NCT06818461

Brief Summary

To evaluate corneal biomechanical changes using the Corvis ST and ECD in patients who have under-gone LASIK, PRK, corneal cross-linking (CXL), Veriflex IOL and ICL.

Trial Health

87
On Track

Trial Health Score

Automated assessment based on enrollment pace, timeline, and geographic reach

Enrollment
150

participants targeted

Target at P50-P75 for all trials

Timeline
Completed

Started Jan 2025

Shorter than P25 for all trials

Geographic Reach
1 country

1 active site

Status
completed

Health score is calculated from publicly available data and should be used for screening purposes only.

Trial Relationships

Click on a node to explore related trials.

Study Timeline

Key milestones and dates

Study Start

First participant enrolled

January 1, 2025

Completed
1 month until next milestone

First Submitted

Initial submission to the registry

February 5, 2025

Completed
5 days until next milestone

First Posted

Study publicly available on registry

February 10, 2025

Completed
5 months until next milestone

Primary Completion

Last participant's last visit for primary outcome

June 28, 2025

Completed
4 months until next milestone

Study Completion

Last participant's last visit for all outcomes

October 31, 2025

Completed
Last Updated

July 2, 2026

Status Verified

July 1, 2026

Enrollment Period

6 months

First QC Date

February 5, 2025

Last Update Submit

July 1, 2026

Conditions

MyopiaKeratoconusRefractive Surgery

Keywords

corneal biomechanicsprklasikcxl

Outcome Measures

Primary Outcomes (2)

  • corneal biomechanics

    6 month

  • ECD measuments

    corneal endothelial cell count measurments

    Preoperative and 6 month postoperative

Study Arms (4)

Lasik

a non-contact air puff tonometer combined with Scheimpflug imaging to assess the cornea's deformation response. Measurements will be taken at multiple postoperative time points to track biomechanical changes. Key parameters such as Deformation Amplitude (DA), Stiffness Parameter (SP-A1), Applanation Times (A1 \& A2), Peak Distance (PD), and Biomechanically Corrected IOP (bIOP) will be recorded.

Other: Corvis St Before and after lasik, PRK, CXL, Veriflex IOL and ICL

PRK

a non-contact air puff tonometer combined with Scheimpflug imaging to assess the cornea's deformation response. Measurements will be taken at multiple postoperative time points to track biomechanical changes. Key parameters such as Deformation Amplitude (DA), Stiffness Parameter (SP-A1), Applanation Times (A1 \& A2), Peak Distance (PD), and Biomechanically Corrected IOP (bIOP) will be recorded.

Other: Corvis St Before and after lasik, PRK, CXL, Veriflex IOL and ICL

CXL

a non-contact air puff tonometer combined with Scheimpflug imaging to assess the cornea's deformation response. Measurements will be taken at multiple postoperative time points to track biomechanical changes. Key parameters such as Deformation Amplitude (DA), Stiffness Parameter (SP-A1), Applanation Times (A1 \& A2), Peak Distance (PD), and Biomechanically Corrected IOP (bIOP) will be recorded.

Other: Corvis St Before and after lasik, PRK, CXL, Veriflex IOL and ICL

Veriflex and ICL

corneal Biomechanics and ECD measuments pre and postoperative . a non-contact air puff tonometer combined with Scheimpflug imaging to assess the cornea's deformation response. Measurements will be taken at multiple postoperative time points to track biomechanical changes. Key parameters such as Deformation Amplitude (DA), Stiffness Parameter (SP-A1), Applanation Times (A1 \& A2), Peak Distance (PD), and Biomechanically Corrected IOP (bIOP) will be recorded.

Interventions

Corvis St Before and after lasik, PRK, CXL, Veriflex IOL and ICLOTHER

corneal biomechanics measurment using corvis St and corneal endothelial cell counts

CXLLasikPRK

Eligibility Criteria

Age18 Years - 60 Years
Sexall
Healthy VolunteersYes
Age GroupsAdult (18-64)
Sampling MethodProbability Sample
Study Population

patients coming for refractive surgery

You may qualify if:

  • \- 1. Adults aged 18-60 years. 2. Patients who have undergone LASIK, PRK, or CXL at least 1 month prior to measure-ment.
  • \. Stable refraction for at least 3 months post-procedure. 4. No evidence of active ocular disease or infection.

You may not qualify if:

  • \. History of other ocular surgeries (excluding LASIK, PRK, or CXL). 2. Presence of keratoconus or other corneal ectatic disorders not treated with CXL.
  • \. Systemic or ocular conditions affecting corneal biomechanical properties (e.g., dia-betes, connective tissue disorders).
  • \. Current or recent use of medications influencing corneal biomechanics.

Contact the study team to confirm eligibility.

Sponsors & Collaborators

Study Sites (1)

Clearvision

Mohandessin, Giza Governorate, 11344, Egypt

Location

Related Publications (3)

  • Saif PS, Okasha MG, Mahmoud H, Samir A, Abdelmonagy Ibrahim M. Impact of veriflex and ICL on corneal biomechanics and endothelial cell density. Sci Rep. 2025 Aug 27;15(1):31553. doi: 10.1038/s41598-025-14330-3.

    PMID: 40866426BACKGROUND

  • Saif PS, Saif MYS, Abdel Dayem HMK, Elsayed MOA, Ibrahim MAM. Assessment of corneal biomechanical properties using Corvis ST following LASIK, PRK, and CXL. Lasers Med Sci. 2026 Apr 16;41(1):73. doi: 10.1007/s10103-026-04858-9.

    PMID: 41986537BACKGROUND

  • Luce DA. Determining in vivo biomechanical properties of the cornea with an ocular response analyzer. J Cataract Refract Surg. 2005 Jan;31(1):156-62. doi: 10.1016/j.jcrs.2004.10.044.

    PMID: 15721708BACKGROUND

MeSH Terms

Conditions

MyopiaKeratoconus

Condition Hierarchy (Ancestors)

Refractive ErrorsEye DiseasesCorneal Diseases

Study Design

Study Type
observational
Observational Model
CASE CONTROL
Time Perspective
PROSPECTIVE
Sponsor Type
OTHER
Responsible Party
PRINCIPAL INVESTIGATOR
PI Title
Professour of Ophthalmology

Study Record Dates

First Submitted

February 5, 2025

First Posted

February 10, 2025

Study Start

January 1, 2025

Primary Completion

June 28, 2025

Study Completion

October 31, 2025

Last Updated

July 2, 2026

Record last verified: 2026-07

Locations

EG(1)