RECRUITINGINTERVENTIONAL

PRoTECT: Corneal Wavefront Guided PRK + Epi-off CXL vs. PTK+Epi-off CXL in Keratoconus

Corneal Wavefront Guided PRK Combined With Epi-off Corneal Cross-Linking Versus Epi-off Corneal Cross-Linking With PTK Epithelial Removal in Keratoconus: A Randomized Clinical Trial

About This Trial

Keratoconus causes irregular astigmatism and reduced vision. Epi-off corneal crosslinking (CXL) stabilizes the cornea but often leaves higher-order aberrations uncorrected. This randomized, parallel-group trial compares corneal wavefront guided photorefractive keratectomy (corneal wavefront guided PRK, 50 µm therapeutic ablation) combined with accelerated epi-off CXL versus epi-off CXL with epithelial removal by phototherapeutic keratectomy (PTK) using a Schwind AMARIS excimer laser, in adults with keratoconus. The primary endpoint is change in best-corrected distance visual acuity (logMAR) at 12 months. Key secondary endpoints include Kmax, corneal higher-order aberrations, manifest refraction, Scheimpflug densitometry (haze) and Fantes grade, Corvis ST biomechanics, NEI VFQ-25, and endothelial cell density by non-contact specular microscopy at 1, 3, 6 and 12 months.

Who May Be Eligible (Plain English)

Who May Qualify: - Age 18-40 years - Diagnosis of keratoconus, ABCD Belin stage I-III at baseline - Minimum (thinnest) corneal pachymetry ≥ 450 µm pre-op - Written willing to sign a consent form - Age-stratified progression requirements: - 18-25 y: keratoconus stage I-III (progression not mandatory) - 25-35 y: documented progression (meet ≥ 2 Table-1 criteria below) or, if recent documentation is absent, high-risk features for future progression: Kmax \> 53 D, strong family history, severe atopy with persistent eye rubbing, or any of the following over 12 months: ΔKmax ≥ 1.0 D, thinnest pachymetry decrease ≥ 10 µm, or increase in manifest cylinder ≥ 1.0 D - 35-40 y: clear, unequivocal recent progression (meet ≥ 2 Table-1 criteria); late-onset documented progression may be considered Who Should NOT Join This Trial: - Central corneal scars or opacities - Prior ocular surgery or trauma (exception: prior LASIK if it is the cause of post-surgical ectasia, per protocol text) - autoimmune conditions (where your immune system attacks your own body) or uncontrolled diabetes mellitus - Pregnancy or lactation - Contact lens wear within 2 weeks before baseline evaluation Always talk to your doctor about whether this trial is right for you.

Original Eligibility Criteria

View original clinical language

Inclusion Criteria: * Age 18-40 years * Diagnosis of keratoconus, ABCD Belin stage I-III at baseline * Minimum (thinnest) corneal pachymetry ≥ 450 µm pre-op * Written informed consent * Age-stratified progression requirements: * 18-25 y: keratoconus stage I-III (progression not mandatory) * 25-35 y: documented progression (meet ≥ 2 Table-1 criteria below) or, if recent documentation is absent, high-risk features for future progression: Kmax \> 53 D, strong family history, severe atopy with persistent eye rubbing, or any of the following over 12 months: ΔKmax ≥ 1.0 D, thinnest pachymetry decrease ≥ 10 µm, or increase in manifest cylinder ≥ 1.0 D * 35-40 y: clear, unequivocal recent progression (meet ≥ 2 Table-1 criteria); late-onset documented progression may be considered Exclusion Criteria: * Central corneal scars or opacities * Prior ocular surgery or trauma (exception: prior LASIK if it is the cause of post-surgical ectasia, per protocol text) * Autoimmune disease or uncontrolled diabetes mellitus * Pregnancy or lactation * Contact lens wear within 2 weeks before baseline evaluation

Treatments Being Tested

DEVICE

Schwind AMARIS excimer laser

Used for corneal wavefront guided PRK therapeutic ablation (50 µm) or for PTK epithelial removal, according to arm assignment.

PROCEDURE

Corneal collagen crosslinking epi-off accelerated

Riboflavin-UVA crosslinking performed after epithelial removal (corneal wavefront guided PRK arm via PRK; comparator arm via PTK). Intensity: 30 mW/cm² (pulsed 1 s on / 1 s off; 50% duty cycle). Total energy (fluence): 5.4 J/cm². Total time (elapsed): 6 minutes \[equivalent to 3 minutes "on" time\].

Locations (1)

Instituto de Oftalmología FAP Conde de Valenciana, IAP Sede Centro

Mexico City, Mexico City, Mexico