Study Stopped
During a piloting phase with our staff, the technology/eye-tracking device did not collect outcomes as expected.
Eye Tracking as a Biomarker of Cannabis Effects
1 other identifier
interventional
1
1 country
1
Brief Summary
Biomarkers of recent drug use and intoxication have societal relevance, in that they are used by law enforcement and other agencies to detect drug impairment. For instance, a breathalyzer can quickly and accurately detect blood alcohol content (BAC) to indicate if a person is under the influence of alcohol; however, there is currently no similar way to quickly detect if a person is under the influence of cannabis. In light of increasing cannabis use, it is important to define a quantitative, objective method of determining recent use and intoxication. The link between changes in eye characteristics (e.g. movement, pupil dilation) and cannabis use is documented (Peragallo et al. 2013), but insufficiently characterized. Certain outcomes of eye behavior are known to be affected by recent cannabis use (e.g. the eyes' ability to converge on a target; Stapleton et al 1986), while findings are mixed regarding other outcomes (e.g. the eyes' ability to smoothly follow a target; Fant et al. 1998). Thus, the goal of this study is to identify a characteristic pattern of eye behavior, defined by performance on a battery of four eye tasks, as a function of recent cannabis use (7% vs. 0% THC). Using 30 healthy cannabis users (15 men, 15 women), this study will be one of the first to assess changes in eye behavior as a function of recent cannabis use within a quantified virtual reality (VR) environment. This study will examine the effect of smoked cannabis (7% vs. 0% THC) on individual eye movements, with the goal of defining the utility of the eyes as potential objective indicators of cannabis use and intoxication. Four eye tests (nystagmus, smooth pursuit, convergence, and pupillary light response; outlined below), which previous literature has defined as effective in detecting recent drug use (including opioids and alcohol; Murillo et al. 2004), have been compiled into a 5-minute task battery using a VR headset environment equipped with high frequency infrared eye trackers (the HTC Vive with Pupil Labs Tracking). This 5-minute VR battery of four eye tests will be administered prior to cannabis consumption as a baseline, and then at 0, 15, 30, 45, 60, 75, 90, 105, 120, and 165 min after cannabis, with the goal of comparing baseline values to the ten post-cannabis timepoints to detect changes in eye behavior as a function of cannabis intoxication. The study will also utilize a battery of subjective-effects and mood visual analogue scales (0-100 mm; e.g. 'Good Drug Effect') prior to the eye test battery at each timepoint, allowing us to correlate each outcome of the eye tasks to subjectively reported cannabis impairment and mood. In addition to measuring eye behavior as a function of cannabis use, the training session of this study will be used to also collect exploratory data on the relationship between pupil dilation and experimental pain. Using Quantitative Sensory Testing (Medoc TSA-II NeuroSensory Analyzer), thermal pain threshold and tolerance will be induced using a cold stimulus (4.0°C; induced with a 30 x 30 mm Peltier thermode, which is 1.5" square metal applicator that is connected to the TSA-II NeuroSensory Analyzer device and software, and produces an ongoing cold sensation applied to the lower palm of the participant's non-dominant hand). Participants will indicate first feelings of pain (pain threshold), and when the pain becomes too much to bear (pain tolerance) by pressing a button on a controller connected to the TSA-II. Throughout exposure to the cold stimulus, changes in pupil size to the patient's subjectively reported pain latencies will be recorded.
Trial Health
Trial Health Score
Automated assessment based on enrollment pace, timeline, and geographic reach
participants targeted
Target at below P25 for phase_2
Started Oct 2019
Shorter than P25 for phase_2
1 active site
Health score is calculated from publicly available data and should be used for screening purposes only.
