title: Effect of treatment sequence in combined intrastromal corneal rings and corneal collagen crosslinking for keratoconus.
abstract: OBJECTIVE
  To compare 2 sequences of combined intrastromal corneal ring segment (ICRS) implantation and ultraviolet/riboflavin-mediated corneal collagen crosslinking (CXL) in progressive keratoconus.
  
  
  METHODS
  Dunya Eye Hospital, Istanbul, Turkey.
  
  
  METHODS
  In this prospective comparative randomized consecutive study, CXL was followed by ICRS implantation (Group 1) or ICRS implantation was followed by CXL (Group 2). Uncorrected (UDVA) and corrected (CDVA) distance visual acuities, spherical equivalent (SE), manifest cylinder (cylinder), and mean keratometry (K) were compared preoperatively and postoperatively.
  
  
  RESULTS
  The mean interval between treatments was 7 months +/- 2 (SD) (mean follow-up, 13 +/- 1 months). The mean UDVA and CDVA improved in both groups (UDVA: 0.07 +/- 0.09 to 0.25 +/- 0.12, Group 1, and 0.11 +/- 0.09 to 0.32 +/- 0.21, Group 2; CDVA: 0.24 +/- 0.11 to 0.41 +/- 0.20 and 0.22 +/- 0.16 to 0.55 +/- 0.2, respectively). The mean SE, cylinder, and mean K values decreased in both groups (SE: -7.13 +/- 3.34 D to -2.98 +/- 2.33 D, Group 1, and -7.05 +/- 5.54 D to -2.81 +/- 4.08 D, Group 2; cylinder: -4.38 +/- 2.03 D to -2.62 +/- 1.93 D and -4.68 +/- 2.60 D to -2.20 +/- 1.67 D, respectively; mean K: 52.47 +/- 4.01 D to 48.31 +/- 3.65 D and 52.06 +/- 4.93 D to 48.08 +/- 4.13 D, respectively). Overall, there was more improvement in CDVA, SE, and mean K in Group 2 than in Group 1.
  
  
  CONCLUSIONS
  Implantation of ICRS followed by CXL resulted in greater improvement of keratoconus.
authors.affiliation: Dunya Eye Hospital, Istanbul, Turkey.
authors.forename: Efekan
authors.initials: E
authors.lastname: Coskunseven
authors.forename: Mirko R
authors.initials: MR
authors.lastname: Jankov
authors.forename: Farhad
authors.initials: F
authors.lastname: Hafezi
authors.forename: Serife
authors.initials: S
authors.lastname: Atun
authors.forename: Ebru
authors.initials: E
authors.lastname: Arslan
authors.forename: George D
authors.initials: GD
authors.lastname: Kymionis
mesh_terms: D000293:Adolescent; D000328:Adult; D003094:Collagen / Q000378:metabolism*; D003131:Combined Modality Therapy; D003319:Corneal Stroma / Q000378:metabolism* / Q000528:radiation effects / Q000601:surgery*; D005260:Female; D006801:Humans; D007640:Keratoconus / Q000188:drug therapy / Q000601:surgery / Q000628:therapy*; D008297:Male; D017319:Photosensitizing Agents / Q000627:therapeutic use*; D011446:Prospective Studies; D019736:Prostheses and Implants; D019919:Prosthesis Implantation; D012256:Riboflavin / Q000627:therapeutic use; D016896:Treatment Outcome; D014466:Ultraviolet Rays; D014792:Visual Acuity; D055815:Young Adult
chemical_list: D017319:Photosensitizing Agents; D003094:Collagen; D012256:Riboflavin