Pocket Versus Tunnel ICRS for Treatment of Keratoconus

Assiut University

Status: Completed

Conditions: Keratoconus

Treatments: Procedure: Intrastromal corneal ring segment implantation (Tunnel); Procedure: Intrastromal corneal ring segment implantation (Pocket)

Study type: Interventional

Funder types: Other

Identifiers

NCT05748847

PVTICRS

Details and patient eligibility

About

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.

Full 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

Enrollment: 74 patients

Sex: All

Ages: 18 to 35 years old

Volunteers: Accepts Healthy Volunteers

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

Trial design

Primary purpose: Treatment

Allocation: Randomized

Interventional model: Parallel Assignment

Masking: Single Blind

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74 participants in 2 patient groups

Pocket ICRS

Active Comparator group

Description:

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

Treatment:

Procedure: Intrastromal corneal ring segment implantation (Pocket)

Tunnel ICRS

Active Comparator group

Description:

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.

Treatment:

Procedure: Intrastromal corneal ring segment implantation (Tunnel)