Comparative Study Between Different Additives to Lidocaine 2٪ for Peribulbar Block in Vitreoretinal Surgery

Comparative Study Between Different Additives to Lidocaine 2٪ for Peribulbar Block in Vitreoretinal Surgery (Prospective Comparative Randomized Controlled Trial

Peribulbar block, is the favored anesthetic technique for numerous ophthalmic procedures due to its lower rate of associated complications .

Retinal surgeries have many problems to the anesthesiologists as these operations are often lengthy , involve a significant risk of postoperative pain ,and typically involve an elderly patient population with multiple comorbidities .

Many anesthesiologists consider the peribulbar block as a safe technique; however, it has the disadvantage of a slow onset of orbital akinesia and to produce it a more substantial volume or repeated injections of local anesthetic solution is required due to limited diffusion of local anesthetics . This also increases the frequency of complications, such as globe perforation and peribulbar hemorrhage .

To prevent this and to increase tissue perfusion, hyaluronidase and other adjuvants such as clonidine, epinephrine and alkalinization of local anesthetics were used to improve peribulbar block.

Hyaluronidase may reduce tissue viscosity , which facilitate the complete diffusion of anesthetic solution along tissue planes .

in regional anesthesia is the addition of hyaluronidase is associated with benefits such as faster onest of action and impoved block quality ,however ,evidence regarding its efficacy in peribulbar techniques remains inconsistent.

To improve the quality and duration of the block, various adjuvants have been investigated. Two promising agents are Midazolam, a benzodiazepine with hypothesized peripheral GABA-ergic action, and Cisatracurium, a non-depolarizing neuromuscular blocking agent. Midazolam may enhance sensory block and provide amnesia, while cisatracurium directly induces chemical paralysis of the extraocular muscles. However, a direct comparative study of their efficacy and safety profiles in this context is lacking. This study aims to fill that gap .

90 eligible patients were randomly allocated into three groups using computer-generated random numbers placed in sealed, opaque envelopes.

• Group L (Control): lidocaine 2٪ (4 ml) + Normal Saline (1 ml).
• Group M (Midazolam): lidocaine 2٪ % (4 ml) + Midazolam (1 mg in 1 ml).
• Group C (Cisatracurium): lidocaine 2٪ (4 ml) + Cisatracurium (0.5 mg in 0.5 ml) + Normal Saline (0.5 ml).

The total volume of the injectate was standardized to 5 ml for all groups.

Study Overview

• Status: Not yet recruiting
• Conditions: Vitreoretinal Surgery
• Intervention / Treatment: Drug: Group L (Control); Drug: · Group M (Midazolam):; Drug: · Group C (Cisatracurium):

• Study Type: Interventional
• Enrollment (Estimated): 90
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: waleed adel Ahmed, lecturer; Phone Number: +201006392210; Email: waleed.salama@med.sohag.edu.eg
• Study Contact Backup: Name: ahmed hamody hasan, assistant professor; Phone Number: 01001752726; Email: Hamodyanesthesia@gmail.com

Study Locations

• Egypt
  • Sohag Governorate
    • Sohag, Sohag Governorate, Egypt, 0123
      • Suhag faculty of medicine
      • Contact: waleed Ahmed; Phone Number: 01006392210; Email: waleed.salama@med.sohag.edu.eg

Participation Criteria

Eligibility Criteria

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

Description

Inclusion Criteria:

• American Society of Anesthesiologists (ASA) physical status I-III patients -enrolled for elective vitreoretinal procedures under peribulbar block.

Exclusion Criteria:

• Patient refusal
• allergy to study drugs
• coagulopathy
• infection at the injection site
• significant axial myopia (axial length >26mm)
• neurological or neuromuscular disorders
• pregnancy
• inability to communicate.

Study Plan

How is the study designed?

Design Details

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

Number of Arms

3

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Placebo Comparator: · Group L (Control): lidocaine 2٪ (4 ml) + Normal Saline (1 ml).; · Group L (Control): peribulper lidocaine 2٪ (4 ml) + Normal Saline (1 ml).	Drug: Group L (Control); peribulber injection of lidocaine 2٪ (4 ml) + Normal Saline (1 ml).
Active Comparator: Group M (Midazolam): lidocaine 2٪ % (4 ml) + Midazolam (1 mg in 1 ml).; Group M (Midazolam):peribulber injection of lidocaine 2٪ % (4 ml) + Midazolam (1 mg in 1 ml).	Drug: · Group M (Midazolam): peribulber injection of idocaine 2٪ % (4 ml) + Midazolam (1 mg in 1 ml).
Active Comparator: · Group C (Cisatracurium): lidocaine 2٪ (4 ml) + Cisatracurium (0.5 mg in 0.5 ml) + Normal Saline (; · Group C (Cisatracurium): peribulber injection oflidocaine 2٪ (4 ml) + Cisatracurium (0.5 mg in 0.5 ml) + Normal Saline (0.5 ml).	Drug: · Group C (Cisatracurium): peribulber injection of lidocaine 2٪ (4 ml) + Cisatracurium (0.5 mg in 0.5 ml) + Normal Saline (0.5 ml).

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Onset of Akinesia	onset of muscle paralysis (loss of muscle tone)	investigator assess muscle tone immediately after start of anesthesia and every 15 minute up to end of surgery

Collaborators and Investigators

• Sponsor: Sohag University

Study record dates

Study Major Dates

• Study Start (Estimated): May 1, 2026
• Primary Completion (Estimated): June 15, 2026
• Study Completion (Estimated): June 15, 2026

Study Registration Dates

• First Submitted: February 10, 2026
• First Submitted That Met QC Criteria: April 6, 2026
• First Posted (Actual): April 9, 2026

Study Record Updates

• Last Update Posted (Actual): April 9, 2026
• Last Update Submitted That Met QC Criteria: April 6, 2026
• Last Verified: April 1, 2026

More Information

Terms related to this study

• Keywords: Ophthalmic anesthesia.; Vitreoretinal surgery,
• Additional Relevant MeSH Terms: Heterocyclic Compounds; Heterocyclic Compounds, 2-Ring; Heterocyclic Compounds, Fused-Ring; Benzazepines; Benzodiazepines; Midazolam; cisatracurium
• Other Study ID Numbers: soh-med-25-10----18PD

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: UNDECIDED

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No