title: Intrastromal corneal ring: 12-month sighted myopic eyes.
abstract: BACKGROUND
  To evaluate the efficacy, predictability, and stability of the refractive effect produced by the Intrastromal Corneal Ring (ICR), the authors completed a 12-month study on 10 myopic eyes.
  
  
  METHODS
  Ten patients with preoperative refractive errors ranging from -2.63 diopters (D) to -4.25 D (mean, -3.30 D) participated in the study. The attempted correction was -2.50 D for a 7.0-mm diameter, 0.3-mm thick ICR. One eye of each patient received an ICR.
  
  
  RESULTS
  The average change in spherical equivalent at 12 months was -2.25 D (SD 0.54 D; range, -1.62 to -3.25 D). All patients maintained a spectacle-corrected visual acuity of 20/20 or better during the 12-month study period, with the exception of patient no. 6 who saw 20/30 at the 6-month examination. Her spectacle-corrected visual acuity returned to 20/20 a few days after the ICR was explanted and remained stable throughout the study. Uncorrected visual acuity had improved to 20/40 or better in all patients on postoperative day 1 and remained in this range for the 9 eyes (90%) during the 12 months of follow up. At postoperative month 12, 9 of 9 eyes (100%) had an uncorrected visual acuity of 20/40 or better with 3 of 9 eyes (33%) seeing 20/20 or better. The remaining patient, no. 6, experienced a tear in Descemet's membrane during the procedure and required explantation of the ring after 6 months due to induced astigmatism and deterioration of uncorrected visual acuity. Two patients developed infiltrates that resolved with the use of antibiotics. The most common postoperative ocular findings were peripheral corneal haze in all eyes that diminished over time, minute lamellar channel deposits (7 of 10 eyes, 70%), deep stromal neovascularization (5 of 10 eyes, 50%), and pannus (5 of 10 eyes, 50%).
  
  
  CONCLUSIONS
  This preliminary study shows that implantation of an intrastromal corneal ring of this dimension (0.3-mm thick) can reduce approximately 1.50 to 3.00 D of myopia and maintain spectacle-corrected visual acuity.
authors.affiliation: Department of Ophthalmology, Paulista School of Medicine, São Paulo Hospital, Brazil.
authors.forename: W
authors.initials: W
authors.lastname: Nosé
authors.forename: R A
authors.initials: RA
authors.lastname: Neves
authors.forename: T E
authors.initials: TE
authors.lastname: Burris
authors.forename: D J
authors.initials: DJ
authors.lastname: Schanzlin
authors.forename: R
authors.initials: R
authors.lastname: Belfort Júnior
mesh_terms: D000328:Adult; D003315:Cornea / Q000473:pathology; D003319:Corneal Stroma / Q000601:surgery*; D004867:Equipment Design; D005069:Evaluation Studies as Topic; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007431:Intraoperative Complications; D008297:Male; D009216:Myopia / Q000503:physiopathology / Q000601:surgery*; D011183:Postoperative Complications; D011184:Postoperative Period; D019736:Prostheses and Implants; D014792:Visual Acuity