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

Not Applicable

Completed

• Conditions: Corneal Biomechanics
• Interventions: Diagnostic Test: CORVIS

• Registration Number: NCT05377099
• Lead Sponsor: Cairo University

Brief Summary

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.

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 Timeline

• Study Start: 2022-01-01
• Study First Submitted: 2022-05-01
• Study First Submitted QC: 2022-05-12
• Study First Posted: 2022-05-17
• Primary Completion: 2022-08-01
• Study Completion: 2023-01-30
• Status Verified: 2023-02
• Last Update Submitted: 2023-02-19
• Last Update Posted: 2023-02-21

Recruitment & Eligibility

• Status: COMPLETED
• Sex: All
• Target Recruitment: 33

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 & Design

• Study Type: INTERVENTIONAL
• Study Design: PARALLEL

Arm && Interventions

Group	Intervention	Description
Photorefractive Keratectomy (PRK)	CORVIS	Measurement of the deformation amplitude ratio, integrated radius and stress strain index as corneal biomechanical indices in refractive patients before and after PRK
Femto-second assisted LASIK (FS-LASIK)	CORVIS	Measurement of the deformation amplitude ratio, integrated radius and stress strain index as corneal biomechanical indices in refractive patients before and after Femto LASIK
Laser In situ Keratomileusis (LASIK)	CORVIS	Measurement of the deformation amplitude ratio, integrated radius and stress strain index as corneal biomechanical indices in refractive patients before and after LASIK

Primary Outcome Measures

Name	Time	Method
Evaluation of the changes in DA ratio, integrated radius and SSI before and after LVC	3-6 months post operative	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.

Trial Locations

Locations (1)

Cairo University; 🇪🇬 Cairo, Egypt