Plateau iris in Asian subjects with primary angle closure glaucoma.

OBJECTIVE: To determine the prevalence of plateau iris in Asian eyes with primary angle closure glaucoma (PACG) using ultrasound biomicroscopy (UBM). METHODS: In this cross-sectional observational study, subjects older than 40 years with PACG who had a patent laser peripheral iridotomy underwent UBM in 1 eye. Ultrasound biomicroscopy images were qualitatively analyzed using standardized criteria. Plateau iris in a quadrant was defined by anteriorly directed ciliary body, absent ciliary sulcus, steep iris root from its point of insertion followed by a downward angulation, flat iris plane, and irido-angle contact. At least 2 quadrants had to fulfill these UBM criteria for an eye to be classified as having plateau iris. RESULTS: One hundred eleven subjects (70 from Singapore, 41 from Thailand) with PACG were recruited. The mean (SD) age was 65.6 (8.1) years, and 63.9% were female. Based on standardized UBM criteria, plateau iris was found in 36 of 111 eyes (32.4%; 95% confidence interval, 24.4%-41.6%). In these 36 eyes, quadrant-wise analysis showed 66.7% had plateau iris in 2 quadrants; 22.2%, in 3 quadrants; and 11.1%, in all quadrants. CONCLUSIONS: About 30% of PACG eyes with a patent laser peripheral iridotomy were found to have plateau iris on UBM, highlighting the importance of non-pupil block mechanisms in Asian individuals.

Confirmation of the presence of uveal effusion in Asian eyes with primary angle closure glaucoma: an ultrasound biomicroscopy study.

OBJECTIVE: To confirm the presence of uveal effusion in the eyes of Asian patients with primary angle closure glaucoma (PACG) using ultrasound biomicroscopy (UBM). METHODS: In this observational case series, 70 patients with PACG (28 untreated patients with newly diagnosed PACG and 42 patients who had undergone previous laser iridotomy and were being monitored) and 12 patients with acute primary angle closure (APAC) were recruited. Eyes of patients with newly diagnosed PACG and APAC underwent UBM before and after laser iridotomy, whereas eyes of patients with treated PACG underwent UBM at enrollment. Uveal effusion was defined as a clear space between the choroid and sclera and was graded as follows: grade 0, none; grade 1, slitlike; grade 2, bandlike; and grade 3, obvious. RESULTS: Overall, uveal effusion was found in 11 of 70 eyes with PACG (15.7%; 95% confidence interval, 8.8%-26.2%) and in 3 of 12 eyes with APAC (25%; 95% confidence interval, 8.0%-53.4%). For patients with newly diagnosed PACG, uveal effusion was found in 4 of 28 eyes (14.2%; 95% confidence interval, 5.1%-32.1%) before laser iridotomy; 2 eyes had effusion after laser iridotomy. When present, the effusion was grade 1 in PACG eyes and grade 2 or 3 in APAC eyes. CONCLUSIONS: Uveal effusion was present in a significant proportion of Asian eyes with PACG and APAC, confirming a recent report of this finding.