Clinical trial NCT02316041: Clinical Trial of the Femtosecond Laser System VisuMax for Refractive Correction of Hyperopia by Means of Lenticule Extraction
Official title: Clinical Trial of the Femtosecond Laser System VisuMax for Refractive Correction of Hyperopia by Means of Lenticule Extraction
Study type: INTERVENTIONAL
Overall status: UNKNOWN
Phase: NA
Conditions: Hyperopia
Keywords: Femtosecond laser
Small incision lenticule extraction (SMILE)
Lead sponsor: Tilganga Institute of Ophthalmology
Sponsor class: OTHER
Collaborators: name: London Vision Clinic
First posted: 2014-12-12
Enrollment: 220
Sex: ALL
Minimum age (years): 21
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: yes
Allocation: NA
Intervention model: SINGLE_GROUP
Primary purpose: TREATMENT

Brief summary: 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


Eligibility criteria: 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

Primary outcomes:
measure: Safety of corrected distance visual acuity (change in corrected distance visual acuity)
timeFrame: 1 year
measure: Efficacy of uncorrected distance visual acuity (uncorrected distance visual acuity achieved after the SMILE procedure relative to the preoperative CDVA)
timeFrame: 1 year
measure: Predictability of refractive outcome ( change in manifest refractive error)
timeFrame: 1 year
Secondary outcomes:
measure: Optical zone centration (Measure the achieved centration of the optical zone)
timeFrame: 1 year
measure: Optical zone diameter
timeFrame: 1 year
Other outcomes:
Locations:
city: Kathmandu
country: Nepal
facility: Tilganga Institute of Ophthalmology, Refractive Surgery Unit
Study officials:
affiliation: Tilganga Institute of Ophthalmology
name: Kishore R Pradhan, MD
role: PRINCIPAL_INVESTIGATOR
References:
citation: Blum M, Kunert KS, Vossmerbaumer U, Sekundo W. Femtosecond lenticule extraction (ReLEx) for correction of hyperopia - first results. Graefes Arch Clin Exp Ophthalmol. 2013 Jan;251(1):349-55. doi: 10.1007/s00417-012-2064-y. Epub 2012 Jun 14.