title: Removal and Repositioning of Intracorneal Ring Segments: Improving Corneal Topography and Clinical Outcomes in Keratoconus and Ectasia.
abstract: OBJECTIVE
  To evaluate the efficacy of removal and relocation of intracorneal ring segments for improving outcomes in treatment of keratoconus and corneal ectasia.
  
  
  METHODS
  This is a retrospective case series conducted at a cornea and refractive surgery subspecialty practice setting. Patients with previous insertion of 2 intracorneal ring segments underwent surgical removal and repositioning of segments because of unsatisfactory visual and topographic outcomes. The principal outcomes included uncorrected and corrected visual acuities, manifest refraction, topography-derived maximum keratometry (Kmax), inferior-superior topography power difference (I - S), and higher-order aberration profile derived from wavefront analysis.
  
  
  RESULTS
  Three patients are presented in this case series. Uncorrected visual acuity improved in all eyes by an average of 2.75 lines. Corrected visual acuity improved in 2 eyes and remained unchanged in 1 eye. Refractive astigmatism decreased in all patients by an average of 2.50 D. Kmax decreased by an average of 1.43 D. All patients had improvement in the I - S value with a mean decrease of 5.13 D.
  
  
  CONCLUSIONS
  Topography-guided repositioning and/or replacement of corneal ring segments can result in improved topographic, optical, and visual outcomes in patients in whom the initial result is suboptimal. In these cases, a single segment repositioned beneath the cone resulted in an improved outcome. Analysis of corneal topography can guide the surgeon in treatment planning and can suggest patients in whom such an effort will be rewarded with better results.
authors.affiliation: CLEI Center for Keratoconus, Cornea and Laser Eye Institute-Hersh Vision Group, Teaneck, and the Department of Ophthalmology, Rutgers New Jersey Medical School, Newark, NJ.
authors.forename: Kahei
authors.initials: K
authors.lastname: Chan
authors.forename: Peter S
authors.initials: PS
authors.lastname: Hersh
mesh_terms: D000328:Adult; D003319:Corneal Stroma / Q000601:surgery*; D019781:Corneal Topography; D020878:Device Removal; D004108:Dilatation, Pathologic / Q000503:physiopathology / Q000601:surgery; D005260:Female; D006801:Humans; D007640:Keratoconus / Q000503:physiopathology / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D019904:Polymethyl Methacrylate; D019736:Prostheses and Implants; D019919:Prosthesis Implantation / Q000379:methods; D012029:Refraction, Ocular / Q000502:physiology; D012086:Reoperation; D012189:Retrospective Studies; D014792:Visual Acuity / Q000502:physiology
chemical_list: D019904:Polymethyl Methacrylate