compare the efficacy, safety and predictability of corneal wavefront guided (WFG) and aberration free ablation in single-step transepithelial photorefractive keratectomy (TransPRK) in myopic patients with high pre-existing corneal higher order aberrations (HOAs).

Objectives:to compare the efficacy, safety and predictability of corneal wavefront guided (WFG) and aberration free ablation in single-step transepithelial photorefractive keratectomy (TransPRK) in myopic patients with high pre-existing corneal higher order aberrations (HOAs).

Background: Corneal WFG and aberration free treatments have been proposed as methods to achieve better visual, refractive, and optical outcomes.

Methods: prospective case series was conducted in El-Hekma Eye-LASIK center, Menoufia governorate, Egypt during the period from January 2017 to December 2017. TransPRK was performed to eligible myopic patients with or without astigmatism with corneal HOAs ≥ 0.35 µ utilizing either aberration free or corneal WFG patterns provided by ORKCAM software (SCHWIND eye-tech-solutions, Kleinostheim, Germany). Uncorrected distance visual acuity (UDVA), manifest and cycloplegic refractions, best spectacle corrected distance visual acuity (CDVA), thorough slit lamp examination and corneal topography were assessed and repeated six months postoperatively.

Inclusion Criteria:

• Myopic patients with or without astigmatism

Exclusion Criteria:

• severe dry eye,
• blepharitis,
• corneal disease,
• contact lens warpage,
• cataract,
• uveitis
• posterior segment anomalies involving the macula or optic nerve
• systemic conditions; diabetes mellitus, connective tissue disease, pregnancy or nursing. Also, any patient who had previous ocular surgery including keratorefractive surgery was excluded

patients 21 years or older with stable refraction for more than 1 year