Topography Versus Non-Topography-Guided PRK With CXL in Keratoconus

Study Overview
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Brief Summary
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To our knowledge, this study is one of the first to compare the visual results of non-topography-guided and topography-guided photorefractive keratectomy (PRK) applying sequential and simultaneous corneal cross-linking (CXL) treatment for keratoconus. Considering recent advances in cross-linking and imaging in keratoconus, the outcomes of this study can lead us to several non-invasive algorithm management options.

Detailed Description
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Interventional and comparative prospective study: Sixty-nine eyes (38 patients) suffering from keratoconus (stages 1-2 Amsler-Krumeich classification) were divided into four groups. The four groups underwent topography- and non-topography-guided PRK with sequential and simultaneous CXL. The main outcome measures were pre- and postoperative uncorrected distance visual acuity (UDVA), best corrected distance visual acuity (CDVA), manifest refraction, contrast sensitivity, and keratometry.

Official Title
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Topography Versus Non-Topography-Guided Photorefractive Keratectomy With Corneal Cross-Linking Variations in Keratoconus

Conditions
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Keratoconus

Intervention / Treatment
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* Procedure: Photorefractive keratectomy in mile keratoconus


Participation Criteria
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Eligibility Criteria
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Inclusion criteria age 34 (range from 34 to 41) stable corneal topography and refraction for at least six months estimated residual bed thickness of >410 µm Exclusion presence of macular or retinal disease, dry eye history of recurrent corneal erosions anterior segment abnormalities unstable refractive error post-surgically residual stromal bed thickness of under 350 mm autoimmune disease collagen vascular disease immunosuppressive therapy or current use of systemic corticosteroids diabetes mellitus pregnancy lactation

Ages Eligible for Study
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Minimum Age: 34 Years
Maximum Age: 41 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Intervention Model: Sequential Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Photorefractive keratectomy in mile keratoconus<br>Photorefractive keratectomy in mile keratoconus type of corneal surface ablation in for correct refractive error | Procedure: Photorefractive keratectomy in mile keratoconus<br>* Topo-guided photorefractive keratectomy will be performed using an excimer laser (Allegretto Wave Topolyzer, Alcon, Inc.) with a 6 mm optical area and a transition area of 2 mm in all eyes. At that point, the partial topography-guided photorefractive keratectomy laser treatment will be finished. The arrangement will be to treat 70% of the cylindrical and spherical part to not surpass 50μm of stromal expulsion. The estimation of 50μm as the most extreme removal depth recommended by Kanellopoulos in Athens protocol will be chosen<br>* Other names: Advance surface abelation in mild keratoconus;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| visual acuity | Visual acuity (VA) commonly refers to the clarity of vision | 3 months |