title: Evaluation of the tightness of contact between  limbal sclera tunnel and tube following Ahmed  glaucoma valve implantation.
abstract: OBJECTIVE
  To investigate whether the tightness of contact between the tube and the limbal sclera tunnel can be evaluated with high-magnification anterior segment optical coherence tomography (OCT) imaging following Ahmed glaucoma valve implantation.
  
  
  METHODS
  Tightness between the tube and the limbal sclera tunnel was investigated with the CAM-L cornea lens adapter of the Optovue Fourier-domain OCT (RTVue-OCT) for 21 uncomplicated Ahmed glaucoma valves implanted in 20 eyes of 19 patients with glaucoma. Nineteen valves were implanted 4 to 124 months earlier (late postoperative cases) and 2 valves 1 day prior to the imaging (early postoperative cases). All valves were introduced into the anterior chamber via a limbal sclera tunnel.
  
  
  RESULTS
  The limbal intratunnel part of the tube was successfully imaged in all but 2 cases where an additional full-thickness sclera patch was used. In 14 cases, the contact was tight without tube compression. In  5 cases, the tube was partially compressed but remained open in the limbal sclera tunnel, and redilated behind the limbus. No case with loose contact or peritubular filtration was seen. The posterior run of the tube was successfully imaged in all 19 cases without a full-thickness sclera patch.
  
  
  CONCLUSIONS
  High-magnification imaging with the CAM- L anterior segment adapter of the RTVue-OCT allows detailed examination of the limbal insertion area of tubes in both the early and late postoperative periods. Therefore this method may potentially be applied for detection of complications related to tube insertion after glaucoma drainage device surgery.
authors.affiliation: Department of Ophthalmology, Semmelweis University, Budapest - Hungary. hgbudapest@gmail.com
authors.forename: Gábor
authors.initials: G
authors.lastname: Holló
authors.forename: Farzaneh
authors.initials: F
authors.lastname: Naghizadeh
mesh_terms: D000328:Adult; D000368:Aged; D000867:Anterior Chamber / Q000473:pathology*; D005260:Female; D005901:Glaucoma / Q000503:physiopathology / Q000601:surgery*; D020327:Glaucoma Drainage Implants; D006801:Humans; D007429:Intraocular Pressure / Q000502:physiology; D016850:Limbus Corneae; D008297:Male; D008875:Middle Aged; D019919:Prosthesis Implantation; D060489:Prosthesis Retention; D012590:Sclera / Q000601:surgery*; D013524:Surgical Flaps; D013536:Suture Techniques; D041623:Tomography, Optical Coherence; D055815:Young Adult