FS-LASIK Versus TransPRK for Mixed Astigmatism

March 15, 2026 updated by: Mahmoud Abdel-Radi, Assiut University

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

Study Overview

Status

Completed

Conditions

Intervention / Treatment

Study Type

Observational

Enrollment (Actual)

39

Contacts and Locations

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

Study Locations

  • Egypt
    • Asyut Governorate
      • Asyut, Asyut Governorate, Egypt, 71515
        • TIBA Eye Center

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

Ages Eligible for Study

  • Adult

Accepts Healthy Volunteers

No

Sampling Method

Probability Sample

Study Population

This was a retrospective comparative study conducted at Tiba eye center (private practice).

The study reviewed and analyzed the records of patients with mixed astigmatism who underwent femtosecond laser-assisted LASIK (FS-LASIK group) or single-step TransPRK (TransPRK group) and completed 24 months of follow-up.

Description

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.

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
Intervention / Treatment
Femtosecond laser-assisted laser in situ keratomileusis (FS-LASIK) group
Procedure: Femtosecond laser-assisted LASIK
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 photorefractive keratectomy (TransPRK) group
Procedure: Single-step transepithelial PRK
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.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Uncorrected distance visual acuity (UDVA)
Time Frame: 24 months
Visual acuity measurement using Snellen's Acuity Chart converted to logMAR notation.
24 months
Corrected distance visual acuity (CDVA)
Time Frame: 24 months
Corrected visual acuity measurement using Snellen's Acuity Chart and converted to logMAR notation.
24 months
Postoperative refraction
Time Frame: 24 months
Manifest sphere and cylinder measured by Topcon Auto-Keratorefractometer
24 months

Collaborators and Investigators

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

Sponsor

Assiut University

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

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 (Actual)

June 15, 2019

Primary Completion (Actual)

June 15, 2025

Study Completion (Actual)

June 15, 2025

Study Registration Dates

First Submitted

March 15, 2026

First Submitted That Met QC Criteria

March 15, 2026

First Posted (Actual)

March 18, 2026

Study Record Updates

Last Update Posted (Actual)

March 18, 2026

Last Update Submitted That Met QC Criteria

March 15, 2026

Last Verified

March 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • FSVPRKMA

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

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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