Corneal High Order Aberrations After Stream Light and Mechanical Photorefractive Keratectomy

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: Recruiting
• Conditions: Compare Corneal High Order Aberrations Before and After Stream Light Trans-PRK and Mechanical Photorefractive Keratectomy
• Intervention / Treatment: Other: Photorefractive keratectomy

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: Observational
• Enrollment (Estimated): 60

Contacts and Locations

• Study Contact: Name: Esraa R Mokhtar, Master; Phone Number: 01064021834; Email: esraarifaat89@gmail.com
• Study Contact Backup: Name: Khaled A Mohamed, MD; Phone Number: 01123869699; Email: abdelazeem..kh@gmil.com

Study Locations

• Egypt
  • Assiut University
    • Assiut, Assiut University, Egypt, 71515
      • Recruiting
      • Assiut university faculty of medicine
      • Contact: Esraa R Mokhtar, Master; Phone Number: 01064021834; Email: esraarifaat89@gmail.com
      • Contact: Khaled A Mohamed, MD; Phone Number: 01114001717; Email: abdelazeem..kh@gmil.com

Participation Criteria

Eligibility Criteria

• 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

How is the study designed?

Number of groups / cohorts

2

Cohorts and Interventions

Group / Cohort	Intervention / Treatment
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

Outcome Measure	Measure Description	Time Frame
Corneal high order aberrations measured before and after the intervention by corneal topography machine	Third order aberrations; Trefoil and coma aberrations; Forth order aberrations; spherical aberrations Trefoil, spherical and coma aberrations	1 monthe after surgery

Collaborators and Investigators

• Sponsor: Assiut University

Study record dates

Study Major Dates

• Study Start (Estimated): November 1, 2023
• Primary Completion (Estimated): October 1, 2024
• Study Completion (Estimated): October 1, 2025

Study Registration Dates

• First Submitted: October 26, 2023
• First Submitted That Met QC Criteria: October 26, 2023
• First Posted (Actual): October 31, 2023

Study Record Updates

• Last Update Posted (Actual): October 31, 2023
• Last Update Submitted That Met QC Criteria: October 26, 2023
• Last Verified: October 1, 2023

More Information

Terms related to this study

• Other Study ID 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