Pupillary Dilation Reflex in Healthy Volunteers

NCT07746167 | Recruiting

• 1 other identifier: STUDY00001697
• Study Type: observational
• Target: 60
• Locations: 1 country
• Sites: 1

Brief Summary

This a single site, observational study that will examine how the pupil responds to neurostimulation under different conditions in healthy adults. The objective is to measure pupillary dilation reflex (PRD) in response to increasing neurostimulation intensities using the AlgometRx device.

Conditions

Healthy Participants

Outcome Measures

Primary Outcomes (1)

• Pupillary Dilation Amplitude in Response to Increasing Neurostimulation Intensity Measured by AlgometRx Infrared Pupillometer

  Pupillary dilation amplitude is defined as the maximum increase in pupil diameter from the pre-stimulus baseline, measured in millimeters (mm) using the AlgometRx infrared pupillometer. Pupil diameter is recorded before, during, and for 10 seconds following each 1-second stimulus. Amplitude is assessed at each stimulation intensity, beginning at 1.0 mA and increasing in 1 mA steps until participant perception, followed by measurements at 2 mA and 4 mA above the perception threshold, at each of three frequencies (5 Hz, 250 Hz, and 2000 Hz). Reported as the mean pupillary dilation amplitude in millimeters at each intensity and frequency combination.

  Day 1

Secondary Outcomes (5)

• Baseline Pupil Diameter Variability During the Pre-Stimulation Period Measured by AlgometRx Infrared Pupillometer

  Day 1

• Area Under the Pupillary Dilation Curve (AUC) Measured by AlgometRx Infrared Pupillometer

  Day 1

• Difference in Pupillary Dilation Amplitude Between Ambient Lighting Conditions Measured by AlgometRx Infrared Pupillometer

  Day 1

• Inter-Ocular Agreement in Pupillary Dilation Amplitude Measured by AlgometRx Binocular Handheld Attachment

  Day 1

• Percentage of Participants With Successful Simultaneous Binocular Pupillary Recording Using the AlgometRx Binocular Handheld Attachment

  Day 1

Study Arms (1)

Healthy Volunteers

Other: No intervention (observational study)

Interventions

No intervention (observational study) OTHER

No intervention

Healthy Volunteers

Eligibility Criteria

• Age: 18 Years - 60 Years
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64)
• Sampling Method: Non-Probability Sample

Study Population

This study will enroll up to 60 healthy adult volunteers between the ages of 18 and 60

You may qualify if:

• Age 18-60 years.
• In good general health (self-reported).
• Able and willing to provide written informed consent.

You may not qualify if:

• Eye pathology that prevents accurate pupillometry.
• Pregnancy (Self-Report)
• Diagnosis of autoimmune disorders.
• Diagnosis of any neuropathic disorder
• Inability to complete questionnaires.

Sponsors & Collaborators

• Children's National Research Institute: lead

Study Sites (1)

Children's National Hospital

Washington D.C., District of Columbia, 20010, United States

RECRUITING

MeSH Terms

Interventions

Observation

Intervention Hierarchy (Ancestors)

Methods; Investigative Techniques

Study Design

• Study Type: observational
• Observational Model: CASE ONLY
• Time Perspective: CROSS SECTIONAL
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Professor of Anesthesiology and Pediatrics

Study Record Dates

• First Submitted: July 27, 2026
• First Posted: August 4, 2026
• Study Start: April 29, 2026
• Primary Completion (Estimated): April 1, 2027
• Study Completion (Estimated): June 1, 2027
• Last Updated: August 4, 2026

Record last verified: 2026-07

Locations

US (1)