title: Optical coherence tomography characteristics of different types of big bubbles seen in deep anterior lamellar keratoplasty by the big bubble technique.
abstract: PurposeTo define optical coherence tomography (OCT) characteristics of type-1, type-2, and mixed big bubbles (BB) seen in deep anterior lamellar keratoplasty.MethodsHuman sclero-corneal discs were obtained from UK (30) and Canada (16) eye banks. Air was injected into corneal stroma until a BB formed. UK samples were fixed in formalin before scanning with Fourier-domain (FD-OCT). One pair of each type of BB was scanned fresh. All BB obtained from Canada were scanned fresh with time-domain (TD-OCT). For each OCT machine used, type-1 BB from which Descemets membrane (DM) was partially peeled, were also scanned. The morphological characteristics of the scans were studied.ResultsFD-OCT of the posterior wall of type-1 (Dua's layer (DL) with DM) and type-2 BB (DM alone) both revealed a double-contour hyper-reflective curvilinear image with a hypo-reflective zone in between. The anterior line of type-2 BB was thinner than that seen with type-1 BB. In mixed BB, FD-OCT showed two separate curvilinear images. The anterior image was a single hyper-reflective line (DL), whereas the posterior image, representing the posterior wall of type-2 BB (DM) was made of two hyper-reflective lines with a dark space in between. TD-OCT images were similar with less defined component lines, but the entire extent of the BB could be visualised.ConclusionOn OCT examination the DM and DL present distinct features, which can help identify type-1, type-2, and mixed BB. These characteristics will help corneal surgeons interpret intraoperative OCT during lamellar corneal surgery.
authors.affiliation: Larry A Donoso Laboratory for Eye Research, Section of Ophthalmology, Division of Clinical Neuroscience, University of Nottingham, Nottingham, UK.
authors.forename: S L
authors.initials: SL
authors.lastname: AlTaan
authors.affiliation: University of British Columbia Vancouver, Vancouver, BC, Canada.|Department of Ophthalmology, University Hospital Brussels, Brussels, Belgium.
authors.forename: K
authors.initials: K
authors.lastname: Termote
authors.affiliation: Larry A Donoso Laboratory for Eye Research, Section of Ophthalmology, Division of Clinical Neuroscience, University of Nottingham, Nottingham, UK.
authors.forename: M S
authors.initials: MS
authors.lastname: Elalfy
authors.affiliation: Larry A Donoso Laboratory for Eye Research, Section of Ophthalmology, Division of Clinical Neuroscience, University of Nottingham, Nottingham, UK.
authors.forename: E
authors.initials: E
authors.lastname: Hogan
authors.affiliation: Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna, Austria.
authors.forename: R
authors.initials: R
authors.lastname: Werkmeister
authors.affiliation: Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna, Austria.|Department of Clinical Pharmacology, Medical University of Vienna, Austria.
authors.forename: L
authors.initials: L
authors.lastname: Schmetterer
authors.affiliation: University of British Columbia Vancouver, Vancouver, BC, Canada.
authors.forename: S
authors.initials: S
authors.lastname: Holland
authors.affiliation: Larry A Donoso Laboratory for Eye Research, Section of Ophthalmology, Division of Clinical Neuroscience, University of Nottingham, Nottingham, UK.
authors.forename: H S
authors.initials: HS
authors.lastname: Dua
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000388:Air; D003315:Cornea; D003319:Corneal Stroma / Q000000981:diagnostic imaging* / Q000601:surgery; D016039:Corneal Transplantation; D003886:Descemet Membrane / Q000000981:diagnostic imaging*; D005125:Eye Banks; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D014019:Tissue Donors; D009927:Tissue and Organ Procurement; D041623:Tomography, Optical Coherence; D014617:Vacuoles