurements of peripapillary retinal nerve fiber layer (RNFL) and macular ganglion cell complex (GCC = ganglion cell + inner plexiform layers) thickness. High-contrast visual acuity (100% level), low-contrast letter acuity (LCLA) (1.25% and 2.5% levels), and King-Devick Test of rapid number naming performance were administered. Vision-specific quality of life (QOL) measures were assessed. RESULTS: Among 46 collision sport athletes (boxing, n = 14; football, n = 29; ice hockey, n = 3) and 104 control participants, average RNFL thickness was a significant predictor of athlete vs control status with athletes demonstrating 4.8-µm of thinning compared to controls (P = 0.01, generalized estimating equation [GEE] models accounting for age and within-subject, intereye correlations). Athlete vs control status was not a predictor of RNFL thickness for the subgroup of football players in this cohort (P = 0.60). Binocular (P = 0.001) and monocular (P = 0.02) LCLA at 2.5% contrast and vision-specific QOL (P = 0.04) were significant predictors of athlete vs control status (GEE models accounting for age and within-subject, intereye correlations). Rapid number naming performance times were not significantly different between the control and athlete groups. CONCLUSIONS: This study showed that retinal axonal and neuronal loss is present among collision sport athletes, with most notable differences seen in boxers. These findings are accompanied by reductions in visual function and QOL, similar to patterns observed in multiple sclerosis, Alzheimer and Parkinson diseases. Vision-based changes associated with head trauma exposure that have the potential to be detected in vivo represent a unique opportunity for further study to determine if these changes in collision sport athletes are predictive of future neurodegeneration.

The Effect of In-School Saccadic Training on Reading Fluency and Comprehension in First and Second Grade Students.

Efficient eye movements provide a physical foundation for proficient reading skills. We investigated the effect of in-school saccadic training on reading performance. In this cross-over design, study participants (n = 327, 165 males; mean age [SD]: 7 y 6 mo [1y 1 mo]) were randomized into treatment and control groups, who then underwent eighteen 20-minute training sessions over 5 weeks using King-Devick Reading Acceleration Program Software. Pre- and posttreatment reading assessments included fluency, comprehension, and rapid number naming performance. The treatment group had significantly greater improvement than the control group in fluency (6.2% vs 3.6%, P = .0277) and comprehension (7.5% vs 1.5%, P = .0002). The high-needs student group significantly improved in fluency ( P < .001) and comprehension ( P < .001). We hypothesize these improvements to be attributed to the repetitive practice of reading-related eye movements, shifting visuospatial attention, and visual processing. Consideration should be given to teaching the physical act of reading within the early education curriculum.

King-Devick Test identifies real-time concussion and asymptomatic concussion in youth athletes.

BACKGROUND: Sports concussion has an annual incidence of approximately 3.8 million. Over half go unreported and a substantial number may be asymptomatic. A rapid, cost-effective, and reliable tool that facilitates diagnosis of concussion is needed. The King-Devick (K-D) test is a vision-based tool of rapid number naming for assessment of concussion. In this study, we evaluated the utility of the K-D test in real time for identification of symptomatic concussion in youth athletes and to determine if similar impairment (subclinical concussion) exists in youth athletes without an obvious head injury or symptoms. METHODS: Youth hockey players underwent K-D testing preseason, postseason, and immediately after suspected concussion. Additional testing was performed in a subgroup of nonconcussed athletes immediately before and after a game to determine effects of fatigue on K-D scores. RESULTS: Among 141 players tested, 20 had clinically diagnosed concussion. All 20 had immediate postconcussion K-D times >5 seconds from baseline (average 7.3 seconds) and all but 2 had worse postseason scores (46.4 seconds vs 52.4 seconds, p < 0.05, Wilcoxon signed rank test). Nonconcussed athletes saw minimal improvement postseason (43.9 seconds vs 42.1 seconds, p < 0.05) and 51 nonconcussed players assessed before and after a game revealed no significant time change as a result of fatigue. CONCLUSIONS: Rapid number naming using the K-D test accurately identifies real-time, symptomatic concussion in youth athletes. Scores in concussed players may remain abnormal over time. Athletes should undergo preseason and postseason K-D testing, with additional evaluation real time to inform the assessment of suspected concussion. CLASSIFICATION OF EVIDENCE: This study provides Class III evidence that the K-D test accurately identifies real-time concussions in youth athletes.

