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

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).

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.

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.

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.