title: Plateau Iris in Primary Angle Closure Glaucoma: An Ultrasound Biomicroscopy Study.
abstract: OBJECTIVE
  To determine prevalence and anterior segment morphology of plateau iris in patients with primary angle closure glaucoma (PACG) after laser peripheral iridotomy using ultrasound biomicroscopy (UBM).
  
  
  METHODS
  In this prospective study, 262 PACG patients and 144 normal controls underwent UBM examination. Plateau iris in a quadrant was defined by the presence of anteriorly directed ciliary process, absent ciliary sulcus, steep iris root from its point of insertion followed by a downward angulation, flat iris plane, and irido-angle contact in the same quadrant. At least 2 quadrants had to fulfill these UBM criteria.
  
  
  RESULTS
  UBM analysis showed plateau iris in 83/262 (31.68%, 95% confidence interval: 26.7%-37.9%) PACG eyes, it was common in female individuals (61.44%), and patients were significantly younger than PACG patients (P=0.006). Plateau iris was found in superior quadrant in 19/83 (22.89%) eyes, inferior quadrant in 19/83 (22.89%) eyes, nasal quadrant in 21/83 (25.3%) eyes, and temporal quadrant in 24/83 (28.91%) eyes. In plateau iris patients, the central anterior chamber depth was shallower, the anterior chamber angle, the scleral-iris angle, and the sclera-ciliary process angle were significantly narrower, and the trabecular ciliary process distance and the iris ciliary process distance were significantly shorter in patients than in PACG subjects.
  
  
  CONCLUSIONS
  Patients with plateau iris had significantly shallow central ACD when compared with those with pupillary block and normal eyes. After laser peripheral iridotomy, about a third of PACG eyes had plateau iris. This is clinically important because these patients can develop synechial angle closure and should be followed up closely.
authors.affiliation: *Department of Glaucoma, Anand Eye Institute, Secunderabad †Pushpagiri eye Institute ‡Department of Biostatistics, National Institute of Nutrition, Hyderabad, Andhra Pradesh, India.
authors.forename: Tarannum
authors.initials: T
authors.lastname: Mansoori
authors.forename: Vijay Kiran
authors.initials: VK
authors.lastname: Sarvepally
authors.forename: Nagalla
authors.initials: N
authors.lastname: Balakrishna
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000867:Anterior Chamber / Q000473:pathology; D002924:Ciliary Body / Q000000981:diagnostic imaging / Q000473:pathology*; D005260:Female; D015812:Glaucoma, Angle-Closure / Q000150:complications* / Q000601:surgery; D006801:Humans; D007429:Intraocular Pressure; D032801:Iridectomy; D007498:Iris / Q000601:surgery; D007499:Iris Diseases / Q000000981:diagnostic imaging / Q000209:etiology*; D017075:Laser Coagulation; D008297:Male; D033401:Microscopy, Acoustic; D008875:Middle Aged; D015995:Prevalence; D011446:Prospective Studies; D014603:Uveal Diseases / Q000000981:diagnostic imaging / Q000209:etiology*; D055815:Young Adult