Table 4

Positive and negative predictive values of the test for limbal chamber depth estimation in detection of gonioscopically occludable angles, primary angle closure, and primary angle closure glaucoma

Limbal chamber depthTraditional gradeAll occludable angles Primary angle closure with or without glaucomaPrimary angle closure glaucoma
0% gradeNA76.494.357.097.527.799.6
⩾5% gradeNA53.197.128.998.99.099.9
⩾15% gradeGrade 129.998.614.899.33.799.9
⩾25% gradeGrade 217.399.98.81002.0100
⩾40% gradeGrade 310.81005.51001.3100
  • Prevalence 6.8%.

  • Primary angle closure, those subjects with angles judged to be occludable on gonioscopic examination with either elevated intraocular pressure, peripheral anterior synechiae or a positive dark room, prone provocation test with or without glaucoma. Prevalence 3.5%.

  • Primary angle closure glaucoma, those subjects with an occludable drainage angle and glaucomatous optic neuropathy, corroborated by visual field evidence in mild or moderate cases. Prevalence 0.8%.