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

Keratoconus Clinical Trial

Official title:

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

Clinical Trial Details — Status: Completed

Administrative data

• NCT number: NCT02485951
• Other study ID #: ShaheedBMU54
• Status: Completed
• Phase: N/A
• First received: June 13, 2015
• Last updated: April 19, 2016
• Start date: January 2014

Study information

• Verified date: June 2015
• Source: Shahid Beheshti University of Medical Sciences
• Contact: n/a
• Is FDA regulated: No
• Health authority: Iran: Shahid Beheshti University of Medical Sciences
• Study type: Interventional

Clinical Trial 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.

Recruitment information / eligibility

• Status: Completed
• Enrollment: 49
• Est. primary completion date: June 2015
• Accepts healthy volunteers: No
• Gender: Both
• Age group: 18 Years to 50 Years

Eligibility

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 Design

Allocation: Randomized, Endpoint Classification: Safety/Efficacy Study, Intervention Model: Parallel Assignment, Masking: Single Blind (Subject), Primary Purpose: Treatment

Related Conditions & MeSH terms

• Keratoconus

Intervention

Procedure:
• Central air injection
Air was injected inside the trephination site in the central injection group.
• Peripheral air injection
Air was injected at the corneal periphery outside the trephination site.

Locations

Country	Name	City	State
Iran, Islamic Republic of	Ophthalmic Research Center	Tehran

Sponsors (1)

Lead Sponsor	Collaborator
Shahid Beheshti University of Medical Sciences

Country where clinical trial is conducted

Iran, Islamic Republic of, 

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	The rate of successful big-bubble formation		One year	Yes