Clinical trial NCT06110286: Corneal High Order Aberrations After Stream Light and Mechanical Photorefractive Keratectomy
Official title: Comparison of Corneal High Order Aberrations After Stream Light Trans-PRK and Mechanical Photorefractive Keratectomy
Study type: OBSERVATIONAL
Overall status: RECRUITING
Conditions: Compare Corneal High Order Aberrations Before and After Stream Light Trans-PRK and Mechanical Photorefractive Keratectomy
Lead sponsor: Assiut University
Sponsor class: OTHER
First posted: 2023-10-31
Enrollment: 60
Sex: ALL
Minimum age (years): 20
Maximum age (years): 40
Standard ages: ADULT
Accepts healthy volunteers: no
Observational model: COHORT
Time perspective: PROSPECTIVE
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

Brief summary: 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

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.

Eligibility criteria: 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.

Primary outcomes:
measure: Corneal high order aberrations measured before and after the intervention by corneal topography machine
timeFrame: 1 monthe after surgery
Secondary outcomes:
Other outcomes:
Locations:
city: Assiut
country: Egypt
facility: Assiut university faculty of medicine
state: Assiut University
Study officials:
References: