Minimum perceptual time (MPT). Repeatability and reproducibility of variables applied to "sports vision"

"Minimum Perceptual Time" (MPT) is the ability to take the most visual information in the least time. The purpose of the study was to assess intraobserver and interobserver repeatability of a MPT measurement method by using COI-SV^® software and to analyze the possible influence of age and sex.

MPT was measured in 79 participants by using COI-SV^® software. Visual acuity was 20/80 (2.50 m) and numbers were gradually increasing in quantity and decreasing in exposure time. The most quantity of numbers and the least time was written down. To assess intraobserver and interobserver repeatability, a protocol based on repeating the test 4 times (2 intrasession and 2 intersessions with 2 examinators) was established. Comparison of means and Spearman correlation were performed to evaluate the influence of sex and age. It was investigated inter and intraexaminer variability using repeatability indices, as well as Bland-Altman analysis to define limits of agreement.

A total of 79 participants were included (mean age 32.8 ± 11.95 years, range 19-64 years). Regarding sex, there were no significant differences between men and women (p = 0.080), whereas age and MPT had an inverse correlation (p = 0.01). Interexaminer and intraexaminer repeatability proved to be moderate to good in all methods. Bland-Altman showed difference between sessions was 0.259 ± 2.189 (-4.030 and + 4.549) and difference between examiners was - 0.519 ± 2.104 (-4.642 and + 3.604).

MPT measurements with COI-SV^® software evidenced moderate to good repeatability and observers` independent result, so it could be included in optometric examinations.

WHAT IS KNOWN : Sports optometry is a relatively new field, so research is scarce and of poor quality. The scarcity of literature is practically limited to studies in the field of psychology, although they do not provide us with much information since they have not been studied for the mentioned field. The in-depth study of new standardized measurement methods would be of great help for optometrists in their clinical practice.

This study is the first to determine intraobserver and interobserver repeatability and reproducibility for Minimum Perceptual Time (MPT) measurements acquired by the COI-SV® software, exhibiting ICC > 0.7 and establishing limits of agreement by using Bland-Altman analysis. In a significant way, MPT and age would have an inverse correlation, whereas MPT results would be better in men than women. Our results add evidence towards validating the test included in COI-SV® software so that the optometrist can include it in their clinical protocols in order to obtain more complete information on visual examinations.