Anaesthesia for Ophthalmic Surgery: How "Retro" is the Peribulbar Block?

June 8, 2011 updated by: Sunnybrook Health Sciences Centre
Ophthalmic surgery on the posterior section of the eye can either be performed under general anaesthesia or under local aneasthesia. The local anaesthesia is performed by injecting local anaesthetics behind the eye. There are two techniques: Either the needle is placed into the muscle cone formed by the four recti muscles - this is called intraconal or retrobulbar block, or the needle is placed outside of the muscle cone - this would be called extraconal or peribulbar. In our hospital the investigators usually perform the peribulbar block since it is easier to perform and has a smaller risk to injure the eye. The investigators however realize that the parabulbar block is sometimes very efficient and sometimes not, thus requiring a second or third injection. Now investigators are able to visualize where the local anaesthetics spreads with the help of ultrasound imaging. The aim of the study is to observe and to describe the incidence of intraconal spread of local anaesthetics when a peribulbar block is performed.

Study Overview

Status

Completed

Conditions

Intervention / Treatment

Study Type

Observational

Enrollment (Anticipated)

100

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

  • Canada
    • Ontario
      • Toronto, Ontario, Canada, M4N 3M5
        • Sunnybrook Health Science Centres

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

18 years and older (Adult, Older Adult)

Accepts Healthy Volunteers

No

Genders Eligible for Study

All

Sampling Method

Probability Sample

Study Population

100 consecutive patients (men and women) of at least 18 years of age undergoing an ophthalmic procedure on the posterior section of the eye under local anaesthesia, i.e. with a peribulbar block.

Description

Inclusion Criteria:

-informed consent

Exclusion Criteria:

  • coagulation disorder
  • INR over 1.5 and/or a platelet count less than 75 X 109/L,
  • pathological myopia,
  • inability of the patient to lie down for the operation for more than 2 hours
  • lack of informed consent.

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

  • Observational Models: Cohort
  • Time Perspectives: Prospective

Cohorts and Interventions

Group / Cohort
Intervention / Treatment
Ophthalmic surgery patients
Patients (men and women) of at least 18 years of age undergoing an ophthalmic procedure on the posterior section of the eye under local anaesthesia, i.e. with a peribulbar block. Inclusion and exclusion criteria for the study are the same as for the peribulbar anaesthesia.
Procedure: Ultrasound detection of local anesthetics spread
During the parabulbar injection the ultrasound operator experienced in ultrasound guided retrobulbar block will assess whether there is spread of local anaesthetic in the central cone just behind the sclera (yes or no). The anaesthesist performing the block will be blinded to the ultrasound visualized spread of local anaesthetic.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Incidence of detectable retrobulbar spread of local anaesthetics during peribulbar injection.
Time Frame: At start (During peribulbar injection)
The outcome measure is the description of the spread of local anesthetics during the injection of the drug via the parabulbar needle.
At start (During peribulbar injection)

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Assessment of block quality
Time Frame: 20 Minutes after block
Assessment of the block quality by ophthalmic surgeon just before surgery starts and at least 20 minutes after the block: complete akinesia and anaesthesia or partial akinesia/anaesthesia.
20 Minutes after block

Collaborators and Investigators

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

Sponsor

Sunnybrook Health Sciences Centre

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

January 1, 2011

Primary Completion (Actual)

June 1, 2011

Study Completion (Actual)

June 1, 2011

Study Registration Dates

First Submitted

December 8, 2010

First Submitted That Met QC Criteria

December 10, 2010

First Posted (Estimate)

December 13, 2010

Study Record Updates

Last Update Posted (Estimate)

June 9, 2011

Last Update Submitted That Met QC Criteria

June 8, 2011

Last Verified

December 1, 2010

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • Retro-Parabulbar

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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