Evaluation of Deep Topical Fornix Nerve Block Versus Topical Anaesthesia Procedure

Evaluation of Deep Topical Fornix Nerve Block Versus Topical Anaesthesia in Patients Undergoing Implantable Contact Lens Procedure

General anaesthesia now a days is not the first choice in phakic intra ocular lens surgery (Phakic IOL) , the short duration of the surgery, general anaesthesia complications, decrease the length of hospital stay and decreasing the costs direct the interest to the regional anaesthesia By the time the traditional retro and peribulbar injections recede to a newer techniques that is safer and cheaper, sub tenon's block using a blunt needle took over due to the more safety profile Even though, still serious problems can occur specially in patients with long axial length.

Deep topical fornix nerve block anaesthesia (DTFNB) and topical anaesthesia gradually took over with promising and successful results, decreasing length of hospital stay and increasing patient satisfaction and fewer margins of complications.

In this study the investigators compared topical anaesthesia alone with DTFNBA in patients undergoing posterior chamber phakic IOL surgery (Visian ICL).

Study Overview

• Status: Unknown
• Conditions: Local Anesthesia; Satisfaction
• Intervention / Treatment: Drug: 0.5% bupivacaine; Drug: 2% tetracaine local anaesthetic drops

Detailed Description

102 patients scheduled for elective ICL/TICL implantation surgery were enrolled in this study after obtaining approval from the institutional ethical committee and written patients consent. the investigators are planning a study of matched sets of patients receiving the case and control treatments with 1 matched control(s) per experimental subject. Prior data indicate that the probability of a treatment failure among controls is 0.05 and the correlation coefficient for exposure between matched experimental and control subjects is 0.1. The true odds ratio for failure in experimental subjects relative to control subjects is 0.1, so the investigators needed to study 51 experimental subjects with 1 matched control(s) per experimental subject to be able to reject the null hypothesis that this odds ratio equals 1 with probability (power) 0.7. The Type I error probability associated with this test of this null hypothesis is 0.3.

All patients were assessed and only those cooperative understanding patients who were deemed suitable for topical and DTFNBA were included in the study. Very anxious patients were omitted from the study.

All the operations were done by one surgeon . Patients were prepared for bilateral implantable contact lens/toric implantable contact lens( ICL/TICL) procedure on the same day.

Group I (1 eye) received topical anaesthetic drops and Group 2 (the second eye) received DTFNBA. Before giving the anaesthetics, a peripheral vein was cannulated and heart rate, oxygen saturation and non-invasive arterial blood pressure were monitored.

Topical anaesthesia was done with 2% tetracaine local anaesthetic drops and DTFNBA was performed using two sponges (2x3mm) soaked with 0.5% bupivacaine, applied deep in the conjunctival fornices after anaesthetising the conjunctiva with tetracaine local anaesthetic drops. The sponges were removed after 15 minutes. The anaesthetic effect was tested by grasping the limbus with Castroviejo 0.12 tissue forceps.

Pain was estimated by the patient using a simple pain score: no pain =0; that does not interfere with the surgical technique, discomfort=1; the surgical technique is performed with difficulty, pain=2; the surgeon is unable to continue the surgical technique . The scoring was done during different stages of surgery: lid retraction while inserting a speculum, tolerance to the microscope light, corneal incision, intraocular lens insertion, tucking of footplates, irrigation aspiration (I/A )of viscoelastic, peripheral iridectomy.

The surgical technique was performed through a clear corneal 3.2 mm tunnel incision, followed by sodium hyalurounate injection, ICL implantation and unfolding, tucking of trailing footplates then side port incision and tucking of leading footplates, myostat injection, then peripheral iridectomy . The total operative time was recorded for every case. If the pain score was 0 or 1, no further management was required but if the pain score was 2 at any stage, 1% preservative free lidocaine was injected intracamerally. Parametric data were analyzed using Students t-test; non parametric data were compared using the Chi-square test. A P value of <0.05 was considered statistically significant.

• Study Type: Interventional
• Enrollment (Anticipated): 102
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Saudi Arabia
  • West
    • Khamis Mushayt, West, Saudi Arabia, 516
      • Magrabi Aseer ,KSA
      • Sub-Investigator: Sherif Eissa, Consultant

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years to 90 years (ADULT, OLDER_ADULT)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

Description

Inclusion Criteria:

• cooperative understanding patients

Exclusion Criteria:

• Very anxious patients
• coagulopathy
• refusal

Study Plan

How is the study designed?

Design Details

• Primary Purpose: HEALTH_SERVICES_RESEARCH
• Allocation: RANDOMIZED
• Interventional Model: PARALLEL
• Masking: TRIPLE

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
EXPERIMENTAL: Group 2; 0.5% bupivacaine Deep topical fornix nerve block anaesthesia (DTFNB)	Drug: 0.5% bupivacaine; was performed using two sponges (2x3mm) soaked with 0.5% bupivacaine, applied deep in the conjunctival fornices after anaesthetising the conjunctiva with tetracaine local anaesthetic drops. The sponges were removed after 15 minutes. The anaesthetic effect was tested by grasping the limbus with Castroviejo 0.12 tissue forceps.; Other Names: Deep topical fornix nerve block anaesthesia
EXPERIMENTAL: Group 1; 2% tetracaine local anaesthetic drops	Drug: 2% tetracaine local anaesthetic drops; topical anaesthetic drops; Other Names: topical anaesthetic drops

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Measure of pain free surgery and Tolerability	the patient will be examined for optimum pain free condition (anesthesia)that allow the surgeon to proceed	during the surgical procedure, 15 minutes

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
patient satisfaction	Patient satisfaction concerning the procedure using a 2-point scale (1=satisfied, I would want the same anaesthesia/analgesia method for the next surgery, 2=unsatisfied, I would want a different anaesthesia/ analgesia method for the next surgery)	one hour post operative

Collaborators and Investigators

• Sponsor: Cairo University

Study record dates

Study Major Dates

• Study Start: August 1, 2014
• Primary Completion (ANTICIPATED): October 1, 2014
• Study Completion (ANTICIPATED): October 1, 2014

Study Registration Dates

• First Submitted: July 16, 2014
• First Submitted That Met QC Criteria: July 18, 2014
• First Posted (ESTIMATE): July 22, 2014

Study Record Updates

• Last Update Posted (ESTIMATE): July 22, 2014
• Last Update Submitted That Met QC Criteria: July 18, 2014
• Last Verified: July 1, 2014

More Information

Terms related to this study

• Keywords: topical anesthesia; deep topical fornix nerve block; implantable contact lens procedure
• Additional Relevant MeSH Terms: Physiological Effects of Drugs; Central Nervous System Depressants; Peripheral Nervous System Agents; Sensory System Agents; Anesthetics; Anesthetics, Local; Bupivacaine; Tetracaine
• Other Study ID Numbers: 1234656