title: Intrastomal corneal ring segments: reversibility of refractive effect.
abstract: OBJECTIVE
  To evaluate the reversibility of refractive effect following removal of the ICRS (intrastromal corneal ring segments; Intacs).
  
  
  METHODS
  Data from 34 eyes from which ICRS were removed during United States FDA Phase II and III clinical trials were evaluated with regard to segment size, loss or change of best spectacle-corrected visual acuity (BSCVA), any change of uncorrected visual acuity (UCVA), manifest spherical equivalent refraction, manifest cylinder refraction, stability of manifest cylinder refraction, and subjective visual symptoms.
  
  
  RESULTS
  Out of 725 initial or contralateral eyes placed with the ICRS during Phase II and III clinical trials, segments were removed from 34 eyes (4.7%). Other than one (1/725, 0.1%) safety related ICRS removal, 30/725 (4.1%) were due to visual symptoms. ICRS removal was accomplished under topical anesthesia without complications in all eyes. The mean length of time the segments remained in the cornea after initial surgery was 10.3 +/- 5.4 months. At 3 months after ICRS removal, 21 eyes had monitored data available and were within +/-1 line or 10 letters of their preoperative BSCVA. Twenty eyes (20/21, 95%) returned to within +/-1.00 D of their preoperative manifest spherical equivalent refraction. All eyes had a stable refraction at the 3-month examination after removal, and a manifest spherical equivalent refraction within +/-1.00 D of their 1-month examination after removal. Nineteen eyes (19/21, 90%) returned to within +/-2 lines and 16 eyes (16/21, 76%) returned to within +/-1 line of preoperative UCVA.
  
  
  CONCLUSIONS
  The ICRS (Intacs) was easily and safely removed, and eyes returned to preoperative refractive status within 3 months.
authors.affiliation: Department of Ophthalmology, Mount Sinai School of Medicine, New York, NY 10029-6574, USA.  pasbell@mssm.edu
authors.forename: P A
authors.initials: PA
authors.lastname: Asbell
authors.forename: O O
authors.initials: OO
authors.lastname: Uçakhan
authors.forename: R L
authors.initials: RL
authors.lastname: Abbott
authors.forename: K A
authors.initials: KA
authors.lastname: Assil
authors.forename: T E
authors.initials: TE
authors.lastname: Burris
authors.forename: D S
authors.initials: DS
authors.lastname: Durrie
authors.forename: R L
authors.initials: RL
authors.lastname: Lindstrom
authors.forename: D J
authors.initials: DJ
authors.lastname: Schanzlin
authors.forename: S M
authors.initials: SM
authors.lastname: Verity
authors.forename: G O
authors.initials: GO
authors.lastname: Waring
mesh_terms: D003319:Corneal Stroma / Q000503:physiopathology* / Q000601:surgery; D020878:Device Removal; D005260:Female; D006801:Humans; D008297:Male; D009216:Myopia / Q000503:physiopathology* / Q000601:surgery; D019904:Polymethyl Methacrylate; D011183:Postoperative Complications; D019736:Prostheses and Implants; D019919:Prosthesis Implantation; D012029:Refraction, Ocular / Q000502:physiology; D012449:Safety; D014792:Visual Acuity / Q000502:physiology*
chemical_list: D019904:Polymethyl Methacrylate