title: Intrastromal corneal ring segments and posterior chamber phakic intraocular lens implantation for keratoconus correction.
abstract: OBJECTIVE
  To evaluate the efficacy, safety, and predictability of sequential implantation of Keraring intrastromal corneal ring segments (ICRS) and an Implantable Collamer Lens phakic intraocular lens (pIOL) with corneal relaxing incisions for refractive correction of keratoconus.
  
  
  METHODS
  Fernández-Vega Ophthalmological Institute, Oviedo, Spain.
  
  
  METHODS
  Cohort study.
  
  
  METHODS
  This study comprised patients with keratoconus who had ICRS implantation followed 6 months later by pIOL implantation with corneal relaxing incisions. The uncorrected (UDVA) and corrected (CDVA) distance visual acuities and residual refractive errors, analyzed using vector analysis, were recorded preoperatively, 6 months after ICRS implantation, and 6 months after pIOL implantation.
  
  
  RESULTS
  The study enrolled 40 eyes (31 patients). The mean UDVA (decimal) was 0.11 Snellen ± 0.05 (SD) preoperatively, 0.18 ± 0.14 Snellen 6 months after ICRS implantation (P=.001), and 0.50 ± 0.27 Snellen 6 months after pIOL implantation (P<.0001). The mean CDVA was 0.56 ± 0.23 Snellen, 0.68 ± 0.25 Snellen, and 0.73 ± 0.20 Snellen, respectively (all P<.0001). Six months after pIOL implantation, the efficacy index was 0.88 and the safety index, 1.28. At 6 months, 65% of eyes were within ±1.00 diopter (D) of the desired refraction and 45% were within ±0.50 D. The mean spherical equivalent after pIOL implantation was -1.19 ± 1.33 D.
  
  
  CONCLUSIONS
  Sequential ICRS and pIOL implantation plus corneal relaxing incisions provided good visual and refractive outcomes, indicating that it is a predictable procedure for refractive correction of keratoconus.
  
  
  BACKGROUND
  No author has a financial or proprietary interest in any material or method mentioned.
authors.affiliation: Fernández-Vega Ophthalmological Institute, Surgery Department, School of Medicine, University of Oviedo, Oviedo, Spain. j.alfonso@fernandez-vega.com
authors.forename: José F
authors.initials: JF
authors.lastname: Alfonso
authors.forename: Carlos
authors.initials: C
authors.lastname: Lisa
authors.forename: Luis
authors.initials: L
authors.lastname: Fernández-Vega
authors.forename: David
authors.initials: D
authors.lastname: Madrid-Costa
authors.forename: Arancha
authors.initials: A
authors.lastname: Poo-López
authors.forename: Robert
authors.initials: R
authors.lastname: Montés-Micó
mesh_terms: D000328:Adult; D015331:Cohort Studies; D003319:Corneal Stroma / Q000601:surgery*; D005260:Female; D006801:Humans; D007640:Keratoconus / Q000503:physiopathology / Q000601:surgery*; D019654:Lens Implantation, Intraocular; D008297:Male; D008875:Middle Aged; D054120:Phakic Intraocular Lenses; D019904:Polymethyl Methacrylate; D011379:Prognosis; D011446:Prospective Studies; D019736:Prostheses and Implants; D019919:Prosthesis Implantation; D012029:Refraction, Ocular / Q000502:physiology; D014792:Visual Acuity / Q000502:physiology
chemical_list: D019904:Polymethyl Methacrylate