title: Persistent Epithelial Defects and Corneal Opacity After Collagen Cross-Linking With Substitution of Dextran (T-500) With Dextran Sulfate in Compounded Topical Riboflavin.
abstract: OBJECTIVE
  Collagen cross-linking (CXL) is a commonly performed procedure to prevent the progression of keratoconus. Riboflavin is an essential part of the procedure, which facilitates both the cross-linking process and protection of intraocular structures. Dextran can be added to riboflavin to create an isotonic solution. This case report highlights the importance of compounding riboflavin with the correct dextran solution.
  
  
  METHODS
  A retrospective case series.
  
  
  RESULTS
  Six eyes of 4 male patients with keratoconus aged from 20 to 38 years underwent CXL with substitution of 20% dextran (T-500) with 20% dextran sulfate in a compounded riboflavin 0.1% solution. Postoperatively, persistent corneal epithelial defects, stromal haze, and then scarring occurred. Corneal transplantation was performed for visual rehabilitation but was complicated by graft rejection followed by failure (n = 1 eye), dehiscence (n = 4), cataract (n = 2), post-laser ablation haze (n = 1), and steroid-induced glaucoma (n = 2). The visual outcome was <6/18 in all 6 cases because of irregular astigmatism and stromal haze. Thinning, vascularization, and scarring of the residual host tissue were noted.
  
  
  CONCLUSIONS
  Substitution of dextran (T-500) with dextran sulfate in riboflavin solutions during CXL results in loss of vision from permanent corneal opacity. Residual host changes may compromise the results of corneal transplantation.
authors.affiliation: *Sydney Eye Hospital, Save Sight Institute, University of Sydney, Brisbane, Australia; †University of the Witwatersrand, Johannesburg, South Africa; and ‡Terrace Eye Centre, University of Queensland.
authors.forename: Roland
authors.initials: R
authors.lastname: Höllhumer
authors.forename: Stephanie
authors.initials: S
authors.lastname: Watson
authors.forename: Peter
authors.initials: P
authors.lastname: Beckingsale
mesh_terms: D000328:Adult; D003094:Collagen / Q000378:metabolism; D003318:Corneal Opacity / Q000139:chemically induced* / Q000175:diagnosis / Q000601:surgery; D003319:Corneal Stroma / Q000378:metabolism; D003432:Cross-Linking Reagents; D016264:Dextran Sulfate / Q000009:adverse effects*; D003911:Dextrans / Q000627:therapeutic use*; D004339:Drug Compounding; D057915:Drug Substitution; D019573:Epithelium, Corneal / Q000187:drug effects* / Q000473:pathology; D006801:Humans; D007640:Keratoconus / Q000188:drug therapy* / Q000378:metabolism; D015948:Keratoplasty, Penetrating; D008297:Male; D017319:Photosensitizing Agents / Q000627:therapeutic use; D012189:Retrospective Studies; D012256:Riboflavin / Q000627:therapeutic use*; D014466:Ultraviolet Rays; D014792:Visual Acuity / Q000187:drug effects; D055815:Young Adult
chemical_list: D003432:Cross-Linking Reagents; D003911:Dextrans; D017319:Photosensitizing Agents; D003094:Collagen; D016264:Dextran Sulfate; D012256:Riboflavin