Lacrimal Dilator-Facilitated vs Standard Sub-Tenon's Block

to Compare Lacrimal Dilator-facilitated Incisionless and Standard STB With Wescott Scissors Clinical Trial

Official title:

Lacrimal Dilator-Facilitated Incisionless Vs. Standard Sub-Tenon's Block: A Randomized, Prospective and Non-inferiority Comparative Study

Clinical Trial Details — Status: Completed

Administrative data

• NCT number: NCT04345172
• Other study ID #: KA19/165
• Status: Completed
• Phase: N/A
• Start date: January 1, 2019
• Est. completion date: October 15, 2019

Study information

• Verified date: April 2020
• Source: Baskent University
• Contact: n/a
• Is FDA regulated: No
• Study type: Interventional

Clinical Trial Summary

Standard sub-Tenon's block involves incision (dissection) of conjunctiva and Tenon's capsule with the help of blunt scissors and forceps, insertion of a blunt sub-Tenon's cannula under the Tenon's capsule and injection of local anaesthetic agent. This block is frequently associated with minor complications such as chemosis and subconjunctival haemorrhage. Different variations of incisionless sub-Tenon's block including the use of lacrimal dilator have been described to reduce minor complications and facilitate insertion of blunt cannula. Lacrimal dilator creates a small aperture in the conjunctiva and Tenon's capsule thus avoids incision. After ethics approval, patients undergoing elective cataract surgery were enrolled to receive sub-Tenon's block performed without incision with a lacrimal dilator (Group LD) or with incision using Wescott scissors and blunt forceps (Group WS). All patients received 3 mL 2% lidocaine without any adjuvant. No sedation was administered. Demographic of the patients, duration of the procedure, analgesia (pain), akinesia, duration of the procedure intraoperative chemosis, subconjunctival haemorrhage on the first postoperative day. We aimed to compare lacrimal dilator-facilitated and standard sub-Tenon's block effectiveness and incidence of chemosis and subconjunctival haemorrhage.

Description:

The patients were randomly allocated to receive STB performed with a lacrimal dilator (Group LD) and with a Wescott scissors (Group WS). Randomization was ensured by sealed envelopes prepared according to a computer-generated table and the envelopes were opened by the operator just before the sub-Tenon's block.

Study protocol Local anaesthetic eye drops were installed into the conjunctiva, followed by iodine 5% aqueous drops to the conjunctival sac for 3 minutes.19 An eye lid speculum was inserted.

In group LD, the conjunctiva and Tenon's capsule were lifted together tightly with a blunt forceps like a tent in the inferonasal quadrant and a punctal dilatator was placed tangential to the globe creating a round and small hole at 5 mm posterior to limbus. The block was performed using smooth rounded tip, 19 G, 1 inch sub-Tenon's cannula .

In Group WS, after lifting the conjunctiva and Tenon's capsule together with a blunt forceps, incision was performed with a blunt tip Westcott scissors in the inferonasal conjunctival at 5 mm posterior to limbus to expose sub-Tenon's space. The block was performed with the above sub-Tenon's cannula.

All patients received lidocaine 2%, 3 mL without any adjuvant. No sedative was administered. All the blocks and surgeries were performed by the same investigator, but block evaluations were made by another investigator who was blinded to the technique used. All patients were discharged on the day of surgery.

The parameters recorded included demographic of the patients, duration of the procedure, analgesia (pain), akinesia, duration of the procedure intraoperative chemosis, subconjunctival haemorrhage on the first postoperative day. Analgesia was evaluated using a numeric rating scale for pain (0-10; 0 - no pain, 10 - the worst imaginable pain) immediately after the operation. Akinesia (ocular movements) were checked according to 4-primary gazes 10 minutes after STB. Chemosis and conjunctival haemorrhage (1st postoperative day) were assessed according to the number of quadrant or quadrants affected (superior nasal, superior temporal, inferior nasal, inferior temporal) using a 5-point scale (0-4; 0 - no for chemosis and haemorrhage, 4 for chemosis or haemorrhage in all 4 quadrants).

Recruitment information / eligibility

• Status: Completed
• Enrollment: 64
• Est. completion date: October 15, 2019
• Est. primary completion date: September 30, 2019
• Accepts healthy volunteers: Accepts Healthy Volunteers
• Gender: All
• Age group: 20 Years to 90 Years

Eligibility

Inclusion Criteria:

patients undergoing cataract surgery by phacoemulsification and intraocular lens implantation

Exclusion Criteria:

allergy to lidocaine, history of previous retinal and strabismus surgery, bleeding disorders and oral anticoagulant use, presence of glaucoma or high IOP, thick pterygia, any pathological condition that conjunctiva and Tenon's capsule cannot be lifted away from the sclera

Related Conditions & MeSH terms

• to Compare Lacrimal Dilator-facilitated Incisionless and Standard STB With Wescott Scissors

Intervention

Device:
• sub-Tenon's block with a lacrimal dilator group or a Wescott scissors
Local anaesthetic eye drops were installed into the conjunctiva, followed by iodine 5% aqueous drops to the conjunctival sac for 3 minutes.19 An eye lid speculum was inserted. In group LD, the conjunctiva and Tenon's capsule were lifted together tightly with a blunt forceps like a tent in the inferonasal quadrant and a punctal dilatator (Castroviejo Lacrimal Dilatator, Katena Products, Inc, Denville, NJ, USA) was placed tangential to the globe creating a round and small hole at 5 mm posterior to limbus (Fig.1). The block was performed using smooth rounded tip, 19 G, 1 inch sub-Tenon's cannula (Visitec, Beaver-Visitec International Ltd, Warwickshire, UK). In Group WS, after lifting the conjunctiva and Tenon's capsule together with a blunt forceps, incision was performed with a blunt tip Westcott scissors in the inferonasal conjunctival at 5 mm posterior to limbus to expose sub-Tenon's space.

Locations

Country	Name	City	State
Turkey	Baskent University, Adana Research and Training Center	Adana

Sponsors (1)

Lead Sponsor	Collaborator
Baskent University

Country where clinical trial is conducted

Turkey, 

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	chemosis	swelling of the conjunctiva	10 minutes after intervention
Secondary	subconjunctival haemorrhage	haemorrhage due to tearing or severing of blood vessels during dissection and injection	on the postoperative first day