Pain Management During Panretinal Photocoagulation for Diabetic Retinopathy: Safety and Efficacy of Peribulbar Anesthesia

June 8, 2026 updated by: Asociación para Evitar la Ceguera en México

Safety and Efficacy of Peribulbar Anesthesia for Pain Management in Patients With Proliferative Diabetic Retinopathy During Panretinal Photocoagulation

The purpose of this study was to compare two different anesthesia methods for pain control during panretinal photocoagulation (PRP), a type of laser surgery that treats proliferative diabetic retinopathy (PDR).

The study included eyes from patients with diabetes and proliferative diabetic retinopathy who were scheduled to undergo their first PRP session. Participants were split into two groups to receive either peribulbar anesthesia, which is a type of anesthesia injected through the eyelid, or a sham injection with topical anesthesia only.

Pain on a numerical scale and vital signs were recorded before and for 15 minutes during PRP. These results were compared between the two groups to determine which method delivers superior pain control.

Study Overview

Status

Completed

Conditions

Intervention / Treatment

Study Type

Interventional

Enrollment (Actual)

50

Phase

  • Phase 4

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • Mexico
    • Mexico City
      • Mexico City, Mexico City, Mexico, 04030
        • Asociacion Para Evitar la Ceguera en Mexico, I.A.P.

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  • Adults aged 18 years or older with proliferative diabetic retinopathy
  • Scheduled to undergo their first PRP session
  • Able to maintain the required posture at the slit lamp throughout the procedure

Exclusion Criteria:

  • History of phobic anxiety disorder related to needles or injections
  • Known allergies or hypersensitivity to lidocaine, bupivacaine, or tetracaine
  • Use of analgesics within 24 hours prior to treatment
  • Cognitive or motor impairments that could hinder effective communication of pain.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: Single

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: Peribulbar anesthesia intervention group
The intervention administered was topical anesthesia with peribulbar anesthesia consisting of a lidocaine and bupivacaine injection.
Drug: Peribulbar anesthesia with 0.5% bupivacaine and 2% lidocaine
A mixture of 1.5 mL of 0.5% bupivacaine and 1.5 mL of 2% lidocaine was prepared in a 3 mL syringe. The peribulbar injection was administered using a 25G needle inserted horizontally through the inferior palpebral conjunctiva, directed axially over the infraorbital rim, and then angled upward to deliver the anesthetic into the orbit.
Drug: Tetracaine 5% drops
A single drop of topical 5% tetracaine
Sham Comparator: Control group
The control group received only topical anesthesia and a sham peribulbar injection.
Drug: Tetracaine 5% drops
A single drop of topical 5% tetracaine

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Pain perception during PRP administration
Time Frame: Pain on the NRS scale was measured at the 1-, 5-, 10-, and 15-minute marks while undergoing PRP application in each eye.
patient perception of pain during PRP administration in each eye, measured using the Numerical Rating Scale (NRS). The NRS measures pain intensity on a scale of 0 to 10, where 0 corresponds to the absence of pain and 10 represents the worst pain imaginable.
Pain on the NRS scale was measured at the 1-, 5-, 10-, and 15-minute marks while undergoing PRP application in each eye.

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Heart rate
Time Frame: at baseline before the start of PRP, and at the 1-, 5-, 10-, and 15-minute marks while undergoing PRP application in each eye.
Heart rate measured as beats per minute using the Aquarius Vital Sign Monitor (Shenzhen Northern Meditec Limited, Shenzhen, China)
at baseline before the start of PRP, and at the 1-, 5-, 10-, and 15-minute marks while undergoing PRP application in each eye.
Respiratory rate
Time Frame: at baseline before the start of PRP, and at the 1-, 5-, 10-, and 15-minute marks while undergoing PRP application in each eye.
Respiratory rate measured as breaths per minute using the Aquarius Vital Sign Monitor (Shenzhen Northern Meditec Limited, Shenzhen, China)
at baseline before the start of PRP, and at the 1-, 5-, 10-, and 15-minute marks while undergoing PRP application in each eye.
Oxygen saturation
Time Frame: at baseline before the start of PRP, and at the 1-, 5-, 10-, and 15-minute marks while undergoing PRP application in each eye.
Oxygen saturation was measured as SpO2 using the Aquarius Vital Sign Monitor (Shenzhen Northern Meditec Limited, Shenzhen, China)
at baseline before the start of PRP, and at the 1-, 5-, 10-, and 15-minute marks while undergoing PRP application in each eye.

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Asociación para Evitar la Ceguera en México

Investigators

  • Principal Investigator: José Gerardo García Aguirre, MD, Asociacion Para Evitar la Ceguera en Mexico, I.A.P.

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

July 6, 2023

Primary Completion (Actual)

March 21, 2024

Study Completion (Actual)

June 21, 2024

Study Registration Dates

First Submitted

June 1, 2026

First Submitted That Met QC Criteria

June 8, 2026

First Posted (Actual)

June 10, 2026

Study Record Updates

Last Update Posted (Actual)

June 10, 2026

Last Update Submitted That Met QC Criteria

June 8, 2026

Last Verified

June 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • RET-PFC01

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

IPD Plan Description

De-identified participant data will be made available to qualified researchers upon request to the corresponding author.

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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