title: Continuous corneal intrastromal ring implantation for treatment of keratoconus in an Iranian population.
abstract: OBJECTIVE
  To evaluate the effect of mechanical implantation of a continuous intrastromal ring in keratoconus.
  
  
  METHODS
  Prospective, interventional, nonrandomized, case series.
  
  
  METHODS
  The MyoRing (Dioptex GmbH) was implanted after creation of an intrastromal pocket for 95 eyes of 95 patients with moderate and advanced keratoconus. All patients had at least 12 months of follow-up. Preoperative and postoperative visual acuity, keratometry, aberrometry, and refraction were the main outcome measures of the study.
  
  
  RESULTS
  A significant improvement in uncorrected and corrected distance visual acuity was observed 1 month after surgery, which was consistent with the significant reduction in sphere (5.74 diopters [D]) and cylinder (3.02 D). No significant changes were detected in these parameters afterward. Furthermore, a significant corneal flattening of a mean value of 9.78 D was found. Both spherical myopia and astigmatism underwent reduction, but the reduction in myopia was more remarkable than astigmatism. Higher-order aberrations and coma-like aberrations decreased significantly, but spherical aberrations increased after surgery. No significant change in central corneal thickness was observed at any point after operation. There were no significant differences between 2 keratometry groups (higher or lower than 53 D) in visual gain after the procedure. There were no major complications during or after surgery. MyoRing explantation was performed in 4 eyes (4%). The refraction, visual acuity, and corneal topography returned to the preoperative status 1 month later for all 4 eyes.
  
  
  CONCLUSIONS
  MyoRing implantation has an acceptable efficacy profile in moderate and advanced keratoconus.
authors: Department of Ophthalmology, Tehran University of Medical Sciences, Farabi Eye Hospital, Tehran, Iran.
authors: Mahmoud
authors: M
authors: Jabbarvand
authors: Ahmad
authors: A
authors: Salamatrad
authors: Hesam
authors: H
authors: Hashemian
authors: Mehdi
authors: M
authors: Khodaparast
mesh_terms: D057128:Aberrometry; D000328:Adult; D003319:Corneal Stroma / Q000473:pathology / Q000601:surgery*; D019781:Corneal Topography; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D015994:Incidence; D007492:Iran / Q000453:epidemiology; D007640:Keratoconus / Q000453:epidemiology / Q000503:physiopathology / Q000601:surgery*; D053685:Laser Therapy / Q000379:methods*; D008297:Male; D011446:Prospective Studies; D019736:Prostheses and Implants; D012029:Refraction, Ocular; D016896:Treatment Outcome; D014792:Visual Acuity