Contrast Sensitivity and Night Driving in Older People: Quantifying the Relationship Between Visual Acuity, Contrast Sensitivity, and Hazard Detection Distance in a Night-Time Driving Simulator

Purpose(i) To assess how well contrast sensitivity (CS) predicts night-time hazard detection distance (a key component of night driving ability), in normally sighted older drivers, relative to a conventional measure of high contrast visual acuity (VA); (ii) To evaluate whether CS can be accurately quantified within a night driving simulator.Materials and MethodsParticipants were 15 (five female) ophthalmologically healthy adults, aged 55–81 years. CS was measured in a driving simulator using Landolt Cs, presented under static or dynamic driving conditions, and with or without glare. In the dynamic driving conditions, the participant was asked to simultaneously maintain a (virtual) speed of 60 km/h on a country road. In the with glare conditions, two calibrated LED arrays, moved by cable robots, simulated the trajectories and luminance characteristics of the (low beam) headlights of an approaching car. For comparison, CS was also measured clinically (with and without glare) using a Optovist I instrument (Vistec Inc., Olching, Germany). Visual acuity (VA) thresholds were also assessed at high and low contrast using the Freiburg Visual Acuity Test (FrACT) under photopic conditions. As a measure of driving performance, median hazard detection distance (MHDD) was computed, in meters, across three kinds of simulated obstacles of varying contrast.ResultsContrast sensitivity and low contrast VA were both significantly associated with driving performance (both P < 0.01), whereas conventional high contrast acuity was not (P = 0.10). There was good correlation (P < 0.01) between CS measured in the driving simulator and a conventional clinical instrument (Optovist I). As expected, CS was shown to decrease in the presence of glare, in dynamic driving conditions, and as a function of age (all P < 0.01).ConclusionContrast sensitivity and low contrast VA predict night-time hazard detection ability in a manner that conventional high contrast VA does not. Either may therefore provide a useful metric for assessing fitness to drive at night, particularly in older individuals. CS measurements can be made within a driving simulator, and the data are in good agreement with conventional clinical methods (Optovist I)

Treatment With Erythropoietin for Patients With Optic Neuritis: Long-term Follow-up.

BACKGROUND AND OBJECTIVE Erythropoietin (EPO) is a candidate neuroprotective drug. We assessed its long-term safety and efficacy as an adjunct to methylprednisolone in patients with optic neuritis and focused on conversions to multiple sclerosis (MS). METHODS The TONE trial randomized 108 patients with acute optic neuritis but without previously known MS to either 33,000 IU EPO or placebo in conjunction with 1,000 mg methylprednisolone daily for 3 days. After reaching the primary end point at 6 months, we conducted an open-label follow-up 2 years after randomization. RESULTS The follow-up was attended by 83 of 103 initially analyzed patients (81%). There were no previously unreported adverse events. The adjusted treatment difference of peripapillary retinal nerve fiber layer atrophy in relation to the fellow eye at baseline was 1.27 µm (95% CI -6.45 to 8.98, p = 0.74). The adjusted treatment difference in low-contrast letter acuity was 2.87 on the 2.5% Sloan chart score (95% CI -7.92 to 13.65). Vision-related quality of life was similar in both treatment arms (National Eye Institute Visual Functioning Questionnaire median score [IQR]: 94.0 [88.0 to 96.9] in the EPO and 93.4 [89.5 to 97.4] in the placebo group). The rate of multiple sclerosis-free survival was 38% in the placebo and 53% in the EPO group (hazard ratio: 1.67, 95% CI 0.96 to 2.88, p = 0.068). DISCUSSION In line with the results at 6 months, we found neither structural nor functional benefits in the visual system of patients with optic neuritis as a clinically isolated syndrome, 2 years after EPO administration. Although there were fewer early conversions to MS in the EPO group, the difference across the 2-year window was not statistically significant. CLASSIFICATION OF EVIDENCE This study provides Class II evidence that for patients with acute optic neuritis, EPO as an adjunct to methylprednisolone is well tolerated and does not improve long-term visual outcomes. TRIAL REGISTRATION INFORMATION The trial was preregistered before commencement at clinicaltrials.gov (NCT01962571)

Parameters for Vigilance, Attention and Cognitive Workload within Eye Tracking Recordings

