title: Reduced best spectacle-corrected visual acuity from inserting a thicker Intacs above and thinner Intacs below in keratoconus.
abstract: OBJECTIVE
  To report a case of decreased best spectacle-corrected visual acuity (BSCVA) 2 months after Intacs implantation.
  
  
  METHODS
  A 33-year-old woman with keratoconus and contact lens intolerance underwent Intacs surgery in the left eye at another institution. Two segments were used--a thinner one (0.25 mm) below the cone and a thicker one (0.35 mm) above the cone.
  
  
  RESULTS
  Two months postoperatively, the patient presented to our practice with BSCVA reduced from 20/20 to 20/30. The superior Intacs segment was explanted, the inferior segment was exchanged for a thicker one (0.35 mm), and collagen cross-linking with riboflavin treatment was performed. This resulted in visual, topographic, and refractive improvement with BSCVA returning to 20/20.
  
  
  CONCLUSIONS
  Single inferior segment Intacs may be more appropriate for paracentral and peripheral cones. Collagen cross-linking may help cause further flattening. Using asymmetrical segments, with the thicker segment above the cone, may increase distortions and result in loss of BSCVA.
authors.affiliation: Boxer Wachler Vision Institute, Beverly Hills, Calif, USA.
authors.forename: Colin C K
authors.initials: CC
authors.lastname: Chan
authors.forename: Brian S Boxer
authors.initials: BS
authors.lastname: Wachler
mesh_terms: D000328:Adult; D003315:Cornea / Q000601:surgery; D019781:Corneal Topography; D005139:Eyeglasses; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007640:Keratoconus / Q000503:physiopathology / Q000601:surgery*; D011182:Postoperative Care / Q000379:methods; D019736:Prostheses and Implants; D011474:Prosthesis Design; D019919:Prosthesis Implantation; D012029:Refraction, Ocular; D014792:Visual Acuity