Abstract:

 Objective To quantitatively evaluate the long-term changes in anterior segment morphology with ultrasound biomicroscopy (UBM) after laser peripheral iridotomy (LPI) in eyes with primary angle closure suspect (PACS). Design Prospective case series study. Participants 42 PACS consecutive patients in Handan Eye Hospital, Hebei were enrolled. Method LPI was performed in one eye selected randomly for every PACS. Routine ophthalmic tests and UBM examination were performed at presentation and 5 years after LPI. Main Outcome Measures The parameters of anterior chamber angle ahead 500 μm and 750 μm of scleral spur, such as angle opening distance (AOD), trabecular-iris angle (TIA), angle recess area (ARA) trabecular-ciliary process distance (TCPD) and iris thickness (IT) on UBM images. Results The mean follow-up period was (5.2±0.5) years in 42 patients. AOD500, AOD750, TIA500, TIA750, ARA500, and ARA750 were significantly widen at 5 years after LPI than that at presentation in eyes with PACS (all P<0.001). IT500, IT750 were significantly decreased 11% and 6% respectively at 5 years after LPI than that at presentation in eyes with PACS (all P<0.001), and the parameters at 750 μm anterior to the sclera spur were more significantly wide than its 500 μm counterpart. Conclusion LPI can significantly widen the peripheral anterior angle in eyes with PACS and this effectiveness to be sustained at least 5 years after LPI.  (Ophthalmol CHN, 2016, 25: 23-29)

Key words: primary angle closure suspect, laser peripheral iridotomy, ultrasound biomicroscopy