Clinical Trial of the Femtosecond Laser System VisuMax for Refractive Correction of Hyperopia by Means of Lenticule Extraction

April 24, 2018 updated by: Tilganga Institute of Ophthalmology

This is a feasibility and clinical evaluation study of the VisuMax femtosecond laser for refractive correction of hyperopia using the small incision lenticule extraction (ReLEx smile) method.

In ReLEx® the VisuMax femtosecond laser creates two interfaces that define a refractive lenticule of stromal tissue. In ReLEx® FLEx, the upper interface is converted into a LASIK flap by the creation of a sidecut. The LASIK flap is lifted and the lenticule can be removed to correct the refractive error by tissue subtraction. In ReLEx® smile, the lenticule is dissected and removed through a small 2-3mm incision without the need to create a whole flap.

The aims are i) to optimize the VisuMax settings for lenticule separation ii) to optimize the lenticule geometry iii) to assess the safety, efficacy and stability of the treatment

Study Overview

Status

Unknown

Conditions

Intervention / Treatment

Study Type

Interventional

Enrollment (Anticipated)

220

Phase

  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact Backup

Study Locations

  • Nepal
      • Kathmandu, Nepal
        • Recruiting
        • Tilganga Institute of Ophthalmology, Refractive Surgery Unit
        • Contact:

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

21 years and older (Adult, Older Adult)

Accepts Healthy Volunteers

No

Genders Eligible for Study

All

Description

Inclusion Criteria:

  • older than 21 years of age,
  • maximum hyperopic meridian between +1.00D and +7.00D
  • astigmatism up to 6D

  • CDVA of:

    1. 20/200 or worse in the eye(s) being treated for Phase I
    2. Between 20/200 and 20/100 in the eye(s) being treated for Phase II
    3. Between 20/40 and 20/60 in the eye(s) being treated for Phase III
    4. 20/25 or better for Phase IV
  • total uncut stromal thickness of more than 300 µm
  • no previous refractive surgery,
  • no ocular disease,
  • normal corneal topography,
  • contact lens wearers have to stop wearing hard contact lenses at least 4 weeks and soft contact lenses 2 weeks prior to pre-examination,
  • willing to attend follow-up examinations within the scope of the clinical investigation,
  • able and willing to sign the informed consent

Exclusion Criteria:

  • patients who are not being able to lie flat in a horizontal position,
  • patients who are not being able to understand and give informed consent,
  • pregnant or nursing women (or women who are planning to became pregnant during the clinical investigation),
  • diagnosis of an autoimmune disease (e.g. AIDS), connective tissue disease or diabetes,
  • treatment with medications such as steroids or immune-suppressants,
  • herpes simplex or herpes zoster keratitis,
  • all standard medical exclusion criteria for LASIK

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: N/A
  • Interventional Model: Single Group Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: Small incision lenticule extraction
Small incision lenticule extraction (SMILE) is a form of corneal laser refractive surgery performed using a femtosecond laser
Procedure: Small incision lenticule extraction
The VisuMax femtosecond laser is used to create two interfaces that define a refractive lenticule of stromal tissue and a 2mm wide tunnel to connect the upper layer to the corneal surface. The lenticule is manually dissected and removed through the small 2mm incision without the need to create a flap as in LASIK.
Other Names:
  • SMILE
  • Refractive lenticule extraction
  • ReLEx
Device: ReLEx® (SMILE)

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Safety of corrected distance visual acuity (change in corrected distance visual acuity)
Time Frame: 1 year
Assess the change in corrected distance visual acuity (CDVA) before and after the SMILE procedure.
1 year
Efficacy of uncorrected distance visual acuity (uncorrected distance visual acuity achieved after the SMILE procedure relative to the preoperative CDVA)
Time Frame: 1 year
Measure the uncorrected distance visual acuity achieved after the SMILE procedure relative to the preoperative CDVA for all eyes where the intended target refraction was emmetropia.
1 year
Predictability of refractive outcome ( change in manifest refractive error)
Time Frame: 1 year
Measure the change in manifest refractive error (sphere, cylinder, spherical equivalent) after the SMILE procedure and analyze the predictability relative to the intended target refraction as well as the refractive stability over the 1 year follow-up period
1 year

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Optical zone centration (Measure the achieved centration of the optical zone)
Time Frame: 1 year
Measure the achieved centration of the optical zone by topography relative to the corneal vertex (the intended treatment center)
1 year
Optical zone diameter
Time Frame: 1 year
Measure the achieved optical zone diameter from tangential curvature difference maps relative to the intended optical zone
1 year

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Tilganga Institute of Ophthalmology

Collaborators

London Vision Clinic

Investigators

  • Principal Investigator: Kishore R Pradhan, MD, Tilganga Institute of Ophthalmology

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start

January 1, 2014

Primary Completion (Anticipated)

December 1, 2018

Study Registration Dates

First Submitted

December 9, 2014

First Submitted That Met QC Criteria

December 11, 2014

First Posted (Estimate)

December 12, 2014

Study Record Updates

Last Update Posted (Actual)

April 25, 2018

Last Update Submitted That Met QC Criteria

April 24, 2018

Last Verified

April 1, 2018

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • 177/2013

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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