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

Sponsor

Shahid Beheshti University of Medical Sciences (Other)

Overall Status

Completed

CT.gov ID

NCT02485951

Collaborator

(none)

Enrollment

Location

Arms

Study Details

Study Description

Brief Summary

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.

Condition or Disease	Intervention/Treatment	Phase
Keratoconus	Procedure: Central air injection Procedure: Peripheral air injection	N/A

Study Design

Study Type:

Interventional

Actual Enrollment :

49 participants

Allocation:

Randomized

Intervention Model:

Parallel Assignment

Masking:

Single (Participant)

Primary Purpose:

Treatment

Official Title:

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

Study Start Date :

Jan 1, 2014

Actual Primary Completion Date :

Jun 1, 2015

Arms and Interventions

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.

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.

Outcome Measures

Primary Outcome Measures

The rate of successful big-bubble formation [One year]

Eligibility Criteria

Criteria

Ages Eligible for Study:

18 Years to 50 Years

Sexes Eligible for Study:

All

Accepts Healthy Volunteers:

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.

Contacts and Locations

Locations

	Site	City	State	Country	Postal Code
1	Ophthalmic Research Center	Tehran		Iran, Islamic Republic of

Sponsors and Collaborators

Shahid Beheshti University of Medical Sciences

Investigators

None specified.

Study Documents (Full-Text)

None provided.

More Information

Publications

None provided.

Responsible Party:

Sepehr Feizi, MD, Shahid Beheshti University of Medical Sciences

ClinicalTrials.gov Identifier:

NCT02485951

Other Study ID Numbers:

ShaheedBMU54

First Posted:

Jun 30, 2015

Last Update Posted:

Apr 20, 2016

Last Verified:

Jun 1, 2015

Keywords provided by Sepehr Feizi, MD, Shahid Beheshti University of Medical Sciences

deep anterior lamellar keratoplasty

big-bubble technique

peripheral air injection

keratoconus

Additional relevant MeSH terms:

Keratoconus

Study Results

No Results Posted as of Apr 20, 2016