title: [Intacsintracorneal ring segments in keratoconus].
abstract: BACKGROUND
  The spectrum of stage-related therapy of keratoconus has been broadened through surgical implantation of intracorneal ring segments (INTACS) as a possible method of reducing irregular astigmatism, leading to a reduction of corneal grafts especially in young, working-aged patients with keratoconus. The purpose of the present study was to evaluate the preoperative and postoperative results of femtosecond laser-assisted implantation of INTACS in ectatic corneal diseases.
  
  
  METHODS
  From August 2011 to January 2013, 20 eyes from 16 patients with a clear cornea in the visual axis suffering from hard contact lens intolerance underwent surgery in the Homburg/Saar Keratoconus Center (HKC) by the same surgeon (MEH). Among these were 16 keratoconus eyes, 1 eye with pellucid marginal degeneration und 3 eyes with post-LASIK iatrogenic keratectasia. The insertion of the INTACS ring segments was achieved by a femtosecond laser-assisted procedure that created a precise 360° tunnel at a depth of 80% of the corneal thickness (395.8 ± 38.5 μm) in the 6–7 mm zone.Results. At 6 months follow-up mean uncorrected distance visual acuity improved from 0.07 ± 0.07 preoperatively to 0.6 ± 0.26 postoperatively. Mean best-corrected distance visual acuity changed from 0.4 ± 0.15 preoperatively to 0.9 ± 0.29 postoperatively. Mean sphere decreased from −7.6 ± 6.1 dpt to −1.4 ± 2.8 dpt. Astigmatism decreased from −6.0 ± 2.8 dpt preoperatively to −4.3 ± 2.0 dpt postoperatively. There was also a reduction in the mean flat K from 47.8 ± 4.7 dpt preoperatively to 44.2 ± 5.0 dpt postoperatively and in mean steep K from 51.9 ± 5.0 dpt to 48.4 ± 6.6 dpt. The central eccentricity index in the Pentacam was reduced to around 50%. Neither intraoperative nor postoperative complications (including non-responders) were observed.
  
  
  CONCLUSIONS
  The femtosecond laser-assisted INTACS implantation provides a valid alternative to early keratoplasty for keratoconus patients with a clear central cornea and contact lens intolerance. It is a minimally invasive and reliable method for stage-related surgical management of keratoconus.
authors.affiliation: Klinik für Augenheilkunde, Universitätsklinikum des Saarlandes, UKS, Homburg/Saar. melhusseiny@hotmail.com
authors.forename: M
authors.initials: M
authors.lastname: El-Husseiny
authors.forename: T
authors.initials: T
authors.lastname: Tsintarakis
authors.forename: T
authors.initials: T
authors.lastname: Eppig
authors.forename: A
authors.initials: A
authors.lastname: Langenbucher
authors.forename: B
authors.initials: B
authors.lastname: Seitz
mesh_terms: D000328:Adult; D019544:Equipment Failure Analysis; D005260:Female; D006801:Humans; D007640:Keratoconus / Q000150:complications / Q000175:diagnosis* / Q000601:surgery*; D053685:Laser Therapy / Q000379:methods*; D008297:Male; D019736:Prostheses and Implants; D011474:Prosthesis Design; D019919:Prosthesis Implantation / Q000379:methods*; D012030:Refractive Errors / Q000175:diagnosis* / Q000209:etiology / Q000517:prevention & control*; D016896:Treatment Outcome; D014792:Visual Acuity