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

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

Status
Completed
Phases
NA
Study type
Interventional
Source
ClinicalTrials.gov
Registry ID
NCT02485951
Enrollment
49
Registered
2015-06-30
Start date
2014-01-31
Completion date
Unknown
Last updated
2016-04-20

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Keratoconus

Keywords

deep anterior lamellar keratoplasty, big-bubble technique, peripheral air injection, keratoconus

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.

Interventions

PROCEDURECentral air injection

Air was injected inside the trephination site in the central injection group.

PROCEDUREPeripheral air injection

Air was injected at the corneal periphery outside the trephination site.

Sponsors

Shahid Beheshti University of Medical Sciences
Lead SponsorOTHER

Study design

Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
SINGLE (Subject)

Eligibility

Sex/Gender
ALL
Age
18 Years to 50 Years
Healthy volunteers
No

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.

Design outcomes

Primary

MeasureTime frame
The rate of successful big-bubble formationOne year

Countries

Iran

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: Feb 4, 2026