Pocket Versus Tunnel ICRS for Treatment of Keratoconus

NCT ID: NCT05748847

Last Updated: 2024-10-31

Basic Information

• Recruitment Status: COMPLETED
• Clinical Phase: NA
• Total Enrollment: 74 participants
• Study Classification: INTERVENTIONAL
• Study Start Date: 2019-06-01
• Study Completion Date: 2023-04-15

Brief Summary

Keratoconus is a corneal degenerative disease associated with loss of best-corrected visual acuity. The use of intrastromal corneal ring segment implants is indicated to regularize the cornea and to reduce aberrations.

Detailed Description

Keratoconus is a corneal degenerative disease characterized by corneal thinning and subsequent development of irregular astigmatism, diminution of vision and loss of best-corrected visual acuity.

Management of keratoconus includes halting disease progression through a corneal strengthening procedure called corneal collagen cross-linking (CXL) which usually results in stabilizing the condition but with no improvement in visual acuity or quality. Intrastromal corneal ring segment (ICRS) implantation is a well-established procedure for the management of moderate keratoconus with a corneal flattening effect that is associated with improvement of visual acuity and reduction of optical aberrations.

The aim of the study is to evaluate and compare the visual, refractive and topographic outcomes of two different femtosecond laser assisted surgical techniques to create a corneal stromal pocket or a tunnel for implantation of ICRS for the management of central keratoconus

Conditions

Keratoconus

Study Design

• Allocation Method: RANDOMIZED
• Intervention Model: PARALLEL
• Primary Study Purpose: TREATMENT
• Blinding Strategy: SINGLE

Study Groups

Pocket ICRS

Patients in this group underwent 360-degree MyoRing implantation through a femtosecond laser-assisted corneal pocket creation for the management of their central keratoconus.

Group Type: ACTIVE_COMPARATOR

Intrastromal corneal ring segment implantation (Pocket)

Intervention Type: PROCEDURE

Patients in this group are planned to undergo ICRS implantation through a femtosecond laser-assisted pocket creation.

The device creates an intrastromal corneal pocket of 8-mm diameter and a depth of nearly 80% of the corneal thickness at the thinnest location with a superior tunnel incision at 90° of 5-mm width.

Tunnel ICRS

Patients in this group are underwent 340-degree KeraRing implantation through a femtosecond laser-assisted corneal tunnel creation for the management of their central keratoconus.

Group Type: ACTIVE_COMPARATOR

Intrastromal corneal ring segment implantation (Tunnel)

Intervention Type: PROCEDURE

Patients in this group are planned to undergo ICRS implantation through a femtosecond laser-assisted tunnel creation.

The device creates an intrastromal tunnel with a depth of nearly 80% of the corneal thickness at the site of implantation. The tunnel inner and outer diameters are at 5 and 6 mm from the corneal center, respectively with the incision located at the steepest keratometry axis.

Interventions

Intrastromal corneal ring segment implantation (Pocket)

Patients in this group are planned to undergo ICRS implantation through a femtosecond laser-assisted pocket creation.

The device creates an intrastromal corneal pocket of 8-mm diameter and a depth of nearly 80% of the corneal thickness at the thinnest location with a superior tunnel incision at 90° of 5-mm width.

Intervention Type: PROCEDURE

Intrastromal corneal ring segment implantation (Tunnel)

Patients in this group are planned to undergo ICRS implantation through a femtosecond laser-assisted tunnel creation.

The device creates an intrastromal tunnel with a depth of nearly 80% of the corneal thickness at the site of implantation. The tunnel inner and outer diameters are at 5 and 6 mm from the corneal center, respectively with the incision located at the steepest keratometry axis.

Intervention Type: PROCEDURE

Eligibility Criteria

Inclusion Criteria

1. Patients with progressive keratoconus with maximum keratometry (Kmax) between 50-65 diopters

2. Central keratoconus (Keratoconus with steepest corneal point within the central 3 mm zone).

3. Clear corneal with a minimum pachymetry of 400 μm.

Exclusion Criteria

1. Corneal scars

2. Patients with advanced keratoconus with Kmax > 65 diopters.

3. Non-central keratoconus (para-central or peripheral keratoconus with steepest corneal point outside the central 3 mm zone).

4. Previous corneal cross-linking and/or ocular surgery.

5. Systemic diseases such as diabetes mellitus and autoimmune diseases

• Minimum Eligible Age: 18 Years
• Maximum Eligible Age: 35 Years
• Eligible Sex: ALL
• Accepts Healthy Volunteers: Yes

Sponsors

Assiut University

OTHER

Sponsor Role: lead

Responsible Party

Mahmoud Abdel-Radi

Principal Investigator

Responsibility Role: PRINCIPAL_INVESTIGATOR

Principal Investigators

Mahmoud Abdel-Radi, MD

Role: PRINCIPAL_INVESTIGATOR

Assiut University

Locations

Tiba Eye Center

Asyut, Asyut Governorate, Egypt

Countries

Egypt

References

Izquierdo L Jr, Rodriguez AM, Sarquis RA, Altamirano D, Henriquez MA. Intracorneal circular ring implant with femtosecond laser: Pocket versus tunnel. Eur J Ophthalmol. 2022 Jan;32(1):176-182. doi: 10.1177/1120672121994729. Epub 2021 Feb 12.

Reference Type: BACKGROUND

PMID: 33579160 (View on PubMed)

Other Identifiers

PVTICRS

Identifier Type: -

Identifier Source: org_study_id