Myoring Versus Keraring Implantation for Keratoconus

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.

Study Overview

• Status: Unknown
• Conditions: Keratoconus
• Intervention / Treatment: Other: Intrastromal corneal continuous ring (Myoring) implantation; Other: intrastromal corneal ring segments (Keraring) implantation

• Study Type: Interventional
• Enrollment: 23
• Phase: Phase 2

Contacts and Locations

Study Locations

• Iran, Islamic Republic of
  • Tehran, Iran, Islamic Republic of
    • Recruiting
    • Islamic Republic of Iran
    • Contact: Alireza Baradaran-Rafii; Phone Number: 009822591616; Email: labbafi@hotmail.com

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 20 years to 40 years (Adult)
• Accepts Healthy Volunteers: N/A
• Genders Eligible for Study: All

Description

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 Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Active Comparator: Intrastromal corneal continuous ring (Myoring)	Other: Intrastromal corneal continuous ring (Myoring) implantation
Active Comparator: Intrastromal corneal ring segments (Keraring)	Other: intrastromal corneal ring segments (Keraring) implantation

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
uncorrected visual acuity	Snellen E chart	6 months

Secondary Outcome Measures

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

Collaborators and Investigators

• Sponsor: Shahid Beheshti University of Medical Sciences

Study record dates

Study Major Dates

• Study Start: May 1, 2013
• Primary Completion (Anticipated): May 1, 2015

Study Registration Dates

• First Submitted: May 22, 2013
• First Submitted That Met QC Criteria: June 1, 2013
• First Posted (Estimate): June 5, 2013

Study Record Updates

• Last Update Posted (Estimate): June 5, 2013
• Last Update Submitted That Met QC Criteria: June 1, 2013
• Last Verified: June 1, 2013

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Eye Diseases; Corneal Diseases; Keratoconus
• Other Study ID Numbers: 91138