PRoTECT: Corneal Wavefront Guided PRK + Epi-off CXL vs. PTK+Epi-off CXL in Keratoconus
For patients and families
In plain language
An automatic summary of structured registry data. It is an orientation aid, not a substitute for the official protocol or a physician assessment.
- What is being studied
- The protocol lists: Schwind AMARIS excimer laser, Corneal collagen crosslinking epi-off accelerated.
- Who it may be relevant to
- Registry conditions: Keratoconus. Basic parameters: from 18 years · All.
- What needs checking
- Age, condition and sex are only basic indicators. Prior treatment, laboratory values and other mandatory requirements appear in the eligibility criteria below.
- Where it takes place
- Mexico
- Next step
- Save the trial, show it to the treating physician, and confirm current recruitment with the study center. Costs, documents and travel →
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Official title
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
Overview
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.
Interventions
- 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 \[equivalent to 3 minutes "on" time\].
Primary outcome measures
- Change in best-corrected distance visual acuity (logMAR) [Time frame: Baseline to 12 months]
Secondary outcome measures (10)
- Change in Kmax (Diopters) [Time frame: Baseline; 3; 6; 12 months]
- Change in corneal higher-order aberrations (µm RMS) [Time frame: Baseline; 3,6,12 months]
- Change in manifest refraction spherical equivalent (Diopters) [Time frame: Baseline; 3;6;12 months]
- Corneal haze (Scheimpflug densitometry units) [Time frame: Baseline; 3;6;12 months]
- Corvis ST metric: Ambrosio Relational Thickness horizontal (ART-h) [Time frame: Baseline; 3,6; 12 months]
- Visual Functioning Questionnaire (NEI VFQ-25) [Time frame: Baseline; 6;12 months]
- Endothelial cell density (cells/mm²; specular microscopy) [Time frame: Baseline; 1; 3; 6; 12 months]
- Serious corneal adverse events [Time frame: Baseline to 12 months]
- Corneal haze (Fantes grade) [Time frame: Baseline; 3; 6; 12 months]
- Corvis ST metric: Inverse Concavity Radius [Time frame: Baseline; 3; 6; 12 months]
Eligibility criteria
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
Criteria are shown verbatim from the registry (in English). Final eligibility is always assessed by the study center.
Healthy volunteers: No
Study design
- Allocation
- Randomized
- Model
- Parallel assignment
- Masking
- Double blind
- Primary purpose
- Treatment
Study locations
Mexico · 1 center
- Instituto de Oftalmología FAP Conde de Valenciana, IAP Sede Centro — Mexico City
Identifiers
NCT: NCT07372911 · PRoTECT-CXL-TGPRK-MX