Diagnostic power of multifocal objective perimetry in concussion.

Abstract

Purpose : To compare the diagnostic power of two variants of multifocal pupillographic objective perimetry (mfPOP) in mild sports-related concussion.

Methods : We tested 22 persons who had their concussion within 3 to 41 days (15.4 ± 13.6 days, mean ± SD), and 23 subjects who had their concussion within 69 to 2961 days (941.5 ± 769.0 days). We refer to these as the Acute and Chronic patient groups. All but two of the subjects were males, mostly rugby players aged 22.4 ± 3.06 y. Concussion was judged by an accredited sports physiologist/physiotherapist on the field of play, where the person was asked to leave the field for a day, usually without having lost consciousness. Control subjects comprised either 14 male rugby players who claimed never to have been concussed (22.3 ± 2.37 y), or 17 male non-athlete controls (22.3 ± 3.8 y). The two mfPOP tests were an older 4th-generation method called P129, and the W12 5th-generation test. Both tests were done with an objectiveFIELD Analyser (OFA) by Konan Medical USA. P129 tests 44 regions of each eye in 7 minutes, and W12 tests 12 regions/eye in < 90 seconds. Both multifocal stimulus arrays respected the vertical and horizontal meridians and covered ± 30 degrees of the central visual field. Diagnostic power was assessed by area under receiver operating characteristic plots (AUROC) and standardised effect size as measured by Hedge’s g. The combined sensitivity and delay data we used examined discrimination for the mean of the worst 6 regions in each eye of the study group and each of the two control groups.

Results : Outcomes depended upon which control group was used: athletes (Table A) or non-athletes (Table B). When athlete controls were used, AUROC and g-values were small for chronic patients, 65.1 ± 6.98 and 0.32 respectively, for the W12 test. When non-athlete controls were used, diagnostic power for chronic patients was the highest, reaching 82.6 ± 5.19 and 1.44 for W12.

Conclusions : The difference in diagnostic performance when athlete and non-athlete controls were used implied that even the athletes with no self-reported concussion had some issues. Given speed of the W12 test and its ability to detect acute concussion the W12 test may be clinically useful for on-field assessments.