title: Bleb analysis by using anterior segment optical coherence tomography in two different methods of trabeculectomy.
abstract: OBJECTIVE
  To investigate the correlation between bleb morphology and IOP control via the modified Indiana Bleb Appearance Grading Scale (IBAGS) and anterior-segment optical coherence tomography (AS-OCT) in two different trabeculectomy (TLE) groups.
  
  
  METHODS
  This study involved 94 eyes with primary open angle glaucoma that underwent two different TLE methods: limbal-based TLE (group I, 62 eyes) and fornix-based TLE (group II, 32). IOP control was defined as successful with an IOP ≤ 20 mm Hg and ≥20% reduction of preoperative IOP. IBAGS and various parameters of the bleb height, extent, wall thickness, ciliochoroidal detachment (CCD), and lake under the scleral flap (LUSF) were obtained by slit-lamp and AS-OCT, respectively. Correlation between IOP control and IBAGS/AS-OCT parameters were assessed by SAS.
  
  
  RESULTS
  Both groups had the same success rate. As to correlation between IOP control and IBAGS, extent and Seidel were the best-paired parameters in group I (Cp = 3.0402, R = 0.6401), yet no parameter was significant in group II (maximum R = 0.1599). As to correlation between IOP control and AS-OCT, the combinations of height, extent, and the minimum value of bleb wall thickness were significant (Cp = 0.2037, 0.2314, R = 0.4336, 0.4330) in group I. In group II, no parameter was significant, except CCD and/or LUSF (P = 0.032). As to coincidence of IBAGS and AS-OCT parameters, height and extent in group I (P = 0.000, P = 0.000) and height in group II were statistically significant (P = 0.020).
  
  
  CONCLUSIONS
  IOP control in limbal-based TLE seemed to be more dependent on the large size and thinned-wall bleb than that in fornix-based TLE.
authors.affiliation: Department of Ophthalmology, Japanese Red Cross Medical Center, Tokyo, Japan.
authors.forename: Teruhiko
authors.initials: T
authors.lastname: Hamanaka
authors.forename: Takayasu
authors.initials: T
authors.lastname: Omata
authors.forename: Shinichiro
authors.initials: S
authors.lastname: Sekimoto
authors.forename: Takakazu
authors.initials: T
authors.lastname: Sugiyama
authors.forename: Yasunori
authors.initials: Y
authors.lastname: Fujikoshi
mesh_terms: D000328:Adult; D000869:Anterior Eye Segment / Q000473:pathology*; D003228:Conjunctiva / Q000473:pathology*; D003430:Cross-Sectional Studies; D005260:Female; D005500:Follow-Up Studies; D005902:Glaucoma, Open-Angle / Q000473:pathology / Q000503:physiopathology / Q000601:surgery*; D006801:Humans; D007429:Intraocular Pressure; D012189:Retrospective Studies; D041623:Tomography, Optical Coherence / Q000379:methods*; D014130:Trabeculectomy / Q000379:methods*
keywords: AS-OCT; IBAGS; bleb morphology; fornical-based TLE; limbal-based TLE