title: Depth of intrastromal corneal ring segments by OCT.
abstract: OBJECTIVE
  To compare the depth of intrastromal corneal ring segments (ICRS) with the expected depth value using optical coherence tomography (OCT).
  
  
  METHODS
  This was a retrospective comparative study in an ophthalmic unit in a government hospital, the Baruch Padeh Medical Center, Poriya, Israel. Ten eyes of 8 patients with 18 ICRS were reviewed. Eleven segments were Intacs (Addition Technology, Inc.) and 7 Kerarings (Mediphacos). Using anterior segment OCT (OPKO OTI) the shortest distance from the epithelium to the segment at 3 points was measured for each segment. The 3 points are proximal, middle, and distal to the incision.
  
  
  RESULTS
  The mean depth of the 18 segments was 360±68 µm. The mean maximal and minimal depths were 383±70 and 336±72 µm, respectively. The mean depths of the distal, central, and proximal point measurements of all ICRS were 358±79, 361±77, and 362±59 µm, respectively; no significant difference was found. No part of the segments tended to be more superficial than others (p=0.98). There was no significant difference between Intacs and Kerarings depths (p=0.43). There was a significant difference between the expected ICRS depth and the OCT measurements (mean 480±20) and 360±68), respectively.
  
  
  CONCLUSIONS
  The ICRS actual depth was less than expected. There was mild variability in segment depth, both between segments and along the same segment. No significant difference was found between the depth of Intacs and Kerarings.
authors.affiliation: Ophthalmology Unit of the Baruch Padeh Medical Center, Poriya, Israel; Faculty of Medicine, Bar Ilan University, Galille, Israel. mnaftali@poria.health.gov.il
authors.forename: Modi
authors.initials: M
authors.lastname: Naftali
authors.forename: Haneen
authors.initials: H
authors.lastname: Jabaly-Habib
mesh_terms: D003319:Corneal Stroma / Q000473:pathology* / Q000601:surgery*; D006801:Humans; D007640:Keratoconus / Q000601:surgery*; D019736:Prostheses and Implants; D019919:Prosthesis Implantation; D012189:Retrospective Studies; D041623:Tomography, Optical Coherence