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Completed

NCT Number: NCT07481227

FS-LASIK Versus TransPRK for Mixed Astigmatism

Mixed astigmatism is a type of refractive error in which the two principal steep and flat meridians focus the light in front and behind the retina, respectively.1 Laser vision correction (LVC) for mixed astigmatism is challenging as it involves a bitoric ablative pattern to flatten the steepest meridian and steepen the flattest one. The aim of the current study was to compare the visual and refractive outcomes of FS-LASIK versus single-step TransPRK for treatment of patients with mixed astigmatism.

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Key information

Conditions

Mixed Astigmatism Astigmatism Eye Diseases Refractive Errors

Age range

18 year–50 year

Sex eligibility

All sexes

Study type

Observational

Primary location

TIBA Eye Center

Asyut, Asyut Governorate, 71515, Egypt

Who can participate

Healthy volunteers accepted: No

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • Mixed astigmatism (Plus sphere up to +4 diopters D and a minus cylinder up to -6 D).
  • Stable refraction.
  • Clear cornea.
  • Normal corneal tomography.

Exclusion criteria

  • Corrected distance visual acuity worse than 20/32 Snellen's acuity.
  • Difference between manifest and cycloplegic refraction ≥ 1 D.
  • Previous corneal or ocular surgeries, other ocular diseases.
  • Systemic diseases including diabetes mellitus and autoimmune diseases.

Treatment and study plan

Femtosecond laser-assisted LASIK

Procedure

Patients in the FS-LASIK group underwent flap creation using the femtosecond laser WaveLight FS200® (Alcon lab, TX, USA). After flap creation, wave-front optimized stromal ablation was performed with WaveLight EX-500 (WaveLight®; Alcon Laboratories, Fort Worth, TX, USA) for mixed astigmatism correction.

Single-step transepithelial PRK

Procedure

Patients in the single-step TransPRK group underwent StreamLight® PRK in WaveLight EX-500 Excimer laser (WaveLight®; Alcon Laboratories, Fort Worth, TX, USA). In a single step, epithelial ablation (based on epithelial mapping) followed by stromal ablation for mixed astigmatism correction, were accomplished.

Primary outcomes

  1. Uncorrected distance visual acuity (UDVA)

    Time frame: 24 months

    Visual acuity measurement using Snellen's Acuity Chart converted to logMAR notation.

  2. Corrected distance visual acuity (CDVA)

    Time frame: 24 months

    Corrected visual acuity measurement using Snellen's Acuity Chart and converted to logMAR notation.

  3. Postoperative refraction

    Time frame: 24 months

    Manifest sphere and cylinder measured by Topcon Auto-Keratorefractometer

Sponsors and collaborators

Lead sponsor

Assiut University

Other

Registry information

Official study title

Comparative Study of Femtosecond Laser-assisted LASIK and Single-step Transepithelial Photorefractive Keratectomy for Correction of Mixed Astigmatism

Important dates

Study start
2019
Primary completion
2025
Study completion
2025
First posted
Mar 18, 2026
Registry last updated
Mar 18, 2026

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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