AzTrials
AzTrials

Proliferative Diabetic RetinopathyPhase 4NCT07640256

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

A Phase 4 study testing Peribulbar anesthesia with 0.5% bupivacaine and 2% lidocaine and Tetracaine 5% drops in people with Proliferative Diabetic Retinopathy, run by Asociación para Evitar la Ceguera en México at 1 site in Mexico.

Completed

Finished. The study has ended and is not enrolling. Results may be posted on the official record.

Official record
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Trial summary

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). Read more about this study

Who is it for?
Ages 18 years and older
Conditions the study is for
Proliferative Diabetic Retinopathy
What is being tested?
Peribulbar anesthesia with 0.5% bupivacaine and 2% lidocaine and Tetracaine 5% drops
Type of treatment
Injection or infusion
Could I receive a placebo?
Yes, some participants may receive a placebo
How many people
50 participants
Where
1 siteMexico
Study dates
6 Jul 2023to 21 Jun 2024
Phase
Phase 4
Are there results?
None posted in the registry

Key requirements

Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.

  • Ages 18 years and older
  • All sexes
  • No healthy volunteers
  • Adult, Older adult

Who may be able to join

  • 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

Who cannot join

  • 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.

Trial locations and contacts

1 site in 1 country.

Mexico1 site

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

    Mexico City, Mexico City, 04030

Other trials in Mexico

About this study

Official title: 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.

Being tested
Peribulbar anesthesia with 0.5% bupivacaine and 2% lidocaine, Tetracaine 5% drops
Keywords
pain management, panretinal photocoagulation, proliferative diabetic retinopathy, peribulbar anesthesia
Medical subject headings
Agnosia

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

  • Peribulbar anesthesia with 0.5% bupivacaine and 2% lidocaineDrug

    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.

  • Tetracaine 5% dropsDrug

    A single drop of topical 5% tetracaine

Study groups in NCT07640256
Study groupRoleWhat they receive
Peribulbar anesthesia intervention groupExperimentalThe intervention administered was topical anesthesia with peribulbar anesthesia consisting of a lidocaine and bupivacaine injection.
Receives: Drug: Peribulbar anesthesia with 0.5% bupivacaine and 2% lidocaine; Drug: Tetracaine 5% drops
Control groupSham comparatorThe control group received only topical anesthesia and a sham peribulbar injection.
Receives: Drug: Tetracaine 5% drops

What is being measured

The primary outcome is the main question the study is designed to answer.

  1. Pain perception during PRP administration

    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.

    Measured: Pain on the NRS scale was measured at the 1-, 5-, 10-, and 15-minute marks while undergoing PRP application in each eye.

Secondary outcomes (3)

  1. Heart rate

    Heart rate measured as beats per minute using the Aquarius Vital Sign Monitor (Shenzhen Northern Meditec Limited, Shenzhen, China)

    Measured: at baseline before the start of PRP, and at the 1-, 5-, 10-, and 15-minute marks while undergoing PRP application in each eye.

  2. Respiratory rate

    Respiratory rate measured as breaths per minute using the Aquarius Vital Sign Monitor (Shenzhen Northern Meditec Limited, Shenzhen, China)

    Measured: at baseline before the start of PRP, and at the 1-, 5-, 10-, and 15-minute marks while undergoing PRP application in each eye.

  3. Oxygen saturation

    Oxygen saturation was measured as SpO2 using the Aquarius Vital Sign Monitor (Shenzhen Northern Meditec Limited, Shenzhen, China)

    Measured: at baseline before the start of PRP, and at the 1-, 5-, 10-, and 15-minute marks while undergoing PRP application in each eye.

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

  1. First posted10 Jun 2026
  2. Study start6 Jul 2023
  3. Primary completion21 Mar 2024
  4. Study completion21 Jun 2024

Resources

More details

For doctors and researchers: how the study is designed, who runs it, and its registry IDs.

Study design
Study type
Interventional
Phase
Phase 4
Primary purpose
Treatment
Allocation
Randomised
Intervention model
Parallel groups
Masking
Single blind
Who is masked
Participant
Enrolment
50 participants (actual)
IDs, dates and publications
ClinicalTrials.gov ID
NCT07640256
Sponsor's protocol ID
RET-PFC01
Status last verified
Jul 2026
First submitted
1 Jun 2026
Last updated
14 Jul 2026
Results posted
No
Data monitoring committee
No
FDA-regulated drug
No
FDA-regulated device
No
Individual data sharing
No: De-identified participant data will be made available to qualified researchers upon request to the corresponding author.

Publications

  • Kumar CM. Orbital regional anesthesia: complications and their prevention. Indian J Ophthalmol. 2006 Jun;54(2):77-84. doi: 10.4103/0301-4738.25826.

    PubMed 16770022

  • Schobel HP, Ringkamp M, Behrmann A, Forster C, Schmieder RE, Handwerker HO. Hemodynamic and sympathetic nerve responses to painful stimuli in normotensive and borderline hypertensive subjects. Pain. 1996 Aug;66(2-3):117-24. doi: 10.1016/0304-3959(96)03079-5.

    PubMed 8880832

  • McGrath PA. Psychological aspects of pain perception. Arch Oral Biol. 1994;39 Suppl:55S-62S. doi: 10.1016/0003-9969(94)90189-9.

    PubMed 7702468

  • Ripart J, Lefrant JY, de La Coussaye JE, Prat-Pradal D, Vivien B, Eledjam JJ. Peribulbar versus retrobulbar anesthesia for ophthalmic surgery: an anatomical comparison of extraconal and intraconal injections. Anesthesiology. 2001 Jan;94(1):56-62. doi: 10.1097/00000542-200101000-00013.

