title: EX-PRESS® Implant Position and Function: Comparative Evaluation with Ultrasound Biomicroscopy and Optical Coherence Tomography.
abstract: OBJECTIVE
  This study evaluated the feasibility of anterior segment optical coherence tomography (OCT) and ultrasound biomicroscopy (UBM) for the imaging of EX-PRESS(®) implant.
  
  
  METHODS
  This nonrandomized comparative case series was performed at the Department of Ophthalmology of the University Hospital of Heraklion, Crete, Greece. The Ellex Eye Cubed (40 MHz) UBM and the Zeiss Visante OCT systems were used. The filtering bleb morphology (BL), aqueous outflow (AS), and tube position (TB) were evaluated by two independent observers using a quality scale of 1 (worst) to 4 (best). Data were also collected on corneal and iris clearance from the tip of the tube (CC and IC, respectively). Data from both the devices were statistically analyzed. P < 0.05 was considered as statistically significant.
  
  
  RESULTS
  Ten eyes of 10 patients (6 males) with EX-PRESS(®) implant were examined. TB, AS, and BL scores using UBM were 2.40 ± 0.39, 3.45 ± 0.72, and 2.45 ± 0.64, respectively. TB, AS, and BL scores for OCT were 3.35 ± 0.41, 1.55 ± 0.43, and 2.55 ± 0.55, respectively. AS was significantly higher with UBM whereas the opposite was true for TB. Differences in BL between OCT and UBM were not statistically significant (P > 0.05).
  
  
  CONCLUSIONS
  Imaging of the EX-PRESS(®) implant is feasible with both UBM and OCT. Both modalities allow visualization of the position of the implant tube in relation to the iris or cornea and delineate the internal structure of the filtering bleb.
authors.affiliation: Department of Ophthalmology, University Hospital of Heraklion, Heraklion, Greece; Department of Refractive Surgery, Institute of Vision and Optics, Crete, Greece.
authors.forename: Efstathios T
authors.initials: ET
authors.lastname: Detorakis
authors.affiliation: Department of Refractive Surgery, Institute of Vision and Optics, Crete, Greece.
authors.forename: Nela
authors.initials: N
authors.lastname: Stojanovic
authors.affiliation: Department of Ophthalmology, University Hospital of Heraklion, Heraklion, Greece.
authors.forename: Aikaterini
authors.initials: A
authors.lastname: Chalkia
authors.affiliation: Department of Ophthalmology, University Hospital of Heraklion, Heraklion, Greece; Department of Refractive Surgery, Institute of Vision and Optics, Crete, Greece.
authors.forename: Ioannis G
authors.initials: IG
authors.lastname: Pallikaris
mesh_terms: D000368:Aged; D000869:Anterior Eye Segment / Q000033:anatomy & histology* / Q000000981:diagnostic imaging; D001082:Aqueous Humor / Q000502:physiology; D005260:Female; D020327:Glaucoma Drainage Implants; D005902:Glaucoma, Open-Angle / Q000503:physiopathology / Q000601:surgery*; D006801:Humans; D007429:Intraocular Pressure / Q000502:physiology; D008297:Male; D033401:Microscopy, Acoustic; D008875:Middle Aged; D019919:Prosthesis Implantation; D041623:Tomography, Optical Coherence / Q000379:methods; D014065:Tonometry, Ocular
keywords: Anterior Chamber; Cornea; EX-PRESS®; Iris; Optical Coherence Tomography; Ultrasound Biomicroscopy