Evaluation of the Change in the DA Ratio, IR and SSI as Parameters of Corneal Biomechanics Post Different LVC Procedures

Evaluation of the Change in the Deformation Amplitude Ratio, Integrated Radius and Stress Strain Index as Parameters of Corneal Biomechanics Post Different Laser Vision Correction Procedures

In the study, The Investigators will compare the participates' corneal biomechanical properties including:

Deformation Amplitude ratio (Da Ratio) Integrated Radius (IR) Stress strain index (SSI)

All measurements will be taken before and after 3 months of LVC.

Study Overview

• Status: Completed
• Conditions: Corneal Biomechanics
• Intervention / Treatment: Diagnostic test: CORVIS

Detailed Description

Each Participant will undergo preoperative pentacam and corvis scan for his eyes and the 3 months post operative.

The participants are divided into 3 groups, one who underwent LASIK, one PRK and one Femto LASIK.

Collected data will before and after surgery will be compared in each arm and then the 3 arms will be compared together.

• Study Type: Interventional
• Enrollment (Actual): 33
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Egypt
  • Cairo, Egypt
    • Cairo University

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years to 40 years (Adult)
• Accepts Healthy Volunteers: Yes
• Genders Eligible for Study: All

Description

Inclusion Criteria:

• • Age range 18 - 40 years.

  • Normal eyes with normal tomographic indices.
  • Patients with maximum mean refractive spherical equivalent (MRSE) of -7.00 diopters and with maximum astigmatism of -3.00 diopters.

Exclusion Criteria:

• • Patients with any other coexisting corneal diseases.

  • Keratoconus eyes.
  • Eyes with previous refractive corneal surgery.
  • Patients with increased intraocular pressure.

Study Plan

How is the study designed?

Design Details

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

Number of Arms

3

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Active Comparator: Laser In situ Keratomileusis (LASIK); Measurement of the deformation amplitude ratio, integrated radius and stress strain index as corneal biomechanical indices in refractive patients before and after LASIK	Diagnostic test: CORVIS; Measurement of the DA ratio, IR and SSI before and after for patients under gone LASIK, femto LASIK and PRK using the CORVIS device.
Active Comparator: Femto-second assisted LASIK (FS-LASIK); Measurement of the deformation amplitude ratio, integrated radius and stress strain index as corneal biomechanical indices in refractive patients before and after Femto LASIK	Diagnostic test: CORVIS; Measurement of the DA ratio, IR and SSI before and after for patients under gone LASIK, femto LASIK and PRK using the CORVIS device.
Active Comparator: Photorefractive Keratectomy (PRK); Measurement of the deformation amplitude ratio, integrated radius and stress strain index as corneal biomechanical indices in refractive patients before and after PRK	Diagnostic test: CORVIS; Measurement of the DA ratio, IR and SSI before and after for patients under gone LASIK, femto LASIK and PRK using the CORVIS device.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Evaluation of the changes in DA ratio, integrated radius and SSI before and after LVC	Comparison between in DA ratio (DA ratio) in patients undergoing LASIK, Femto LASIK and PRK. Comparison between changes in integrated Radius (IR) in patients undergoing LASIK, Femto LASIK and PRK. Comparison between changes in Stress strain index (SSI) in patients undergoing LASIK, Femto LASIK and PRK. Each indices will be compared before and after the Laser vision correction (LVC) procedure and the indices are not to be compared to each other to have have a fixed unit measure. I reviewed your comment and I dont see any conflicts, to clarify how multiple measurements will be aggregated to arrive at one reported value again I am going to measure each index and compare it with "itself' before and after 3 different LVC.	3-6 months post operative

Collaborators and Investigators

• Sponsor: Cairo University
• Investigators: Principal Investigator: Mohamed Hosny, Cairo University; Study Director: Mohamed Anis, Cairo University; Study Chair: Wessam Salem, Cairo University; Study Director: Mohamed ELnaggar, Research Institute of Ophthalmology

Study record dates

Study Major Dates

• Study Start (Actual): January 1, 2022
• Primary Completion (Actual): August 1, 2022
• Study Completion (Actual): January 30, 2023

Study Registration Dates

• First Submitted: May 1, 2022
• First Submitted That Met QC Criteria: May 12, 2022
• First Posted (Actual): May 17, 2022

Study Record Updates

• Last Update Posted (Estimate): February 21, 2023
• Last Update Submitted That Met QC Criteria: February 19, 2023
• Last Verified: February 1, 2023

More Information

Terms related to this study

• Keywords: CORVIS - Corneal Biomechanics
• Other Study ID Numbers: MD 187-2020

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No