Purpose: Usually, a theory of attention upon gazed-at locations is applied. More parameters than gaze location can be derived to improve the theory of attention allocation. The aim of this study was to identify parameters related to eye tracking, that are suitable indicators of attention. Methods: Binocular eye tracking data was collected with the Eye Tribe tracking system (The Eye Tribe Aps, Copenhagen, Denmark) for the task of visual exploration of the painting “Unexpected Visitors” by Ilya Repin. 20 subjects (valid data: 19/20) had to look at this painting for about two and a half minutes in order to generate fatigue and inattention. In a second step, suitable parameters of attention were transferred to a data set (8 subjects, valid data: 6/8) on a perimetric task executed with the OCTOPUS 900 perimeter (Haag-Streit, Köniz, Switzerland). Monocular parameters could be applied on the perimetric task, the error rate (false positive and false negative catch trials, 5 % each) were taken as additional parameter. Results: For the image viewing task, the only parameter showing significance was the average level (a10) of fatigue waves (p = 0.00024, ANOVA, ∆ = -0.8316 px). Blink duration (∆ =-270.4 ms), pupil variability (∆ = -0.17868), saccade length (∆ =-0.3135 px) and fixation duration (∆ = 186.5 ms) did not change significantly, but showed relevant trends by differences ∆ of their median between the first and last tenth of the recording time. Blink rate and the Index of Cognitive Activity (ICA) did neither show significant changes nor relevant trends. Vergence accuracy failed to indicate fatigue due to variability between subjects and comparatively small effect size. For the perimetric data, in 3 of 6 subjects fatigue waves over a limited time window could be observed. Only for one subject, a relevant increase in false negative responses to catch trials (50 percentage points) could be observed. Conclusion: Pupil diameter variability, saccade length, fixation duration and fatigue waves were the parameters indicating fatigue. Only the latter parameter has the potential to be applied to perimetric data.Ziel: Aufmerksamkeit lässt sich nicht nur anhand von Blickzuwendungen beschreiben. Deutlich mehr Parameter können abgeleitet werden, um die Theorie der Aufmerksamkeitszuwendung zu verbessern. Diese Masterarbeit zielt auf die Identifikation von Parametern, die bei Eye Tracking Experimenten aufgezeichnet, aber teils nur selten ausgewertet werden, ab. Methode: Bildbetrachtungsdaten für das Gemälde „Unexpected Visitors“ von Ilya Repin wurden mit einem binokularen Eye Tracker (The Eye Tribe Aps, Kopenhagen, Dänemark) bei 20 Probanden (gültige Daten: 19/20) für einen Zeitraum von zweieinhalb Minuten aufgenommen. Geeignete Parameter wurden auf einen Datensatz zur Perimetrie (8 Probanden, gültige Daten: 6/8), aufgenommen mit einem OCTOPUS 900 Perimeter (Haag-Streit, Köniz, Schweiz), transferiert. Die Fehlerrate (falsch positive/falsch negative Fangfragen, je 5 %) wurde eruiert. Ergebnisse: Aufmerksamkeits-Indikatoren zeigten signifikante Werte für Schläfrigkeitswellen (Average-Level 10, p = 0.00024, ANOVA, ∆ = -0.8316 px). Pupillenvariabilität (∆ = -0.17868), Saccadenlänge (∆ = -0.3135 px), Fixationsdauer (∆ = 186.5 ms) und Lidschlussdauer (∆ = -270.4 ms) zeigten keine signifikanten Änderungen, jedoch waren relevante Trends zu sehen, da die Mediane des jeweils ersten und letzten Zehntels der Aufnahmen sich um den Differenzbetrag ∆ unterschieden. Die Lidschlussfrequenz und der Index kognitiver Aktivität zeigten keine relevanten Trends. Die Vergenzgenauigkeit eignete sich aufgrund zu hoher Variabilität und zu geringer Effektgröße ebenfalls nicht als Indikator. Während der perimetrischen Untersuchung konnten nur bei 3 von 6 Probanden zeitlich begrenzte Schläfrigkeitswellen festgestellt werden. Nur ein Proband zeigte mit dem Einsetzen von Müdigkeit einen relevanten Anstieg falsch negativer Antworten auf Fangfragen (50 Prozentpunkte). Fazit: Aufmerksamkeits-Indikatoren sind Pupillenvariabilität, Saccadenlänge, Fixationsdauer und Schläfrigkeitswellen. Lediglich der letztgenannte Parameter kann potenziell auf perimetrische Daten übertragen werden

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