title: Sequential topical riboflavin with or without ultraviolet a radiation with delayed intracorneal ring segment insertion for keratoconus.
abstract: OBJECTIVE
  To report refractive, topographic, pachymetric, tonometric, and corneal biomechanical outcomes 24 months after corneal cross-linking (CXL), followed by insertion of intrastromal corneal ring segments (ICRS) in keratoconic eyes.
  
  
  METHODS
  Prospective randomized clinical trial.
  
  
  METHODS
  
  
  
  METHODS
  Institutional.
  
  
  METHODS
  Thirty-nine eyes of 31 patients, allocated into 2 groups.
  
  
  METHODS
  Patients in the CXL group underwent corneal CXL with riboflavin and ultraviolet A (UVA) light. Patients in the riboflavin eyedrops group received riboflavin 0.1% (w/v) eyedrops - 20% dextran solution for 1 month. After 3 months, all patients underwent insertion of ICRS.
  
  
  METHODS
  Uncorrected visual acuity (UCVA), best spectacle-corrected visual acuity (BSCVA), and topography were evaluated at baseline, at 1 month and 3 months after CXL or riboflavin eyedrops, and again at 1-, 3-, 6-, 12-, and 24-month intervals after ICRS insertion.
  
  
  RESULTS
  Mean (standard deviation [SD]) baseline UCVA and BSCVA in the CXL group and the riboflavin eyedrops group were 1.12 (0.59) and 0.84 (0.49), and 0.68 (0.43) and 0.45 (0.23), respectively; 24-month mean (SD) UCVA and BSCVA in the CXL group and the riboflavin eyedrops group were 0.79 (0.50) and 0.62 (0.28), and 0.52 (0.45) and 0.32 (0.21), respectively, with no statistically significant difference between groups (P = .70 and P = .78).There were no statistical differences between groups postoperatively at 24 months for all 3 topographic parameters, flattest-K1 (P = .81), steepest-K2 (P = .68), and average keratometry (mean power; P = .52).
  
  
  CONCLUSIONS
  ICRS insertion, with or without prior CXL, showed no difference between groups in terms of refractive, topographic, pachymetric, tonometric, and corneal biomechanical results at 24 months.
authors.affiliation: Vision Institute, Department of Ophthalmology, Federal University of São Paulo, Brazil. adimararenesto@uol.com.br
authors.forename: Adimara da Candelaria
authors.initials: Ada C
authors.lastname: Renesto
authors.forename: Luiz Alberto S
authors.initials: LA
authors.lastname: Melo
authors.forename: Marta de Filippi
authors.initials: Mde F
authors.lastname: Sartori
authors.forename: Mauro
authors.initials: M
authors.lastname: Campos
mesh_terms: D000293:Adolescent; D000328:Adult; D001696:Biomechanical Phenomena; D002452:Cell Count; D003094:Collagen / Q000378:metabolism; D003131:Combined Modality Therapy; D003319:Corneal Stroma / Q000378:metabolism / Q000601:surgery*; D019781:Corneal Topography; D004548:Elasticity / Q000502:physiology; D004728:Endothelium, Corneal / Q000473:pathology; D005260:Female; D006801:Humans; D007429:Intraocular Pressure; D007640:Keratoconus / Q000188:drug therapy* / Q000378:metabolism / Q000503:physiopathology / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D017319:Photosensitizing Agents / Q000627:therapeutic use*; D011446:Prospective Studies; D019736:Prostheses and Implants; D019919:Prosthesis Implantation; D012029:Refraction, Ocular / Q000502:physiology; D012256:Riboflavin / Q000627:therapeutic use*; D041623:Tomography, Optical Coherence; D016896:Treatment Outcome; D014466:Ultraviolet Rays; D014792:Visual Acuity / Q000502:physiology; D055815:Young Adult
chemical_list: D017319:Photosensitizing Agents; D003094:Collagen; D012256:Riboflavin