Corneal wavefront-guided PRK plus epi-off CXL versus PTK plus epi-off CXL for keratoconus

Is this trial a fit for you?

A plain-English reading of the study's rules. Only the study team can confirm whether you qualify.

What this trial studies

This is a randomized, parallel-group trial comparing two surface-ablation approaches combined with accelerated epi-off corneal collagen cross-linking using a Schwind AMARIS excimer laser. One arm receives corneal wavefront-guided PRK (50 µm therapeutic ablation) followed by accelerated epi-off CXL, and the other arm receives epithelial removal by PTK followed by the same accelerated epi-off CXL protocol. The primary outcome is change in best-corrected distance visual acuity (logMAR) at 12 months, with key secondary outcomes including Kmax, corneal higher-order aberrations, manifest refraction, densitometry/haze, corneal biomechanics, NEI VFQ-25, and endothelial cell density measured at 1, 3, 6 and 12 months. Eligible participants are adults 18–40 years with ABCD Belin stage I–III keratoconus and minimum thinnest pachymetry ≥ 450 µm, with age-stratified progression requirements.

Why it matters

Who can join: the full rules

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

Where it's running

• Instituto de Oftalmología FAP Conde de Valenciana, IAP Sede Centro
  Mexico City, Mexico City, Mexico Recruiting

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How to take part

1. Review the eligibility criteria above with your treating physician.
2. Check the official listing on ClinicalTrials.gov for the latest contact details and recruitment status.
3. Contact the study coordinator or principal investigator to ask for pre-screening. Pre-screening is free and never obligates you to enroll.