Trial Relationships
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Study Timeline
Key milestones and dates
First Submitted
Initial submission to the registry
September 19, 2019
CompletedFirst Posted
Study publicly available on registry
September 24, 2019
CompletedStudy Start
First participant enrolled
October 1, 2019
CompletedPrimary Completion
Last participant's last visit for primary outcome
December 30, 2019
CompletedStudy Completion
Last participant's last visit for all outcomes
January 31, 2020
CompletedResults Posted
Study results publicly available
June 30, 2022
CompletedJune 30, 2022
June 1, 2022
3 months
September 19, 2019
May 31, 2022
June 29, 2022
Conditions
Outcome Measures
Primary Outcomes (1)
Convergence
Using a Virtual Reality headset, a stimulus (a fixation cross) moves from 12 inches to 2 inches away from the participant's nose at a continuous speed over 5 seconds, then is held at that point for 10 seconds. The accuracy with which the participant completes this task will be measured by comparing pupil position with the target position within the virtual reality environment, down to the millimeter. Speed will also be assessed by measuring pupil position as a function of target fixation, down to the millisecond.
% Change from baseline during each of two sessions (measurements taken at baseline, 0, 15, 30, 45, 60, 75, 90, 105, 120, and 165 minutes post-cannabis)
Study Arms (2)
Active Cannabis
EXPERIMENTALIn this session, the participant will smoke two-thirds of one active cannabis cigarette (7% THC) according to our paced-puff procedure (Foltin et al. 1987). They will complete an eye task battery (5 minutes per battery) 15 minutes prior to smoking as a baseline measure in each session, and again at the following timepoints: 0, 15, 30, 45, 60, 75, 90, 105, 120, and 165 minutes post-cannabis. Baseline assessments will be compared to those at post-cannabis timepoints.
Placebo Cannabis
PLACEBO COMPARATORIn this session, the participant will smoke two-thirds of one inactive placebo cannabis cigarette (0% THC) according to our paced-puff procedure (Foltin et al. 1987). They will complete an eye task battery (5 minutes per battery) 15 minutes prior to smoking as a baseline measure in each session, and again at the following timepoints: 0, 15, 30, 45, 60, 75, 90, 105, 120, and 165 minutes post-cannabis. Baseline assessments will be compared to those at post-cannabis timepoints.
Interventions
Smoked active cannabis (7% THC) vs. placebo inactive cannabis (0% THC)
Eligibility Criteria
You may qualify if:
- Males/non-pregnant females
- Report smoking cannabis ≥1 day per week
- Able to perform all study procedures
You may not qualify if:
- Meeting DSM-V criteria for severe substance use
- Use of illicit drugs ≥1 day/week in the prior 4 weeks
- Abnormality with the eyes which may affect the eye tracking technology such as color blindness, naturally occurring nystagmus, amblyopia, strabismus, age-related macular degeneration (AMD), cataract, diabetic eye disease, glaucoma, dry eye, extreme refractive error, bacterial or viral infections of the eye
- \. User of supplemental oxygen
Contact the study team to confirm eligibility.
Sponsors & Collaborators
Study Sites (1)
New York State Psychiatric Institute
New York, New York, 10032, United States
MeSH Terms
Conditions
Interventions
Condition Hierarchy (Ancestors)
Results Point of Contact
- Title
- Caroline A Arout, PhD
- Organization
- New York State Psychiatric Institute
Publication Agreements
- PI is Sponsor Employee
- Yes
Study Design
- Study Type
- interventional
- Phase
- phase 2
- Allocation
- RANDOMIZED
- Masking
- TRIPLE
- Who Masked
- PARTICIPANT, INVESTIGATOR, OUTCOMES ASSESSOR
- Purpose
- BASIC SCIENCE
- Intervention Model
- CROSSOVER
- Sponsor Type
- OTHER
- Responsible Party
- PRINCIPAL INVESTIGATOR
- PI Title
- Assistant Professor of Neurobiology
Study Record Dates
First Submitted
September 19, 2019
First Posted
September 24, 2019
Study Start
October 1, 2019
Primary Completion
December 30, 2019
Study Completion
January 31, 2020
Last Updated
June 30, 2022
Results First Posted
June 30, 2022
Record last verified: 2022-06