Central Versus Peripheral Air Injection for DALK (Deep Anterior Lamellar Keratoplasty)

April 19, 2016 updated by: Sepehr Feizi, Shahid Beheshti University of Medical Sciences

Big-bubble Deep Anterior Lamellar Keratoplasty: Central Versus Peripheral Air Injection

Different techniques of deep anterior lamellar keratoplasty (DALK) have been introduced to create a uniform recipient bed, thereby reducing complications, such as interface irregularity and opacification encountered with conventional lamellar keratoplasty. The big-bubble technique provides a planned, safe, quick and consistent baring of Descemet membrane (DM) by injection of air deep into the stroma. Nevertheless, this technique has a long learning curve with a low success rate of big-bubble formation and a high rate of DM perforation when performed by surgeons in training. Different modifications to the original technique using intraoperative instruments such as corneal pachymetry, anterior segment optical coherence tomography (OCT), and femtosecond laser, have been used to increase the chances of achieving a successful DM detachment from the deep stroma by air injection. Even with these innovations, the rate of successful big-bubble formation did not reach 100%. Recently, the investigators described a modification to the original big-bubble DALK in which a 27-gauge needle was inserted into the stroma peripherally from the trephination site towards the limbus. The investigators found that air injection peripheral to the trephination can effectively and reproducibly separate the corneal stroma from the Descemet membrane (DM). This study was aimed to compare the success rate and complications of big-bubble DALK using central versus peripheral air injection performed by senior cornea fellows under the supervision of an experienced faculty member in an academic hospital.

Study Overview

Status

Completed

Conditions

Intervention / Treatment

Study Type

Interventional

Enrollment (Actual)

49

Phase

  • Not Applicable

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

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 to 50 years (Adult)

Accepts Healthy Volunteers

No

Genders Eligible for Study

All

Description

Inclusion Criteria:

  • Patients with moderate (48 D < mean keratometry < 55 D) to advanced (mean keratometry ≥ 55 D or immeasurable keratometry) keratoconus were enrolled.

Exclusion Criteria:

  • History of ocular surgery, concomitant ocular pathologies, such as vernal keratoconjunctivitis, cataract, glaucoma, and retinal abnormalities.

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

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

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Active Comparator: Central air injection
The needle was moved radially inside the trephination site and advanced to the central or paracentral cornea.
Procedure: Central air injection
Air was injected inside the trephination site in the central injection group.
Active Comparator: Peripheral air injection
The needle was inserted into the deep stroma from the trephination site and advanced into the peripheral cornea to approximately 1.5 mm anterior to the limbus.
Procedure: Peripheral air injection
Air was injected at the corneal periphery outside the trephination site.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Time Frame
The rate of successful big-bubble formation
Time Frame: One year
One year

Collaborators and Investigators

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

Sponsor

Shahid Beheshti University of Medical Sciences

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, 2014

Primary Completion (Actual)

June 1, 2015

Study Registration Dates

First Submitted

June 13, 2015

First Submitted That Met QC Criteria

June 27, 2015

First Posted (Estimate)

June 30, 2015

Study Record Updates

Last Update Posted (Estimate)

April 20, 2016

Last Update Submitted That Met QC Criteria

April 19, 2016

Last Verified

June 1, 2015

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • ShaheedBMU54

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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