Corneal High Order Aberrations After Stream Light and Mechanical Photorefractive Keratectomy

October 26, 2023 updated by: Khaled Abdelazeem, Assiut University

Comparison of Corneal High Order Aberrations After Stream Light Trans-PRK and Mechanical Photorefractive Keratectomy

Compare corneal high order aberrations before and after stream light trans-PRK and mechanical photorefractive keratectomy including third order aberrations; Trefoil and coma aberrations and forth order aberrations; spherical aberrations

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Recruiting

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Detailed Description

Laser technology has played an important role in promoting the development of ophthalmology, especially corneal refractive surgery.1 Trans-epithelial photorefractive keratectomy (Trans-PRK) has become a highly researched topic in recent years.2 Different epithelial debridement methods with PRK showed favorable results for the surgical treatment of low to moderate myopia3. In mechanical PRK (m-PRK), epithelial debridement is achieved using a blunt spatula, whereas in stream light trans-PRK (t-PRK), there after an excimer laser is used to ablate corneal stroma3. The Stream Light t-PRK is a safe and effective treatment option for the correction of low to moderate myopia.4 Many studies have shown that the corneal asphericity developed significantly after refractive surgeries and introduce higher-order aberrations (HOAs).2 The present study focused on three of the most clinically important HOAs; spherical, coma, and trefoil aberrations, both preoperative and postoperative were recorded from topography over the 6-mm-diameter central corneal zone using Pentacam.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Observational

Enrollment (Estimated)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
60

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact

The name and contact information for the person who can answer enrollment questions for a clinical study. Each location where the study is being conducted may also have a specific contact, who may be better able to answer those questions.

Study Contact Backup

Study Locations

  • Egypt
    • Assiut University
      • Assiut, Assiut University, Egypt, 71515

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

  • Adult

Accepts Healthy Volunteers

No

Sampling Method

Probability Sample

Study Population

Myopic patients with spherical equivalent not more than -6D who will present to refractive surgery Centre in Assiut and seeking for refractive surgery to get rid of their glasses and fulfilling the inclusion and exclusion criteria

Description

Inclusion Criteria:

  • • Stable refraction for 1 year (refraction does not exceed 1D more than the last prescribed glasses).

    • Discontinuation of soft contact lens wears at least 1 week before examination.
    • Topography criteria:
  • Corneal thickness equal or more than 470 um
  • Symmetrical bow-tie
  • Back elevation not more than +12
  • Normal Belin\Ambrosio Enhanced ectasia display
  • Spherical equivalent not more than -6D.

Exclusion Criteria:

  • • Previous ocular surgery

    • Concurrent ocular pathology; corneal scar, corneal dystrophy
    • Systemic disease; Uncontrolled diabetes, collagen disease
    • Post-operative complications; sub-epithelial haze.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

Cohorts and Interventions

Group / Cohort

Group / Cohort

A group or subgroup of participants in an observational study that is assessed for biomedical or health outcomes.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Mechanical photorefractive keratectomy
Laser photorefractive keratecyomy by Ex500 excimer laser after mannual removal of corneal epithelium
Other: Photorefractive keratectomy
Laser keratectomy by EX500 excimer laser after removal of corneal epithelium either mannually or by laser ablation
Stream light trans-PRK
Laser photorefractive keratectomy by Ex500 excimer laser after removal of corneal epithelium by stream-light laser technique
Other: Photorefractive keratectomy
Laser keratectomy by EX500 excimer laser after removal of corneal epithelium either mannually or by laser ablation

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
Corneal high order aberrations measured before and after the intervention by corneal topography machine
Time Frame: 1 monthe after surgery
  • Third order aberrations; Trefoil and coma aberrations
  • Forth order aberrations; spherical aberrations Trefoil, spherical and coma aberrations
1 monthe after surgery

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
Assiut University

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Estimated)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
November 1, 2023

Primary Completion (Estimated)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
October 1, 2024

Study Completion (Estimated)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
October 1, 2025

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
October 26, 2023

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
October 26, 2023

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
October 31, 2023

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
October 31, 2023

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
October 26, 2023

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
October 1, 2023

More Information

Terms related to this study

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • 1799

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

product manufactured in and exported from the U.S.

Yes

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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