title: Double hump sign in indentation gonioscopy is correlated with presence of plateau iris configuration regardless of patent iridotomy.
abstract: OBJECTIVE
  A plateau iris is one of the clinical forms of angle closure glaucoma. In patients with a patent iridotomy, the double hump sign detected during indentation gonioscopy has been reported to indicate the existence of a plateau iris configuration. The purpose of this study was to determine whether the double hump sign is correlated with the presence of the plateau iris syndrome regardless of the patency of the iridotomy.
  
  
  METHODS
  Five women and 3 men without a patent iridotomy presented with narrow angles on gonioscopy and a double hump sign on indentation gonioscopy. Ultrasound biomicroscopy (UBM) imaging was performed to determine the etiology of the narrow angle and double hump sign, and to determine the appropriate treatment to prevent the progression of visual field damage. Ten patients with narrow angles and without a double hump sign were also examined by UBM to serve as a control group.
  
  
  RESULTS
  All 8 patients who showed double hump sign had a short iris root, which was inserted anterior to the ciliary face, a typical anatomic appearance of a plateau iris. On the other hand, only 1 eye of 10 eyes in control group appeared to have a plateau iris.
  
  
  CONCLUSIONS
  A double hump sign observed on indentation gonioscopy is strongly correlated with the presence of a plateau iris, and therefore a useful indicator of a plateau iris configuration regardless of the patency of a laser iridotomy. Thus, a plateau iris configuration can be detected without using a UBM in many cases.
authors.affiliation: Department of Ophthalmology, Otemae Hospital, Osaka, Japan. ykiuchi@hiroshima-u.ac.jp
authors.forename: Yoshiaki
authors.initials: Y
authors.lastname: Kiuchi
authors.forename: Takashi
authors.initials: T
authors.lastname: Kanamoto
authors.forename: Takao
authors.initials: T
authors.lastname: Nakamura
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D003937:Diagnosis, Differential; D005260:Female; D005500:Follow-Up Studies; D015812:Glaucoma, Angle-Closure / Q000175:diagnosis* / Q000601:surgery; D006068:Gonioscopy / Q000379:methods*; D006801:Humans; D007498:Iris / Q000000981:diagnostic imaging / Q000473:pathology* / Q000601:surgery; D008297:Male; D033401:Microscopy, Acoustic; D008875:Middle Aged; D013508:Ophthalmologic Surgical Procedures / Q000379:methods*; D015203:Reproducibility of Results; D012189:Retrospective Studies; D014792:Visual Acuity