title: Factors affecting visual acuity after accelerated crosslinking in patients with progressive keratoconus.
abstract: OBJECTIVE
  The present study aimed to report the outcomes of patients with progressive keratoconus who were treated via accelerated crosslinking (CXL) 6 months earlier and to determine the factors that promoted improved visual acuity after treatment.
  
  
  METHODS
  This retrospective study included 35 eyes of 34 patients with progressive keratoconus who underwent CXL. Topographical measurements were obtained preoperatively and in the first, third, and sixth months postoperatively using a rotating Scheimpflug camera. The uncorrected visual acuity (UCVA), best-corrected visual acuity (BCVA), flat keratometry (K) value (K1), steep K value (K2), average K value (avgK), topographic cylindrical value (Cyl), apical keratoscopy front (AKf), apical keratoscopy back (AKb), symmetry index front (SIf), symmetry index back (SIb), and thinnest point of the cornea (ThkMin) were recorded.
  
  
  RESULTS
  At the 6-month follow-up, the mean UCVA and BCVA values were improved, and the K values remained stable. Statistically significant decreases in AKf (p=0.04) and the thinnest point of the cornea (p=0.001) and a statistically significant increase in AKb (p=0.01) were observed. A correlation analysis revealed that the preoperative BCVA, UCVA, K1, K2, avgK, AKf, and AKb values significantly affected visual acuity at the 6-month follow-up.
  
  
  CONCLUSIONS
  Accelerated CXL is an effective treatment for the prevention or even reversal of keratoconus progression. The preoperative K values and apexes of the anterior and posterior cornea were found to affect visual acuity at 6 months after accelerated CXL. Both AKb steepening and AKf flattening appear to be important factors in the stabilization of keratometric values and improvement of visual outcomes.
authors.affiliation: Department of Opthalmology, Bagcilar Training and Research Hospital, Istanbul, Turkey.
authors.forename: Ahmet
authors.initials: A
authors.lastname: Kırgız
authors.affiliation: Department of Opthalmology, Bagcilar Training and Research Hospital, Istanbul, Turkey.
authors.forename: Kürşat
authors.initials: K
authors.lastname: Atalay
authors.affiliation: Department of Opthalmology, Bagcilar Training and Research Hospital, Istanbul, Turkey.
authors.forename: Kübra Şerefoğlu
authors.initials: KŞ
authors.lastname: Çabuk
authors.affiliation: Department of Opthalmology, Bagcilar Training and Research Hospital, Istanbul, Turkey.
authors.forename: Havva
authors.initials: H
authors.lastname: Kaldırım
authors.affiliation: Beyoglu Eye Training and Research Hospital, Istanbul, Turkey.
authors.forename: Muhittin
authors.initials: M
authors.lastname: Taşkapılı
mesh_terms: D000293:Adolescent; D000328:Adult; D003094:Collagen / Q000494:pharmacology / Q000627:therapeutic use*; D019781:Corneal Topography; D003432:Cross-Linking Reagents / Q000494:pharmacology / Q000627:therapeutic use*; D018450:Disease Progression; D005260:Female; D006801:Humans; D007640:Keratoconus / Q000188:drug therapy*; D008297:Male; D017319:Photosensitizing Agents / Q000494:pharmacology / Q000627:therapeutic use; D011184:Postoperative Period; D057234:Preoperative Period; D012016:Reference Values; D015203:Reproducibility of Results; D012189:Retrospective Studies; D012256:Riboflavin / Q000494:pharmacology / Q000627:therapeutic use; D013997:Time Factors; D016896:Treatment Outcome; D014466:Ultraviolet Rays; D014792:Visual Acuity / Q000187:drug effects*; D055815:Young Adult
chemical_list: D003432:Cross-Linking Reagents; D017319:Photosensitizing Agents; D003094:Collagen; D012256:Riboflavin