title: Intracorneal Ring Segments Implantation for Corneal Ectasia.
abstract: To provide an overview of the predictability, safety, and efficacy of intrastromal corneal ring segment (ICRS) implantation as a tool to improve visual acuity and its association with other techniques such as corneal collagen cross-linking (CXL), addressing biomechanical outcomes, models, surgical planning and technique, indications, contraindications, and complications in ectatic corneas.
  
  
  
  Literature review.
  
  
  
  ICRSs have been used to regularize the corneal shape and reduce corneal astigmatism and higher order aberrations, improve visual acuity to acceptable limits, and delay, or eventually prevent, a corneal keratoplasty in keratoconic eyes. Changes in ICRS thickness and size, combination of techniques, and the addition of femtosecond lasers to dissect more foreseeable channels represent an improvement toward more predictable results. Several studies have shown, over time, the long-term efficacy and safety of ICRS treatment for keratoconus, with variable predictability, maintaining the early satisfactory outcomes regarding visual acuity, keratometry, and corneal thickness. It is just as important to ensure that the disease will not progress as it is to improve the visual acuity. Therefore, many studies have shown combined techniques using ICRS implantation and CXL. Also, further limitations of ICRS implantation can be addressed when associated with phakic intraocular lens implantation and photorefractive keratectomy.
  
  
  
  ICRS implantation has shown effectiveness and safety in most cases, including combined procedures. In properly selected eyes, it can improve both refraction and vision in patients with keratoconus. [J Refract Surg. 2016;32(12):829-839.].
authors.forename: Natalia T
authors.initials: NT
authors.lastname: Giacomin
authors.forename: Glauco R
authors.initials: GR
authors.lastname: Mello
authors.forename: Carla S
authors.initials: CS
authors.lastname: Medeiros
authors.forename: Alyin
authors.initials: A
authors.lastname: Kiliç
authors.forename: Crislaine C
authors.initials: CC
authors.lastname: Serpe
authors.forename: Hirlana G
authors.initials: HG
authors.lastname: Almeida
authors.forename: Newton
authors.initials: N
authors.lastname: Kara-Junior
authors.forename: Marcony R
authors.initials: MR
authors.lastname: Santhiago
mesh_terms: D001251:Astigmatism / Q000601:surgery; D003131:Combined Modality Therapy; D063171:Corneal Pachymetry; D003319:Corneal Stroma / Q000601:surgery*; D048988:Corneal Surgery, Laser; D019781:Corneal Topography; D057108:Corneal Wavefront Aberration / Q000601:surgery; D004108:Dilatation, Pathologic / Q000601:surgery; D006801:Humans; D007431:Intraoperative Complications; D007640:Keratoconus / Q000601:surgery*; D017319:Photosensitizing Agents / Q000627:therapeutic use; D011183:Postoperative Complications; D019736:Prostheses and Implants; D019919:Prosthesis Implantation; D014792:Visual Acuity / Q000502:physiology
chemical_list: D017319:Photosensitizing Agents