Myoring Versus Keraring Implantation for Keratoconus

Phase 2

• Conditions: Keratoconus
• Interventions: Other: Intrastromal corneal continuous ring (Myoring) implantation; Other: intrastromal corneal ring segments (Keraring) implantation

• Registration Number: NCT01869517
• Lead Sponsor: Shahid Beheshti University of Medical Sciences

Brief Summary

Various approaches, including surgical and non-surgical management have been proposed for keratoconus. One of the surgical procedures is Intrastromal Corneal Ring implantations that have been designed to achieve refractive readjustment by flattening the cornea. There are different models of Intrastromal Corneal rings available: intrastromal corneal ring segments (ICRS) such as Keraring and intrastromal corneal continuous ring (ICCR) like Myoring.

Most studies of these two types of ring implantation outcomes are retrospective case series. Thus, this Randomized Clinical Trial study was designed with the aim of Comparing visual and refractive outcomes and complications of insertion Myoring versus Keraring using Femtosecond laser. Keratoconus patients with compound myopic astigmatism who meet the inclusion criteria will randomly allocated to the Keraring and Myoring groups. Subsequently, the clinical outcomes of two groups will be compared at one,3 and 6 months after surgery.

Detailed Description

Not available

Study Timeline

• Study Start: 2013-05
• Study First Submitted: 2013-05-22
• Status Verified: 2013-06
• Study First Submitted QC: 2013-06-01
• Last Update Submitted: 2013-06-01
• Study First Posted: 2013-06-05
• Last Update Posted: 2013-06-05
• Primary Completion: 2015-05

Recruitment & Eligibility

• Status: UNKNOWN
• Sex: All
• Target Recruitment: 23

Inclusion Criteria

• keratoconus patients and :
• age between 20 to 40
• corneal thickness> 380 microns
• mean keratometry between 44 to 60 D
• clear central cornea
• Patients should be discontinued their contact lenses for 3 weeks prior to the exams
• contact lenses in tolerance
• 20/200<visual acuity <20/30

Exclusion Criteria

• Positive pregnancy test
• Breast-feeding
• History of glaucoma, cataract, vernal and atopic keratoconjunctivitis
• History of previous ophthalmologic surgery, keratorefractive surgery on the operative eye
• Dry eye
• Corneal stromal disorders
• History of herpetic keratitis
• Pellucid marginal degeneration
• Corneal grafts
• Retinal disorders
• Nystagmus and uncooperative disposition
• Neuro-ophthalmologic disorders
• Intraocular pressure <10 mmHg or >21 mmHg
• Patients with autoimmune, connective tissue disorders, diabetes and immunosuppressive drugs users
• Hyperopia

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: PARALLEL

Arm && Interventions

Group	Intervention	Description
Intrastromal corneal continuous ring (Myoring)	Intrastromal corneal continuous ring (Myoring) implantation	-
Intrastromal corneal ring segments (Keraring)	intrastromal corneal ring segments (Keraring) implantation	-

Primary Outcome Measures

Name	Time	Method
uncorrected visual acuity	6 months	Snellen E chart

Secondary Outcome Measures

Name	Time	Method
Corneal thickness	6months	Galilei Dual Scheimpflug Analyzer ( Ziemer, Switzerland)
Corneal irregularities (3, 5 and 7 mm of central cornea)	6 months	Galilei Dual Scheimpflug Analyzer ( Ziemer, Switzerland)
Front & back corneal elevation	6 months	Galilei Dual Scheimpflug Analyzer ( Ziemer, Switzerland)
Corneal aberrometry	6 months	Galilei Dual Scheimpflug Analyzer ( Ziemer, Switzerland)
Corneal eccentricity	6 months	Galilei Dual Scheimpflug Analyzer ( Ziemer, Switzerland)
Corneal hysteresis & corneal resistance factor	6 months	Ocular response Analyzer (reichert ophthalmic instruments, Buffalo,New York; ,USA)
Intra and postoperative complications (glare, night vision problem, migration, extrusion, infection)	Intra and post operatien	clinical examination, patients history

Trial Locations

Locations (1)

Islamic Republic OF Iran; 🇮🇷 Tehran, Iran, Islamic Republic of