title: High-definition imaging of trabeculectomy blebs using spectral domain optical coherence tomography adapted for the anterior segment.
abstract: BACKGROUND
  The aim of this work was to image trabeculectomy blebs using spectral domain optical coherence tomography (SDOCT).
  
  
  METHODS
  In this prospective cross-sectional study, patients who had undergone trabeculectomy with at least 3 months of follow up were included. Blebs were imaged using an adapted SDOCT system (Cirrus HD-OCT, Carl Zeiss Meditec Inc., Dublin, CA, USA) and time domain anterior segment optical coherence tomography (ASOCT) (Visante OCT, Carl Zeiss Meditec Inc.). An observer masked to clinical data assessed the utility of SDOCT and ASOCT in visualizing structures in successful and failed blebs.
  
  
  RESULTS
  Fifty-one eyes were imaged, of which 43 (84.3%) were successful. SDOCT showed wall thickening (93.0% vs. 67.4%, P = 0.006) and discrete hyporeflective spaces in the wall (88.4% vs. 14.0%, P < 0.0001) in a greater proportion of successful blebs than ASOCT. SDOCT showed the bleb cavity (23.3% vs. 48.8%, P = 0.02), scleral flap (34.9% vs. 90.7%, P < 0.0001), subflap space (20.9% vs. 72.1%, P < 0.0001) and ostium (9.3% vs. 88.4%, P < 0.0001) in fewer successful blebs than ASOCT. The internal ostium was not visualized in any failed bleb using SDOCT, whereas ASOCT showed the ostium in 87.5% of failed blebs (P = 0.001). SDOCT showed cystic spaces in the bleb wall in a greater proportion of successful blebs than failed blebs (88.4% vs. 37.5%, P = 0.005).
  
  
  CONCLUSIONS
  SDOCT imaging was able to show fine superficial features in the bleb wall. However, SDOCT had limited clinical utility in that it did not provide useful information about deep features such as flap position, bleb cavity formation or patency of the subflap space and internal ostium.
authors: Department of Ophthalmology, National University of Health System, Singapore 119074, Singapore.
authors: Mandeep
authors: M
authors: Singh
authors: Jovina L S
authors: JL
authors: See
authors: Maria C
authors: MC
authors: Aquino
authors: Lennard S Y
authors: LS
authors: Thean
authors: Paul T K
authors: PT
authors: Chew
mesh_terms: D000368:Aged; D000869:Anterior Eye Segment / Q000473:pathology*; D001768:Blister / Q000473:pathology*; D003131:Combined Modality Therapy; D003430:Cross-Sectional Studies; D005260:Female; D005901:Glaucoma / Q000188:drug therapy / Q000601:surgery*; D006801:Humans; D008297:Male; D016685:Mitomycin / Q000008:administration & dosage; D011446:Prospective Studies; D041623:Tomography, Optical Coherence; D014130:Trabeculectomy
chemical_list: D016685:Mitomycin