title: Influence of intrastromal corneal ring segment implantation on corneal biomechanical parameters in keratoconic eyes.
abstract: OBJECTIVE
  To assess the influence of intrastromal corneal ring segment (ICRS) implantation on corneal biomechanics in patients with keratoconus.
  
  
  METHODS
  Patients with keratoconus who underwent femtosecond laser-assisted ICRS (Keraring) implantation were evaluated with the ocular response analyzer (ORA). Metrics of corneal biomechanical parameters, including corneal hysteresis (CH) and corneal resistance factor (CRF) were measured both before and after surgery. The postoperative measurements recorded at the 1st, 3rd and 6th months, and 1st and 2nd years after surgery were analyzed.
  
  
  RESULTS
  The mean CRF was significantly lower in the early postoperative period (1st and 3rd month); however, the difference between the mean preoperative and late postoperative (6th months, 1st and 2nd years) CRF values was not significant. There were no significant differences between the mean preoperative and postoperative CH values.
  
  
  CONCLUSIONS
  In the early postoperative period a significant temporary decrease in CRF was observed after the femtosecond laser-assisted ICRS implantation; however, this surgery did not alter the CH significantly in the same time interval. Both CH and CRF did not show significant alteration from preoperative values in the late postoperative period.
authors.affiliation: Department of Ophthalmology, Faculty of Medicine, Yeditepe University, Sakir Kesebir Cad. Gazi Umur Pasa Sokak No: 28, Balmumcu Besiktas, 34349, Istanbul, Turkey. ebrugorgun@gmail.com.
authors.forename: Ebru
authors.initials: E
authors.lastname: Gorgun
authors.affiliation: Department of Ophthalmology, Faculty of Medicine, Yeditepe University, Sakir Kesebir Cad. Gazi Umur Pasa Sokak No: 28, Balmumcu Besiktas, 34349, Istanbul, Turkey.
authors.forename: Raciha Beril
authors.initials: RB
authors.lastname: Kucumen
authors.affiliation: Department of Ophthalmology, Faculty of Medicine, Yeditepe University, Sakir Kesebir Cad. Gazi Umur Pasa Sokak No: 28, Balmumcu Besiktas, 34349, Istanbul, Turkey.
authors.forename: Nursal Melda
authors.initials: NM
authors.lastname: Yenerel
mesh_terms: D000328:Adult; D001696:Biomechanical Phenomena / Q000502:physiology*; D003315:Cornea / Q000000981:diagnostic imaging / Q000502:physiology*; D003319:Corneal Stroma / Q000601:surgery*; D005260:Female; D006801:Humans; D007429:Intraocular Pressure / Q000502:physiology; D007640:Keratoconus / Q000503:physiopathology / Q000601:surgery*; D053685:Laser Therapy; D008297:Male; D011446:Prospective Studies; D019736:Prostheses and Implants; D019919:Prosthesis Implantation; D014065:Tonometry, Ocular; D014463:Ultrasonography; D014792:Visual Acuity / Q000502:physiology