title: Bleb morphology characteristics and effect on positional intraocular pressure variation.
abstract: OBJECTIVE
  To study bleb morphology and positional intraocular pressure (IOP) change (IOP supine to IOP sitting).
  
  
  METHODS
  In this observational case series, blebs were graded for height, extent, vascularity, microcysts, and "ring of steel." Positional IOP change was analyzed using the paired t test. Associations between IOP change and bleb morphologies were evaluated by regression adjusting for inter-eye dependency.
  
  
  RESULTS
  Ninety-five eyes of 68 subjects were included. Decreased bleb height (P = .05), absence of microcysts (P = .02), and increased bleb vascularity (P = .02) were associated with larger positional IOP change. Twenty patients with a filter in one eye and a medically treated fellow eye had larger positional IOP change in the medically treated eye (6.1 vs 4.6 mm Hg, respectively; P = .01).
  
  
  CONCLUSIONS
  Successful filtration surgery results in both lower IOP and less positional IOP change compared with medically treated eyes. Bleb features associated with smaller positional IOP change include higher elevation, microcysts, and less vascularity.
authors.affiliation: Department of Ophthalmology and Visual Sciences, Kellogg Eye Center, University of Michigan, Ann Arbor, Michigan 48105, USA. jweizer@umich.edu
authors.forename: Jennifer S
authors.initials: JS
authors.lastname: Weizer
authors.forename: Anju
authors.initials: A
authors.lastname: Goyal
authors.forename: Patricia
authors.initials: P
authors.lastname: Ple-Plakon
authors.forename: Agnieszka
authors.initials: A
authors.lastname: Trzcinka
authors.forename: Bradley D
authors.initials: BD
authors.lastname: Strong
authors.forename: Christina A
authors.initials: CA
authors.lastname: Bruno
authors.forename: Justin
authors.initials: J
authors.lastname: Junn
authors.forename: Irene
authors.initials: I
authors.lastname: Tseng
authors.forename: Leslie M
authors.initials: LM
authors.lastname: Niziol
authors.forename: David C
authors.initials: DC
authors.lastname: Musch
authors.forename: Sayoko E
authors.initials: SE
authors.lastname: Moroi
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003228:Conjunctiva / Q000473:pathology* / Q000601:surgery; D005260:Female; D018463:Filtering Surgery; D005901:Glaucoma / Q000503:physiopathology / Q000601:surgery*; D006801:Humans; D007429:Intraocular Pressure / Q000502:physiology*; D008297:Male; D008875:Middle Aged; D016683:Supine Position / Q000502:physiology*; D014065:Tonometry, Ocular; D014792:Visual Acuity / Q000502:physiology; D055815:Young Adult