    PubMed 11135722

  • Duker JS, Belmont JB, Benson WE, Brooks HL Jr, Brown GC, Federman JL, Fischer DH, Tasman WS. Inadvertent globe perforation during retrobulbar and peribulbar anesthesia. Patient characteristics, surgical management, and visual outcome. Ophthalmology. 1991 Apr;98(4):519-26. doi: 10.1016/s0161-6420(91)32262-0.

    PubMed 2052307

  • Malik A, Fletcher EC, Chong V, Dasan J. Local anesthesia for cataract surgery. J Cataract Refract Surg. 2010 Jan;36(1):133-52. doi: 10.1016/j.jcrs.2009.10.025.

    PubMed 20117717

  • Johari M, Moallem M, Amini A, Sanie-Jahromi F. Pain Management Strategies before Pan-Retinal Photocoagulation for Diabetic Retinopathy: A Systematic Review. J Ophthalmol. 2024 Aug 20;2024:6662736. doi: 10.1155/2024/6662736. eCollection 2024.

    PubMed 39502493

  • Gonzalez VH, Wang PW, Ruiz CQ. Panretinal Photocoagulation for Diabetic Retinopathy in the RIDE and RISE Trials: Not "1 and Done". Ophthalmology. 2021 Oct;128(10):1448-1457. doi: 10.1016/j.ophtha.2019.08.010. Epub 2019 Aug 21.

    PubMed 31668888

  • Zakrzewski PA, O'Donnell HL, Lam WC. Oral versus topical diclofenac for pain prevention during panretinal photocoagulation. Ophthalmology. 2009 Jun;116(6):1168-74. doi: 10.1016/j.ophtha.2009.01.022. Epub 2009 Apr 19.

    PubMed 19376588

  • Mafrici M, Fragiotta S, Tarsitano MG, Lorenzi U, Toscani L. Topical anesthesia versus topical and subconjunctival anesthesia combined in diabetic retinopathy photocoagulation. Eur J Ophthalmol. 2024 Mar;34(2):529-533. doi: 10.1177/11206721231199206. Epub 2023 Aug 31.

    PubMed 37654069

  • Tesha PE, Giavedoni LR, Berger AR, Altomare F, Chow DR, Navajas EV, Yoganathan P, Wong DT, Principe A. Subconjunctival lidocaine before laser treatment: a randomized trial. Ophthalmology. 2010 Sep;117(9):1810-4. doi: 10.1016/j.ophtha.2010.01.036. Epub 2010 Jun 8.

    PubMed 20570360

  • Arruda MP, Hira S, Lima RV, Barbosa LIT, Zinher MT, Al-Sharif L, Leal Moreira JLM, Del Valle GS. Pharmacological therapy for relieving pain in panretinal photocoagulation: A network meta-analysis of randomized controlled trials. Surv Ophthalmol. 2025 Jul-Aug;70(4):645-652. doi: 10.1016/j.survophthal.2025.01.018. Epub 2025 Feb 5.

    PubMed 39921002

  • Tsoumani AT, Asproudis IC, Damigos D. Tetracaine 0.5% eyedrops with or without lidocaine 2% gel in topical anesthesia for cataract surgery. Clin Ophthalmol. 2010 Sep 7;4:967-70. doi: 10.2147/opth.s11755.

    PubMed 20856590

  • Richardson C, Waterman H. Pain relief during panretinal photocoagulation for diabetic retinopathy: a national survey. Eye (Lond). 2009 Dec;23(12):2233-7. doi: 10.1038/eye.2008.421.

    PubMed 19169228

  • Wu WC, Hsu KH, Chen TL, Hwang YS, Lin KK, Li LM, Shih CP, Lai CC. Interventions for relieving pain associated with panretinal photocoagulation: a prospective randomized trial. Eye (Lond). 2006 Jun;20(6):712-9. doi: 10.1038/sj.eye.6701989. Epub 2005 Jul 8.

    PubMed 16021194

Questions about this trial

What is this clinical trial studying?

A Phase 4 study testing Peribulbar anesthesia with 0.5% bupivacaine and 2% lidocaine and Tetracaine 5% drops in people with Proliferative Diabetic Retinopathy, run by Asociación para Evitar la Ceguera en México at 1 site in Mexico.

The full registered description is in the About this study section and the official record.

Who may be eligible to take part?

The sponsor lists 3 inclusion and 4 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.

Is this clinical trial currently recruiting?

The record says: finished, as of the sponsor's last update on 14 Jul 2026. Status can change between updates, so confirm with the study contact before making plans.

Where is the study taking place?

The record lists 1 site in Mexico. Whether a site is taking part right now should be confirmed with that site. See every site.

What are the possible benefits and risks?

They depend on the study and the treatment, and no study can promise a benefit. Some participants in this study may receive a placebo. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.

What does this phase mean?

Phase 4 studies take place after a treatment is approved, to learn more about its long-term benefits and risks in everyday use.

Not every study follows the same path, and some studies (observational studies, device studies) have no phase.

Are results available for this study?

The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.

How can a doctor refer a patient or contact the research team?

The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.

What does the primary outcome measure?

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.). It is what the study was designed to measure, not a finding.

Where can I read the original study information?

On the ClinicalTrials.gov record for NCT07640256, which also lists 29 linked publications.

Does a listing mean the treatment is approved or proven to work?

No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.

How often is this information updated?

AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 14 Jul 2026; AzTrials last refreshed its copy on 8 Nov 2026.

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