Accuracy of LASIK Flaps Created With the LenSx® Femtosecond Laser – A Pilot Study

Overview

The purpose of this study is to evaluate the thickness accuracy of Laser-assisted in situ keratomileusis (LASIK) flaps created with the LenSx® Laser.

Full Title of Study: “Accuracy of LASIK Flaps Created With the LenSx® Femtosecond Laser – A Pilot Study”

Study Type

  • Study Type: Interventional
  • Study Design
    • Allocation: N/A
    • Intervention Model: Single Group Assignment
    • Primary Purpose: Treatment
    • Masking: None (Open Label)
  • Study Primary Completion Date: April 9, 2016

Interventions

  • Device: Femtosecond Laser System
    • Used for the creation of a corneal flap in patients undergoing LASIK surgery
  • Procedure: LASIK surgery

Arms, Groups and Cohorts

  • Experimental: LenSx
    • LASIK surgery in both eyes using LenSx® Femtosecond Laser System

Clinical Trial Outcome Measures

Primary Measures

  • Flap Thickness Accuracy Within the Central Zone at Month 3 Postoperative
    • Time Frame: Month 3 postoperative
    • Flap thickness was assessed by optical coherence tomography (OCT) and averaged from 3 separate scans. Flap thickness accuracy was defined as the mean difference between the achieved and desired (desired subtracted from achieved) flap thickness. A positive number represents a postoperative flap thickness that is thicker than the expected flap thickness and vice versa for a negative number. Each eye contributed separately to the analysis.

Secondary Measures

  • Flap Thickness Accuracy Within the Central Zone at Month 1 Postoperative
    • Time Frame: Month 1 postoperative
    • Flap thickness was assessed by OCT and averaged from 3 separate scans. Flap thickness accuracy was defined as the mean difference between the achieved and desired (desired subtracted from achieved) flap thickness. A positive number represents a postoperative flap thickness that is thicker than the expected flap thickness and vice versa for a negative number. Each eye contributed separately to the analysis.
  • Flap Thickness Precision Within the Central Zone at Month 1 and Month 3 Postoperative
    • Time Frame: Month 1, Month 3 postoperative
    • Flap thickness was assessed by OCT and averaged from 3 separate scans. Flap thickness precision (variability of the achieved flap thickness) was defined as the standard deviation of the flap thickness measurement. Each eye contributed separately to the analysis.
  • Ease of Flap Dissection at Day 0, Operative Day
    • Time Frame: Day 0, operative day
    • Ease of flap dissection (ease of lifting the flap during surgery) was assessed on a scale from 0 to 5 where 0 = Unable to lift flap and 5 = Able to lift flap without any resistance using blunt instrument. Each eye contributed separately to the analysis.
  • Stromal Bed Quality at Day 0, Operative Day
    • Time Frame: Day 0, operative day
    • Stromal bed quality was assessed by the investigator on a roughness scale from 0 to 5 where 0 = Very rough surface and 5 = Very smooth surface. Each eye contributed separately to the analysis.
  • Opaque Bubble Layer (OBL) at Day 0, Operative Day
    • Time Frame: Day 0, operative day
    • Opaque bubble layer was assessed by the investigator during the surgery on a scale from 0 to 5 where 0 = No OBL and 5 = 100% OBL in the stromal bed area. Each eye contributed separately to the analysis.
  • Uncorrected Distance Visual Acuity (UCDVA) at Month 1 and Month 3 Postoperative
    • Time Frame: Month 1, Month 3 postoperative
    • UCDVA (measurement of uncorrected (without spectacles or other visual corrective devices) distance visual acuity) was assessed at a distance of 6 meters or 20 feet using a standard Snellen eye chart, both monocularly and binocularly, and reported categorically as a percentage of eyes analyzed.
  • Best Corrected Distance Visual Acuity (BCDVA) by Visit
    • Time Frame: Baseline, Month 1, Month 3 postoperative
    • BCDVA (measurement with the participant’s best spectacle correction) was assessed at a distance of 6 meters or 20 feet using a standard Snellen eye chart, both monocularly and binocularly, and reported categorically as a percentage of eyes analyzed.
  • Manifest Refraction Spherical Equivalent (MRSE)
    • Time Frame: Baseline, Month 1, Month 3 postoperative
    • The participant was manually refracted to his/her best correction using a phoropter and standard Snellen eye charts. Each eye contributed separately to the analysis.
  • Prediction Error Between Target Versus Achieved Refraction at One and Three Months Post-op
    • Time Frame: Month 1, Month 3 postoperative
    • Prediction error was summarized as a percentage of eyes within 0.5 D and 1.0 D of target at one and three months postoperative

Participating in This Clinical Trial

Inclusion Criteria

  • Diagnosed with myopia or hyperopia and eligible for femtosecond laser initiated LASIK surgery; – Best corrected visual acuity (BCVA) correctable to at least 20/25 in each eye; – If contact lens wearer, willing to discontinue contact lens wear prior to screening procedures; – Willing and able to return for ALL scheduled follow-up examinations; – Willing and able to provide written informed consent; – Eligible for bilateral LASIK procedures to be done on the same day; – Other protocol-specified inclusion criteria may apply. Exclusion Criteria:

  • Previous corneal surgery, corneal lesions that will impede laser treatment, corneal edema, hypotony, glaucoma, existing corneal implant, or keratoconus; – Known sensitivity to planned study concomitant medications; – Participation in any other ophthalmic drug or device clinical study for 30 days prior to or during the time of participation in this study; – Irregular astigmatism, based on the Investigator's judgement; – Pregnant, lactating or planning to become pregnant during the course of the study; – Other protocol-specified exclusion criteria may apply.

Gender Eligibility: All

Minimum Age: 22 Years

Maximum Age: N/A

Are Healthy Volunteers Accepted: No

Investigator Details

  • Lead Sponsor
    • Alcon Research
  • Provider of Information About this Clinical Study
    • Sponsor
  • Overall Official(s)
    • Clinical Trial Manager, GCRA, Study Director, Alcon, A Novartis Division

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