An interventional study of Schwind AMARIS excimer laser and Corneal collagen crosslinking epi-off accelerated in Keratoconus, sponsored by Instituto de Oftalmología Fundación Conde de Valenciana. Recruiting at 1 site in Mexico. Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2026-01-28.
Sponsored by Instituto de Oftalmología Fundación Conde de Valenciana · Not applicable, Interventional, and Treatment
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.
313 studies on the registry are indexed under Keratoconus; 56 are open to participants now.
This study's planned enrollment of 50 is above the median of 40 across 205 interventional studies indexed under Keratoconus.
Browse Keratoconus studies →Instituto de Oftalmología Fundación Conde de Valenciana is the lead sponsor of 45 studies on the registry; 10 are open to participants now.
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Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
Exclusion Criteria:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
A condition in which the immune system attacks the body’s own tissues, such as rheumatoid arthritis, lupus, psoriasis, type 1 diabetes or inflammatory bowel disease.
Immunotherapy studies often leave out active autoimmune disease, and some name exceptions, such as thyroid disease on replacement hormone. Check the exceptions this study lists.
Informed consent
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Autoimmune disease
A condition in which the immune system attacks the body’s own tissues, such as rheumatoid arthritis, lupus, psoriasis, type 1 diabetes or inflammatory bowel disease.
Immunotherapy studies often leave out active autoimmune disease, and some name exceptions, such as thyroid disease on replacement hormone. Check the exceptions this study lists.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Corneal wavefront guided therapeutic PRK (50 µm) with Schwind AMARIS, followed by accelerated epi-off CXL. 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 \[equivalent to 3 minutes "on" time\].
Device: Schwind AMARIS excimer laser · Procedure: Corneal collagen crosslinking epi-off accelerated
Epithelial removal by PTK using Schwind AMARIS, followed by accelerated epi-off CXL. 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 \[equivalent to 3 minutes "on" time\].
Device: Schwind AMARIS excimer laser · Procedure: Corneal collagen crosslinking epi-off accelerated
Used for corneal wavefront guided PRK therapeutic ablation (50 µm) or for PTK epithelial removal, according to arm assignment.
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 \[equivalent to 3 minutes "on" time\].
Change in best-corrected distance visual acuity (logMAR)
ETDRS-based CDVA in logMAR; change from baseline at 12 months; primary analysis by ANCOVA adjusted for baseline; one study eye per participant.
Time frame: Baseline to 12 months
Change in Kmax (Diopters)
Pentacam Scheimpflug tomography; maximum keratometry (D); change from baseline at each time point.
Time frame: Baseline; 3; 6; 12 months
Change in corneal higher-order aberrations (µm RMS)
Wavefront/aberrometry total HOAs RMS (µm) over 6-mm pupil; change from baseline.
Time frame: Baseline; 3,6,12 months
Change in manifest refraction spherical equivalent (Diopters)
Manifest refraction SE (D); change from baseline.
Time frame: Baseline; 3;6;12 months
Corneal haze (Scheimpflug densitometry units)
CCT and corneal haze as measured by Pentacam Corneal Densitometry. Unit of measure: gray units.
Time frame: Baseline; 3;6;12 months
Corvis ST metric: Ambrosio Relational Thickness horizontal (ART-h)
ART-h as measured by Corvis ST. Unit of measure: microns
Time frame: Baseline; 3,6; 12 months
Visual Functioning Questionnaire (NEI VFQ-25)
NEI VFQ-25 composite and subscale scores computed per scoring manual; change from baseline. 0 to 100, where higher scores indicate better vision-related quality of life.
Time frame: Baseline; 6;12 months
Endothelial cell density (cells/mm²; specular microscopy)
Non-contact specular microscopy; primary metric = endothelial cell density (cells/mm²); secondary metrics (if collected) = coefficient of variation and hexagonality; change from baseline; one study eye per participant.
Time frame: Baseline; 1; 3; 6; 12 months
Serious corneal adverse events
Incidence of protocol-defined serious ocular AEs ( infectious keratitis, perforation, persistent epithelial defect \>14 days, ≥20% endothelial cell density loss, visually significant stromal scarring requiring surgery).
Time frame: Baseline to 12 months
Corneal haze (Fantes grade)
Fantes clinical haze grade (ordinal); recorded at each visit. Units: Fantes grade. Scale: 0-4 scale, higher scores = worse haze.
Time frame: Baseline; 3; 6; 12 months
Corvis ST metric: Inverse Concavity Radius
Inverse Concavity Radius as measured by Corvis ST. Unit of measure: mm
Time frame: Baseline; 3; 6; 12 months
Plan to share: Undecided
No publications or documents are linked to this record.
Started Sep 2025 (actual). Primary completion is estimated for Sep 2026, 12 months after the start.
Of 59 non-industry interventional studies with no phase under Keratoconus, half reached primary completion within 34 months of starting (the median), counting those still running; a quarter within 12 and three quarters within 54. This study's planned 12 months is below that.
Counting every sponsor, half of 68 studies reached it within 34 months; a quarter within 12 and three quarters within 59.
How these figures are worked out, and which studies are left out of them.
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Instituto de Oftalmología Fundación Conde de Valenciana