Response time and response time variability as indicators of response quality during static automated perimetry

PURPOSE: Perimetry is a both demanding and strenuous examination method that is often accompanied by signs of fatigue, leading to false responses and thus incorrect results. Therefore, it is essential to monitor the response quality. The purpose of this study was to evaluate the response time (RT) and its variability (RTV) as quality indicators during static automated perimetry. METHODS: Size III Goldmann stimuli (25.7′) were shown with the OCTOPUS 900 perimeter in four visual field locations with 13 different stimulus luminance levels (0.04–160 cd/m(2)). An increased rate of false-positive and false-negative catch trials (25% each) served to monitor the response quality simultaneously together with response time recording. Data evaluation was divided into global and individual analysis. For global analysis, the agreement indices (AI, agreement between time periods with an increased number of false responses to catch trials and time periods with pathological response to time-based values set into relation to time periods in which only one of the two criteria was considered pathological) and for individual analysis, the Spearman correlation coefficients were calculated. Ophthalmologically normal subjects with a visual acuity ≥ 0.8, and a maximum spherical/cylindrical ametropia of ± 8.00/2.50 dpt were included. RESULTS: Forty-eight subjects (18 males, 30 females, age 22–78 years) were examined. The total number of false responses to catch trials was (median/maximum): 6/82. RT and RTV were compared to the occurrence of incorrect responses to catch trials. The resulting individual Spearman correlation coefficients (median/maximum) were for RT: ρ(RT) = 0.05/0.35 and for RTV: ρ(RTV) = 0.27/0.61. The global analysis of the RTV showed agreement indices (median/maximum) of AI(RTV) = 0.14/0.47. CONCLUSIONS: According to this study, an increased portion of catch trials is suitable as a verification tool for possible response quality indicators. The RTV is a promising parameter for indicating the response quality. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s00417-021-05349-z.