title: Red Reflex-Guided Big-Bubble Deep Anterior Lamellar Keratoplasty: A Simple Technique to Judge Dissection Depth.
abstract: OBJECTIVE
  To report the results of a modified big-bubble deep anterior lamellar keratoplasty technique using the intraoperative red reflex to visualize the amount of residual stroma beneath the inserted cannula.
  
  
  METHODS
  A total of 132 consecutive keratoconic eyes were included in this retrospective, noncomparative, interventional case series. Before starting surgery, pharmacologic mydriasis was induced in all eyes undergoing a big-bubble deep anterior lamellar keratoplasty procedure. After partial trephination of the recipient cornea, a spatula was inserted at the base of the incision and advanced into depth using as a reference the thin dark line seen in the red reflex ahead of the advancing tip; the stromal depth reached was measured using anterior segment optical coherence tomography. Finally, the spatula was exchanged for a 27-gauge cannula, and air was injected to create a big bubble. The stromal depth reached with the spatula, success rate of big-bubble formation, and complications were recorded.
  
  
  RESULTS
  The big bubble was obtained in 118 of 132 eyes (89.4%). Of the remaining 14 eyes, 11 underwent completion of the procedure by manual dissection and 3 were converted to penetrating keratoplasty because the bubble burst while trying to enlarge it. Perforation did not occur in any case during cannula insertion. The average thickness reached with the stromal dissection was 64.3 ± 19.5 μm.
  
  
  CONCLUSIONS
  The thin dark line, seen in the red reflex obtained with pharmacologic dilation, provides a useful and effective reference that can be used to visualize and judge the depth of dissection, thus allowing a safer and reproducible approach to the pre-Descemetic stroma.
authors.affiliation: *Department of Ophthalmology, University of Magna Graecia, Catanzaro, Italy; †Department of Ophthalmology, Ospedale Privato Villa Igea, Forlì, Italy; and ‡Istituto Internazionale per la Ricerca e Formazione in Oftalmologia (IiRFO), Forlì, Italy.
authors.forename: Vincenzo
authors.initials: V
authors.lastname: Scorcia
authors.forename: Andrea
authors.initials: A
authors.lastname: Lucisano
authors.forename: Rocco
authors.initials: R
authors.lastname: Pietropaolo
authors.forename: Vincenzo
authors.initials: V
authors.lastname: Savoca Corona
authors.forename: Giovanni
authors.initials: G
authors.lastname: Scorcia
authors.forename: Massimo
authors.initials: M
authors.lastname: Busin
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D002452:Cell Count; D003319:Corneal Stroma / Q000473:pathology*; D016039:Corneal Transplantation / Q000379:methods*; D004210:Dissection / Q000379:methods*; D004728:Endothelium, Corneal / Q000473:pathology; D005260:Female; D006801:Humans; D007640:Keratoconus / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D012025:Reflex, Pupillary; D012189:Retrospective Studies; D025321:Surgery, Computer-Assisted; D041623:Tomography, Optical Coherence; D055815:Young Adult