title: Microbubble incision as a new rescue technique for big-bubble deep anterior lamellar keratoplasty with failed bubble formation.
abstract: OBJECTIVE
  To describe a new surgical technique allowing dissection down to Descemet membrane in big-bubble deep anterior lamellar keratoplasty (DALK) with failed big-bubble formation (the "microbubble incision technique").
  
  
  METHODS
  This is an interventional case series of 10 consecutive patients with keratoconus undergoing intended big-bubble DALK with failure to establish a normal big bubble. In all patients, repeated air injections into the stroma were performed, leaving a whitish colored stroma. Lamellar dissection as far down as possible was then performed within this white tissue. As soon as the anterior chamber was visible, a large remaining intrastromal air bubble was incised with a sharp 15-degree knife introduced perpendicular to the tissue to open up this predescemetic bubble. If deeper air bubbles were still visible, this approach was repeated. Using a blunt spatula, this new layer was then prepared and viscodissection performed.
  
  
  RESULTS
  Using this novel approach, in 9 of the 10 patients, it was possible to dissect down to Descemet membrane. Macroperforation made conversion to penetrating keratoplasty necessary in 1 patient. Microperforations not necessitating conversion occurred in 2 patients. All 9 patients with "rescued" DALK had an uneventful postoperative course and had a mean visual acuity of 20/63 ± 20/125 (range, 20/500-20/50) and a mean endothelial cell count of 1672 ± 163 cells per square millimeter (range, 1493-1867 cells/mm) at 3 months.
  
  
  CONCLUSIONS
  Microbubble incision is a new rescue technique for big-bubble DALK patients without bubble formation allowing for a safer dissection down to Descemet membrane.
authors.affiliation: Department of Ophthalmology, University of Erlangen-Nürnberg, Erlangen, Germany.
authors.forename: Stephan
authors.initials: S
authors.lastname: Riss
authors.forename: Ludwig M
authors.initials: LM
authors.lastname: Heindl
authors.forename: Björn O
authors.initials: BO
authors.lastname: Bachmann
authors.forename: Friedrich E
authors.initials: FE
authors.lastname: Kruse
authors.forename: Claus
authors.initials: C
authors.lastname: Cursiefen
mesh_terms: D000328:Adult; D000388:Air; D002452:Cell Count; D003319:Corneal Stroma / Q000601:surgery*; D003886:Descemet Membrane / Q000601:surgery*; D057111:Descemet Stripping Endothelial Keratoplasty / Q000379:methods*; D004210:Dissection / Q000379:methods; D058450:Endotamponade / Q000379:methods; D004728:Endothelium, Corneal / Q000473:pathology; D005260:Female; D006801:Humans; D007498:Iris / Q000601:surgery; D007640:Keratoconus / Q000601:surgery*; D053844:Lasers, Solid-State / Q000627:therapeutic use; D008297:Male; D008875:Middle Aged; D014792:Visual Acuity / Q000502:physiology; D055815:Young Adult