title: VHF digital ultrasound three-dimensional scanning in the diagnosis of myopic regression after corneal refractive surgery.
abstract: OBJECTIVE
  To perform VHF digital ultrasound scanning and analysis of a case of high-myopic undercorrection in an eye that had undergone multiple surgical interventions for the correction of an initial refraction of -12.00 diopters (D).
  
  
  METHODS
  A 49-year-old woman was evaluated after undergoing three surgical interventions for correction of an initial refraction of -12.00 D in the left eye. Automated lamellar keratoplasty (ALK) was followed by arcuate keratotomy (for induced astigmatism) and surface photorefractive keratectomy (PRK). The residual ametropia on presentation was -6.75 -3.50 x 95 degrees. VHF digital ultrasound scanning and analysis was performed.
  
  
  RESULTS
  On ultrasound, the ALK interface was clearly visible. Residual stromal thickness beneath the cap was at least 275 microm. The absence of Bowman's layer indicated the region of PRK. New stroma and nascent stromal layers were differentiated within the flap. Neo stromal deposition and central epithelial hyperplasia were determined to be responsible for the myopic shift, as opposed to biomechanical changes.
  
  
  CONCLUSIONS
  In this case, refraction, slit-lamp examination, and topography were unable to provide a diagnosis for regression following multiple corneal refractive procedures. By providing layered anatomical mapping, VHF digital ultrasound scanning was able to exclude a diagnosis of ectasia and provide anatomical diagnostic information to explain the clinical observations.
authors.affiliation: Service du Prof. Laurent Laroche, Centre Hospitalier National d'Ophtalmologie des Quinze-Vingts, Paris, France. dzr@londonvisionclinic.com
authors.forename: Dan Z
authors.initials: DZ
authors.lastname: Reinstein
authors.forename: Barbara
authors.initials: B
authors.lastname: Ameline
authors.forename: Michel
authors.initials: M
authors.lastname: Puech
authors.forename: Guy
authors.initials: G
authors.lastname: Montefiore
authors.forename: Laurent
authors.initials: L
authors.lastname: Laroche
mesh_terms: D001251:Astigmatism / Q000000981:diagnostic imaging / Q000209:etiology / Q000601:surgery; D003315:Cornea / Q000000981:diagnostic imaging*; D019781:Corneal Topography; D016039:Corneal Transplantation; D005260:Female; D006801:Humans; D021621:Imaging, Three-Dimensional; D054018:Lasers, Excimer; D008875:Middle Aged; D009216:Myopia / Q000000981:diagnostic imaging* / Q000209:etiology / Q000601:surgery; D018903:Photorefractive Keratectomy; D012086:Reoperation; D014463:Ultrasonography