Variability of the modified Balance Error Scoring System at baseline using objective and subjective balance measures.

AIM: To investigate preseason modified Balance Error Scoring System (mBESS) performance in a collegiate football cohort; to compare scores to an objective mobile balance measurement tool. MATERIALS & METHODS: Eighty-two athletes completed simultaneous balance testing using mBESS and the King-Devick Balance Test, an objective balance measurement tool. Errors on mBESS and objective measurements in the double-leg, single-leg (SS) and tandem stances were compared. RESULTS: Mean mBESS error score was 7.23 ± 4.65. The SS accounted for 74% of errors and 21% of athletes demonstrated the maximum error score. There was no significant correlation between mBESS score and objective balance score. CONCLUSION: The high variability and large number of errors in the SS raises concerns over the utility of the SS in identifying suspected concussion.

The King-Devick test of rapid number naming for concussion detection: meta-analysis and systematic review of the literature.

BACKGROUND: Vision encompasses a large component of the brain's pathways, yet is not represented in current sideline testing. OBJECTIVES: We performed a meta-analysis of published data for a vision-based test of rapid number naming (King-Devick [K-D] test). STUDIES & METHODS: Pooled and meta-analysis of 15 studies estimated preseason baseline K-D scores and sensitivity/specificity for identifying concussed versus nonconcussed control athletes. RESULT: Baseline K-D (n = 1419) showed a weighted estimate of 43.8 s (95% CI: 40.2, 47.5; I2 = 0.0%; p=0.85 - indicating very little heterogeneity). Sensitivity was 86% (96/112 concussed athletes had K-D worsening; 95% CI: 78%, 92%); specificity was 90% (181/202 controls had no worsening; 95% CI: 85%, 93%). CONCLUSION: Rapid number naming adds to sideline assessment and contributes a critical dimension of vision to sports-related concussion testing.

The King-Devick test for sideline concussion screening in collegiate football / Test de King-Devick para el screening en la banda de la conmoción cerebral en el fútbol universitario

Purpose: Sports-related concussion has received increasing attention as a result of neurologic sequelae seen among athletes, highlighting the need for a validated, rapid screening tool. The King---Devick (K---D) test requires vision, eye movements, language function and attention in order to perform and has been proposed as a promising tool for assessment of concussion. We investigated the K---D test as a sideline screening tool in a collegiate cohort to determine the effect of concussion. Methods: Athletes (n = 127, mean age 19.6 ± 1.2 years) from the Wheaton College football and men’s and women’s basketball teams underwent baseline K---D testing at pre-season physicals for the 2012---2013 season. K---D testing was administered immediately on the sidelines for football players with suspected head injury during regular games and changes compared to baseline were determined. Post-season testing was also performed to compare non-concussed athletes’ test performance. Results: Concussed athletes (n = 11) displayed sideline K---D scores that were significantly higher (worse) than baseline (36.5 ± 5.6 s vs. 31.3 ± 4.5 s, p < 0.005, Wilcoxon signed-rank test). Postseason testing demonstrated improvement of scores and was consistent with known learning effects (35.1 ± 5.2 s vs. 34.4 ± 5.0 s, p < 0.05, Wilcoxon signed-rank test). Test-retest reliability was analyzed between baseline and post-season administrations of the K---D test resulting in high levels of test-retest reliability (intraclass correlation coefficient (ICC) = 0.95 [95% Confidence Interval 0.85---1.05]). Conclusions: The data show worsening of K---D test scores following concussion further supporting utility of the K---D test as an objective, reliable and effective sideline visual screening tool to help identify athletes with concussion (AU)

