Complications and Explantation Reasons in Intracorneal Ring Segments (ICRS) Implantation: A Systematic Review.

Purpose: To review the intraoperative and postoperative complications after intracorneal ring segment implantation and to report the explantation rate among the available scientific literature.

Methods: Three different databases (PubMed, Web of Science, and Scopus) were assessed from January 1995 to June 2019. The keywords used were: ring, rings, ICRS (intracorneal ring segments), segment, segments or Intacs, complication, explantation, explanted, retired, and removal.

Results: The selection process of this systematic review study is described in a flow diagram. A total of 39 studies published between 1995 and 2019 were included. Sixteen studies were case reports, 21 were case series studies, and 2 were chart analysis works. This study enrolled 1,946 participants, and 2,590 eyes were included. The postoperative complications described in most studies included migration, ring extrusion, corneal thinning, corneal melting, and some type of infective keratitis. These complications together with glare, halos, fluctuating vision, neovascularization, foreign body sensation, or pain represented most of the causes. The percentage rate of explantation ranged from 0.5% up to 83.3%. If we analyze those articles with a high number of implantations (2,124 eyes), an explantation rate between 0% and 1.4% was obtained.

Conclusions: The complication rate and explantation ratio in segments of the intracorneal ring segments analyzed in the available scientific literature are minimal. Therefore, patient selection, surgery planning, and postoperative follow-up are critical to the success of surgery. [J Refract Surg. 2019;35(11):740-747.].