title: Intrastromal Corneal Ring Segment Explantation in Patients With Keratoconus: Causes, Technique, and Outcomes.
abstract: OBJECTIVE
  To assess the causes for intrastromal corneal ring segment (Intacs; Addition Technology Inc., Lombard, IL) explantation in patients with keratoconus, and technique for explantation, long-term outcomes, and secondary procedures to correct visual acuity.
  
  
  METHODS
  Ten eyes of 8 patients with a history of Intacs explantation between 2004 and 2012 were included in a retrospective study performed at the Bascom Palmer Eye Institute, Miami, Florida. Causes of Intacs removal, surgical technique, preoperative and postoperative corneal examination, and uncorrected and corrected distance visual acuity were documented. Additionally, corneal topography (Tomey, Nagoya, Japan) parameters such as average keratometry and corneal cylinder were assessed.
  
  
  RESULTS
  Although the segments were well positioned, the most common cause of Intacs removal was worsening visual acuity (80%). There was no statistically significant difference between pre-Intacs placement, post-Intacs placement, and post-Intacs removal in uncorrected and corrected distance visual acuity, average keratometry, or corneal cylinder, except between 1-year post-Intacs placement corrected distance visual acuity (0.57 logMAR [20/75 Snellen]) and 1-month post-Intacs removal corrected distance visual acuity (0.25 logMAR [20/36 Snellen], P =.03). Four patients underwent penetrating keratoplasty after Intacs removal with good visual outcomes.
  
  
  CONCLUSIONS
  This study demonstrates the visual and structural outcomes that returned to near baseline after Intacs explantation in keratoconic eyes.
authors.forename: Priyanka
authors.initials: P
authors.lastname: Chhadva
authors.forename: Nilufer
authors.initials: N
authors.lastname: Yesilirmak
authors.forename: Florence
authors.initials: F
authors.lastname: Cabot
authors.forename: Sonia H
authors.initials: SH
authors.lastname: Yoo
mesh_terms: D000328:Adult; D003319:Corneal Stroma / Q000601:surgery*; D019781:Corneal Topography; D020878:Device Removal / Q000379:methods*; D005260:Female; D006801:Humans; D007640:Keratoconus / Q000503:physiopathology / Q000601:surgery*; D015948:Keratoplasty, Penetrating; D008297:Male; D008875:Middle Aged; D019736:Prostheses and Implants; D012029:Refraction, Ocular / Q000502:physiology; D012189:Retrospective Studies; D014786:Vision Disorders / Q000209:etiology / Q000503:physiopathology / Q000601:surgery*; D014792:Visual Acuity / Q000502:physiology*