Objetivo: Cada vez se presta más atención a las conmociones cerebrales relacionadas con el deporte, como resultado de las secuelas neurológicas que se han visto en los atletas, lo que incrementa la necesidad de encontrar una herramienta validada y rápida de detección diagnóstica. El test de King-Devick (K---D) abarca el análisis de la visión, movimientos oculares, función del lenguaje y atención, habiéndose propuesto como una herramienta prometedora para la evaluación de las conmociones cerebrales. Realizamos una investigación sobre el test K---D, como herramienta para usar en la banda de screening en un grupo universitario, para determinar los efectos de la conmoción cerebral. Métodos: Los atletas (n = 127, edad media 19,6 ± 1,2 años) de los equipos de fútbol y baloncesto masculino y femenino del Wheaton College se sometieron a un test K---D de referencia, durante los exámenes físicos de la temporada 2012-2013. Se realizó el test K---D de manera inmediata en la línea de banda a los jugadores de fútbol con sospecha de lesiones en la cabeza durante los partidos regulares, determinándose los cambios con respecto a los valores de referencia. También se realizaron pruebas al finalizar la temporada, para comparar el resultado de las pruebas en aquellos atletas que no habían sufrido conmoción cerebral. Resultados: Los atletas con conmoción cerebral (n = 11) mostraron unas puntuaciones K---D suplementarias que fueron significativamente superiores (peores) a las basales (36,5 ± 5,6s frente a 31,3 ± 4,5s, p < 0,005, test de los rangos con signo de Wilcoxon). La prueba al finalizar la temporada reflejó una mejora de las puntuaciones, siendo consistente con los efectos conocidos del aprendizaje (35,1 ± 5,2s frente a 34,4 ± 5,0s, p < 0,05, test de los rangos con signo de Wilcoxon). Se analizó la fiabilidad test-retest entre las realizaciones del test K---D basal y al finalizar la temporada, existiendo unos niveles elevados de fiabilidad test-retest (coeficiente de correlación intra-clase (ICC) = 0,95 [95% Intervalo de confianza 0,85 - 1,05]). Conclusiones: Los datos reflejan el empeoramiento de las puntuaciones del test K---D tras la conmoción cerebral, lo que refuerza la utilidad de dicha prueba como herramienta adicional y realizable en la banda de screening visual objetiva, fiable y efectiva, para la identificación de los atletas con conmoción cerebral (AU)

The King-Devick test for sideline concussion screening in collegiate football.

PURPOSE: Sports-related concussion has received increasing attention as a result of neurologic sequelae seen among athletes, highlighting the need for a validated, rapid screening tool. The King-Devick (K-D) test requires vision, eye movements, language function and attention in order to perform and has been proposed as a promising tool for assessment of concussion. We investigated the K-D test as a sideline screening tool in a collegiate cohort to determine the effect of concussion. METHODS: Athletes (n=127, mean age 19.6±1.2 years) from the Wheaton College football and men's and women's basketball teams underwent baseline K-D testing at pre-season physicals for the 2012-2013 season. K-D testing was administered immediately on the sidelines for football players with suspected head injury during regular games and changes compared to baseline were determined. Post-season testing was also performed to compare non-concussed athletes' test performance. RESULTS: Concussed athletes (n=11) displayed sideline K-D scores that were significantly higher (worse) than baseline (36.5±5.6s vs. 31.3±4.5s, p<0.005, Wilcoxon signed-rank test). Post-season testing demonstrated improvement of scores and was consistent with known learning effects (35.1±5.2s vs. 34.4±5.0s, p<0.05, Wilcoxon signed-rank test). Test-retest reliability was analyzed between baseline and post-season administrations of the K-D test resulting in high levels of test-retest reliability (intraclass correlation coefficient (ICC)=0.95 [95% Confidence Interval 0.85-1.05]). CONCLUSIONS: The data show worsening of K-D test scores following concussion further supporting utility of the K-D test as an objective, reliable and effective sideline visual screening tool to help identify athletes with concussion.

The effect of saccadic training on early reading fluency.

BACKGROUND: Eye movements are necessary for the physical act of reading and have been shown to relate to underlying cognitive and visuoattentional processes during reading. The purpose of this study was to determine the effect of saccadic training using the King-Devick remediation software on reading fluency. METHODS: In this prospective, single-blinded, randomized, crossover trial, a cohort of elementary students received standardized reading fluency testing pre- and posttreatment. Treatment consisted of in-school training 20 minutes per day, 3 days per week for 6 weeks. RESULTS: The treatment group had significantly higher reading fluency scores after treatment (P < .001), and posttreatment scores were significantly higher than the control group (P < .005). CONCLUSION: Saccadic training can significantly improve reading fluency. We hypothesize that this improvement in reading fluency is a result of rigorous practice of eye movements and shifting visuospatial attention, which are vital to the act of reading.