title: Bilateral ring-shaped intrastromal opacities after corneal cross-linking for keratoconus.
abstract: OBJECTIVE
  To report a case of bilateral, ring-shaped, intrastromal corneal opacities after corneal cross-linking (CXL) for progressive keratoconus.
  
  
  METHODS
  A 21-year-old man with bilateral, progressive keratoconus underwent CXL with riboflavin 0.1% and ultraviolet A (UVA) light in the right eye and, 6 months later, in the left eye.
  
  
  RESULTS
  One day after CXL, the right eye showed a sharply demarcated white ring in the corneal periphery. The ring involved the superficial stroma at 2 mm from the limbus, extended from 1 to 11 o'clock, and was 1.5-mm wide. Corneal topography showed marked central flattening. Six months after treatment, a residual, faint, ring-shaped opacity remained, with a decrease in corneal ectasia. Cross-linking was then performed in the left eye. Different ultraviolet devices were used in the two eyes. On postoperative day 1, the left eye also showed a white ring of stromal opacity. Scheimpflug imaging showed corneal stromal contraction in the zone of whitening. At final examination, >1 year after surgery, corrected visual acuity was 0.00 logMAR with cylinder of 2.00 diopters in both eyes.
  
  
  CONCLUSIONS
  The bilateral intrastromal corneal changes were innocuous in the long-term, with preservation of good visual acuity and successful stabilization of progressive keratoconus.
authors.affiliation: Department of Ophthalmology, Istituto Clnico Humanitas, Rozzano, Milan, Italy. fabrizio@camesasca.com
authors.forename: Fabrizio I
authors.initials: FI
authors.lastname: Camesasca
authors.forename: Paolo
authors.initials: P
authors.lastname: Vinciguerra
authors.forename: Theo
authors.initials: T
authors.lastname: Seiler
mesh_terms: D003094:Collagen / Q000378:metabolism; D003318:Corneal Opacity / Q000175:diagnosis / Q000209:etiology* / Q000503:physiopathology; D003319:Corneal Stroma / Q000378:metabolism / Q000473:pathology*; D019781:Corneal Topography; D003432:Cross-Linking Reagents / Q000627:therapeutic use*; D006801:Humans; D007640:Keratoconus / Q000188:drug therapy* / Q000378:metabolism; D008297:Male; D017319:Photosensitizing Agents / Q000627:therapeutic use*; D011183:Postoperative Complications; D012256:Riboflavin / Q000627:therapeutic use; D014466:Ultraviolet Rays; D014792:Visual Acuity / Q000502:physiology; D055815:Young Adult
chemical_list: D003432:Cross-Linking Reagents; D017319:Photosensitizing Agents; D003094:Collagen; D012256:Riboflavin