Clinical and Structural Outcome of Conventional Versus Accelerated Corneal Collagen Cross-linking (CXL).

Study Overview
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Brief Summary
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Compare different corneal parameters and visual outcome of corneal collagen cross-linking (CXL) with conventional versus accelerated ultraviolet-A irradiation using riboflavin with hydroxypropyl methylcellulose.

Detailed Description
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40 patients with signs of progressive keratoconus are randomized to either corneal collagen cross-linking (CXL) with conventional ultraviolet-A (UVA) irradiation at 3 milliwatt/cm² (mW/ cm²) or accelerated ultraviolet-A (UVA) irradiation at 9 mW/ cm². In both groups riboflavin with hydroxypropyl methylcellulose was used. The objectives of this study are to evaluate and compare different corneal parameters (maximum corneal curvature, depth of collagen cross-linking, endothelial cell density) and clinical outcomes of uncorrected visual acuity (UCVA) and best spectacle corrected visual acuity (BSCVA)) after CXL with conventional and accelerated UVA irradiation.

Official Title
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A Randomized Study of Clinical and Structural Outcome of Corneal Collagen Crosslinking (CXL) With Conventional Versus Accelerated Ultraviolet-A Irradiation Using Riboflavin With Hydroxypropyl Methylcellulose (HPMC).

Conditions
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Keratoconus, Corneal Ectasia

Intervention / Treatment
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* Device: UV-X 1000 (3 mW/cm²)
* Procedure: UV-X 2000 (9 mW/cm²)
* Drug: riboflavin with hydroxypropyl methylcellulose


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Patients with increase of minimum of 1,0 diopter in maximum keratometry. Patients with increase in corneal astigmatism of minimum 1,0 diopter. Patients with in spherical equivalent of min 0,5 diopter. Patients living in Eastern Norway. Exclusion Criteria: Minimum pachymetric corneal thickness (Pentacam)<360 µm. Central corneal scar. Chemical burn, serious corneal infections and ocular surface diseases. Pregnancy. Lactation.

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 30 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: Treatment group A<br>Corneal collagen cross-linking using riboflavin with hydroxypropyl methylcellulose solution and ultraviolet-A (UVA) irradiation at 3 milliwatt/cm² (mW/cm²) for 30 minutes. Device: UV-X 1000 irradiator (3 mW/cm²) Drug: riboflavin with hydroxypropyl methylcellulose | Device: UV-X 1000 (3 mW/cm²)<br>* Ultraviolet-A (UVA) irradiation for 30 minutes at 3 milliwatt/cm² (mW/cm²).<br>* Other names: conventional ultraviolet-A(UVA) irradiation;Drug: riboflavin with hydroxypropyl methylcellulose<br>* Drops of riboflavin with hydroxypropyl methylcellulose will be applied in the eye for 20 minutes before ultraviolet-A(UVA) irradiation and every 2 minutes during UVA irradiation<br>* Other names: riboflavin with HPMC;|
| Active Comparator: Treatment group B<br>Corneal collagen cross-linking using riboflavin with hydroxypropyl methylcellulose solution and ultraviolet-A (UVA) irradiation at 9 mW/cm² for 10 minutes. Device: UV-X 2000 irradiator (9 mW/cm²) Drug: riboflavin with hydroxypropyl methylcellulose | Procedure: UV-X 2000 (9 mW/cm²)<br>* Ultraviolet-A (UVA) irradiation for 10 minutes at 9 mW/cm².<br>* Other names: accelerated ultraviolet-A(UVA) irradiation;Drug: riboflavin with hydroxypropyl methylcellulose<br>* Drops of riboflavin with hydroxypropyl methylcellulose will be applied in the eye for 20 minutes before ultraviolet-A(UVA) irradiation and every 2 minutes during UVA irradiation<br>* Other names: riboflavin with HPMC;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Compare change in maximum corneal curvature, visual acuity, endothelial cell density and depth of cross-linking in CXL with conventional versus accelerated UVA irradiation. | Compare change in maximum corneal curvature (Kmax; diopter), uncorrected visual acuity (UCVA, logMAR), best spectacle corrected visual acuity (BSCVA, logMAR) from baseline and depth in micrometer(µm) of corneal collagen cross-linking on anterior segment optical coherence tomography and confocal microscopy in corneal collagen cross-linking with conventional at 3 milliwatt/cm² (mW/cm²) versus accelerated (9 mW/cm²) ultraviolet-A irradiation using riboflavin with hydroxypropyl methylcellulose. | 2 years | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Compare depth of corneal collagen cross-linking on anterior segment optical coherence tomography and confocal microscopy with change in endothelial cell density in CXL with conventional versus accelerated ultraviolet-A irradiation. | Compare depth (µm) of corneal collagen cross-linking on anterior segment optical coherence tomography and confocal microscopy with change in endothelial cell density (ECD; cells/mm²) from baseline in CXL with conventional (3 mW/cm²) versus accelerated (9 mW/cm²) ultraviolet-A irradiation using riboflavin with hydroxypropyl methylcellulose.. | 2 years | 
| Compare depth of corneal collagen cross-linking on anterior segment optical coherence tomography and confocal microscopy with change in maximal corneal curvature (Kmax) and visual acuity in CXL with conventional versus accelerated UVA irradiation. | Compare depth (µm) of corneal collagen crosslinking on anterior segment optical coherence tomography and confocal microscopy with change in maximal corneal curvature (Kmax; diopter), uncorrected visual acuity (UCVA, logMAR) and best spectacle corrected visual acuity (BSCVA, logMAR) from baseline in CXL with conventional (3 mW/cm²) versus accelerated (9 mW/cm²) ultraviolet-A irradiation using riboflavin with hydroxypropyl methylcellulose. | 2 years |