Comparison of Corneal Stromal Tissue Consumption (LATAC) (LATAC)

Comparison of Corneal Stromal Tissue Consumption Values Estimated When Programming the Intervention Versus the Values Measured by Pre and Postoperative Topography

In refractive surgery, stromal ablation depth is fundamental because it determines the thickness of the residual posterior wall. The posterior wall is an essential element that guarantees the refractive stability and the long term prevention of corneal ectasia after corneal refractive surgery. A minimum thickness of more or less 300 microns is universally accepted. Its calculation is based on well-known formulas, such as Munnerlynn ones.

With the excimer laser platform last generation WaveLight® Allegretto® EX-500 of Alcon, a new treatment option called "wavefront optimized" is offered for myopia, astigmatism and hyperopia. The ablation profile has been developed to save stromal tissue consumption and to favor the quality of vision, by optimizing connections between the optical zone and the transition zone of the photoablation. Alongside the theoretical formulas, evaluation of the depth of ablation may be defined by differential ultrasonic pachymetry or by topographical analysis pre and postoperatively. The latter is currently the method of reference to assess the corneal thickness.

Study Overview

• Status: Completed
• Conditions: Disorders, Refractive
• Intervention / Treatment: Device: Measurement of stromal tissue ablation

• Study Type: Observational
• Enrollment (Actual): 50

Contacts and Locations

Study Locations

• France
  • Paris, France, 75019
    • Fondation ophtalmique Adolphe de Rothschild

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years and older (Adult, Older Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

• Sampling Method: Non-Probability Sample

Study Population

Patients having a refractive disorder and for whom a refractive surgery by LASIK is programmed.

Description

Inclusion Criteria:

• Patients having a refractive disorder and for whom a refractive surgery is programmed.

Exclusion Criteria:

• Patient opposed to participation in the study
• Another refractive surgery technique
• Hyperopic patient
• Pregnant or lactating woman
• Patient under a measure of legal protection
• Absence of affiliation to social security or universal health coverage (CMU)

Study Plan

How is the study designed?

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Difference between stromal tissue consumption, expressed in micrometers, estimated before surgery by WaveLight Allegretto EX-500 laser and measured one month after surgery by Pentacam	Stromal tissue consumption will be estimated preoperatively by WaveLight Allegretto EX-500 laser and central corneal thickness will be measured by Pentacam. One month after refractive surgery, during follow-up,central corneal thickness will be again measured by Pentacam. The difference between the estimated and the measured tissue consumption will be calculated.	One month

Collaborators and Investigators

• Sponsor: Fondation Ophtalmologique Adolphe de Rothschild

Study record dates

Study Major Dates

• Study Start (Actual): August 8, 2015
• Primary Completion (Actual): January 18, 2017
• Study Completion (Actual): March 15, 2017

Study Registration Dates

• First Submitted: August 4, 2015
• First Submitted That Met QC Criteria: August 10, 2015
• First Posted (Estimate): August 11, 2015

Study Record Updates

• Last Update Posted (Actual): March 20, 2017
• Last Update Submitted That Met QC Criteria: March 17, 2017
• Last Verified: March 1, 2017

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Eye Diseases; Refractive Errors
• Other Study ID Numbers: JFO_2015_26