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Are changes in visual acuity and astigmatism after corneal cross-linking (CXL) in keratoconus predictable?

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To evaluate changes in corrected distance visual acuity (CDVA), ratio of anterior and posterior corneal radii over the thinnest region of the cornea (ARC/PRC), and astigmatism after cross-linking (CXL) in keratoconus.


Subjective refraction and ARC/PRC (using Pentacam™) were monitored over 1 year in (I) keratoconus treated with routine CXL (n = 53), (II) relatively stable keratoconus (n = 23), and (III) age/gender matched controls (n = 24).


CDVA (median, mode, interquartile range) improved significantly in group I, compared with groups II and III (p < 0.05), from 0.45 (0.60, 0.20–0.63) to 0.80 (0.95, 0.60–0.95); change in CDVA was associated with preop CDVA (p < 0.01 at all times postop). ARC/PRC (mean ± sd, 95% CI) changed from 1.362 (± 0.048, 1.347–1.377) to 1.425 (± 0.073, 1.401–1.449). CDVA and ARC/PRC remained stable in II and III. Significant relationships were revealed between logCDVA and ARC/PRC in I and II (at 12 months, I rs =  − 0.464, II rs − 0.449) and logCDVA at postop(y), log CDVA at preop(x1), and ARC/PRC at preop(x2) in I (at 12 months, y = 0.356x1 − 1.312x2 + 1.806, r21 = 0.494, r22 = 0.203). Astigmatic power (mean ± sd, 95% CI) improved from − 3.10DC (± 1.52, − 3.55 to − 2.66) to − 2.53DC (± 1.24, − 2.90 to − 2.17) in I, and worsened from − 1.27DC (± 1.32, − 1.81 to − 0.73) to − 1.61DC (± 1.28, − 2.13 to − 1.09) in II. Vector analysis revealed in group I (a) the power of the surgically induced astigmatism (SIA) was linked to astigmatic power at preop and (b) the difference between the axis of astigmatism at preop(ø) and the axis of the SIA was linked to ø.


CXL improved CDVA, increased the ARC/PRC ratio, and modified the association between CDVA and ARC/PRC. The change in CDVA was linked to preop CDVA and ARC/PRC values. The association between SIA and preop astigmatism implies there is not a simple cause and effect relationship with CXL.

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Authors and Affiliations



Fanka Gilevska: conception and design, investigation, data curation, formal analysis, methodology, project administration, validation, visualization, writing the manuscript, visualization.

Alma Biscevic: conception and design, formal analysis, interpretation of data, methodology, critical revision.

Smiljka Popovic Suic: conception and design, methodology, supervision, validation.

Maja Bohac: conception and design, interpretation of data, writing the manuscript, project administration, critical revision.

Sudi Patel: conception and design, analysis and interpretation of data, critical revision.

All authors approved the version to be published and agree to be accountable for all aspects of the work in ensuring that questions related to the accuracy or integrity of any part of the work are appropriately investigated and resolved.

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Correspondence to Fanka Gilevska.

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The study was performed under the tenets of Helsinki agreement and approved by the Ethics committee at the Sistina Ophthalmology hospital.

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Gilevska, F., Biscevic, A., Popovic Suic, S. et al. Are changes in visual acuity and astigmatism after corneal cross-linking (CXL) in keratoconus predictable?. Graefes Arch Clin Exp Ophthalmol 259, 2259–2268 (2021).

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