Reducing Pain From Retinal Laser With Vibrational Stimulation

Alleviating Panretinal Photocoagulation Associated Ocular Pain With Vibratory Stimulation

The goal of this clinical trial is to learn if Vibration Anesthesia Device works to reduce pain during retinal laser for diabetic retinopathy. The main question it aims to answer is:

Does the Vibration Anesthesia Device reduces the pain felt by patients during the laser treatment? Researchers will compare the standard method (no vibration device) to the standard method with the Vibration Anesthesia Device to see if the device works to reduce discomfort during treatment.

Eligible participants will have both eyes treated as required, one eye with the device and the other one without. Both the side that will be treated with the device in place and the first side to be treated will be decided by random sequence.

Study Overview

• Status: Not yet recruiting
• Conditions: Pain, Perioperative
• Intervention / Treatment: Device: Vibration Anesthesia Device; Procedure: Panretinal Photocoagulation

Detailed Description

Background:

Panretinal photocoagulation (PRP) is a widely used laser treatment for proliferative diabetic retinopathy (PDR). However, the associated ocular pain can make the procedure uncomfortable, leading to increased treatment visits or missed appointments. This pain is multifactorial and can be exacerbated by factors such as anxiety and hypervigilance. Traditional pain management techniques, such as regional anesthesia, are effective but invasive and carry potential complications. Oral medications have largely proven ineffective in alleviating PRP-related pain.

The Gate-Control Theory of pain posits that non-noxious stimuli can inhibit pain signals by activating A-β fibers, effectively "closing the gate" to pain transmission through A-δ and C fibers. The most relatable example is the mother rubbing a child's knee after an impact injury in the affected region. Transcutaneous electrical nerve stimulation (TENS) which utilizes the Gate-Control Theory of pain, has been shown to reduce ocular pain during PRP. However, its use raises practical concerns, including the need to carefully adjust pulse width, intensity, and frequency for effective pain relief. Additionally, some patients may find the muscular contractions or paresthesia uncomfortable. TENS is also contraindicated in individuals who are pregnant, have epilepsy, or have pacemakers. Vibratory stimulation activates cutaneous mechanoreceptors to reduce pain during intramuscular and subcutaneous injections. This technique is safer and less invasive than TENS and is therefore an ideal candidate for evaluating its effect in pain reduction during PRP. This study has the potential for an innovative concept by utilizing a vibratory device integrated within the PRP machine headrest.

Hypothesis:

Vibratory stimulation is expected to reduce ocular pain during PRP by activating cutaneous mechanoreceptors and inhibiting pain transmission, as suggested by the Gate-Control Theory. Its non-invasive nature makes it a practical alternative to traditional pain management methods, potentially enhancing patient comfort during the procedure.

Objective:

To evaluate the effectiveness of vibratory stimulation in reducing ocular pain during PRP treatments

Method:

Subjects will be recruited at a single tertiary referral center (Alberta Retina Consultants, Edmonton, Alberta). Matriculation will be established upon obtainment of consent, and patients will have the autonomy to withdraw from the study at any stage. The enrollment period will be from October 2024 to March 2025, with a total of 50 patients.

Laser settings will be tailored to each patient based on individual differences in pigmentation and tissue uptake. The threshold for treatment will be determined by observing an opacified photothermic response. For each patient, one eye will be treated without vibratory stimulation, while the contralateral eye will receive stimulation using the Blaine Labs Vibration Anesthesia Device. The assignment of which eye receives which treatment will be randomized using Python programming, ensuring a balanced allocation. To minimize variability, the time taken to perform PRP on both eyes will be kept as equal as possible. A no-treatment zone of 1 clock hour from the horizontal meridian will be maintained to avoid the long ciliary nerves. After treatment, patients will complete a validated survey based on the numeric rating scale (NRS) to assess pain levels for each eye treated.

• Study Type: Interventional
• Enrollment (Estimated): 50
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Mathieu Carrière, MD, FRCSC; Phone Number: (780) 448-1801; Email: mcarrie2@ualberta.ca

Study Locations

• Canada
  • Alberta
    • Edmonton, Alberta, Canada, T5H 0X5
      • Alberta Retina Consultant
      • Contact: Mathieu Carrière, MD, FRCSC; Phone Number: (780) 448-1801; Email: mcarrie2@ualberta.ca

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• Treatment naïve patients
• Bilateral PRP for proliferative diabetic retinopathy required
• >500 applications to each eye
• < 51 applications difference between each eye, in the superior or inferior hemisphere.

Exclusion Criteria:

• Poor pupil dilation < 5mm
• Media opacity preventing laser

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Supportive Care
• Allocation: Randomized
• Interventional Model: Crossover Assignment
• Masking: Single

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: PRP with the Vibration Anesthesia Device; Laser for PRP treatment as usual, but with the addition of the Vibration Device in one of the two eyes of a patient (The other eye receiving the same laser treatment without the device).	Device: Vibration Anesthesia Device; The intervention arm of this study is distinguished by way of the use of the Vibration Anesthesia Device; Procedure: Panretinal Photocoagulation; Laser treatment for diabetic retinopathy done in a standard fashion
Active Comparator: PRP without the Vibration Anesthesia Device; Laser for PRP treatment as usual in one of the two eyes of a patient (other eye receiving the same treatment, but with the Vibration Device).	Procedure: Panretinal Photocoagulation; Laser treatment for diabetic retinopathy done in a standard fashion

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Pain Rating Scale	Patient are enrolled on the same day as the study treatment. Patients will rate their pain sensation. They will have their first eye (left or right and with or without the Anesthesia Vibration Device based on randomization) treated, then they will assess their pain sensation. After this assessment, during the same session, their second eye will be treated and they will be asked to complete the same assessment for this second eye. The provided form to assess this outcome is a numeric scale from 0 (no pain) to 10 (worst possible pain) using the Wong-Baker Faces scale.	At time of enrolment

Collaborators and Investigators

• Sponsor: University of Alberta
• Collaborators: Alberta Retina Consultant
• Investigators: Principal Investigator: Matthew Tennant, MD, FRCSC, University of Alberta

Study record dates

Study Major Dates

• Study Start (Estimated): October 15, 2026
• Primary Completion (Estimated): April 1, 2027
• Study Completion (Estimated): May 1, 2027

Study Registration Dates

• First Submitted: October 7, 2024
• First Submitted That Met QC Criteria: October 14, 2024
• First Posted (Actual): October 21, 2024

Study Record Updates

• Last Update Posted (Estimated): October 29, 2025
• Last Update Submitted That Met QC Criteria: October 27, 2025
• Last Verified: October 1, 2025

More Information

Terms related to this study

• Keywords: Panretinal Photocoagulation; Diabetic retinopathy treatment; Vibration Anesthesia Device; Perioperative Pain Alleviation
• Additional Relevant MeSH Terms: Neurologic Manifestations; Pathological Conditions, Signs and Symptoms; Signs and Symptoms; Pain; Physiological Effects of Drugs; Central Nervous System Depressants; Anesthetics
• Other Study ID Numbers: Pro00144813

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: Yes
• product manufactured in and exported from the U.S.: Yes