title: Predictors for treatment outcomes after corneal crosslinking for keratoconus: a validation study.
abstract: Previous research suggested that baseline corrected distance visual acuity (CDVA) and maximum keratometry (Kmax) are the predictors for effectiveness of corneal crosslinking (CXL) for keratoconus. The aim of this study was to validate the previously determined predictors in a new treatment cohort. A prospective cohort of 112 eyes in 90 consecutive patients was used to validate the results of 102 eyes in 79 patients from our previous prospective cohort. All patients were treated using epithelium-off corneal CXL in a tertiary hospital setting. Primary outcomes were changes in CDVA (LogMAR) and Kmax between baseline and 1-year post-treatment. Predictive factors for both outcomes were determined using univariable and multivariable analyses. Lower pretreatment CDVA was found to be the sole independent factor predicting an improvement in CDVA 1 year after CXL (β coefficient: -0.476, P < 0.01). Kmax flattening is more likely to take place in eyes with preoperative central cones (β coefficient: 0.655, P < 0.01). These results are consistent with our initial research and indicate high reproducibility in the new cohort. The previously postulated prediction model for postoperative CDVA showed limited predictive value in the validation cohort (R2= 0.15). The clinical implication of these results is that patients with lower pretreatment visual acuity are more likely to benefit from CXL (with respect to visual acuity), and patients with more central cones will benefit more in terms of cone flattening. Furthermore, those results can be used to guide customization of the crosslinking treatment.
authors.affiliation: Utrecht Cornea Research Group, Department of Ophthalmology, University Medical Center Utrecht, Office E03.136, PO Box 85500, 3508 GA, Utrecht, The Netherlands. d.a.godefrooij@umcutrecht.nl.
authors.forename: Daniel A
authors.initials: DA
authors.lastname: Godefrooij
authors.affiliation: Utrecht Cornea Research Group, Department of Ophthalmology, University Medical Center Utrecht, Office E03.136, PO Box 85500, 3508 GA, Utrecht, The Netherlands.
authors.forename: Kim
authors.initials: K
authors.lastname: Boom
authors.affiliation: Utrecht Cornea Research Group, Department of Ophthalmology, University Medical Center Utrecht, Office E03.136, PO Box 85500, 3508 GA, Utrecht, The Netherlands.
authors.forename: Nienke
authors.initials: N
authors.lastname: Soeters
authors.affiliation: Utrecht Cornea Research Group, Department of Ophthalmology, University Medical Center Utrecht, Office E03.136, PO Box 85500, 3508 GA, Utrecht, The Netherlands.
authors.forename: Saskia M
authors.initials: SM
authors.lastname: Imhof
authors.affiliation: Utrecht Cornea Research Group, Department of Ophthalmology, University Medical Center Utrecht, Office E03.136, PO Box 85500, 3508 GA, Utrecht, The Netherlands.
authors.forename: Robert P L
authors.initials: RP
authors.lastname: Wisse
mesh_terms: D003315:Cornea / Q000187:drug effects* / Q000473:pathology; D019781:Corneal Topography; D003432:Cross-Linking Reagents / Q000008:administration & dosage*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007640:Keratoconus / Q000175:diagnosis / Q000188:drug therapy* / Q000503:physiopathology; D008297:Male; D010778:Photochemotherapy / Q000379:methods*; D017319:Photosensitizing Agents / Q000627:therapeutic use*; D011446:Prospective Studies; D012029:Refraction, Ocular; D013997:Time Factors; D016896:Treatment Outcome; D014466:Ultraviolet Rays; D014792:Visual Acuity; D055815:Young Adult
chemical_list: D003432:Cross-Linking Reagents; D017319:Photosensitizing Agents
keywords: Crosslinking; Keratoconus; Multivariable analysis; Prognosis