Objective: To investigate the long-term outcomes of laser peripheral iridotomy (LPI) on controlling intraocular pressure (IOP) and progression of angle closure in Vietnamese.

Methods: Medical charts of Vietnamese patients who were diagnosed as having primary angle-closure suspect (PACS), primary angle closure (PAC) or primary angle-closure glaucoma (PACG), and who had received LPI at least 10 years prior, in a single private practice were reviewed. The main outcomes included use of further treatments after LPI, progression rate to another classification category and ocular characteristics associated with progression.

Results: 359 patients with a mean follow-up period of 11.8 ± 1.6 years after the LPI were included in this study. The proportion of patients who required additional therapies (medical, laser or surgical) to control IOP were 7.1, 42.4 and 100% in the PACS, PAC and PACG groups, respectively. Fifty-three patients with PACS (22.2%) progressed to PAC; nine patients with PACS (3.8%) progressed to PACG; and five PAC patients (5.2%) progressed to PACG. Cataract surgery was a significant factor associated with PACS eyes without progression (p=0.019).

Conclusions: Further medications, laser or surgery are frequently required to control IOP after LPI for eyes with PAC, especially for eyes with PACG. Lens extraction seems to play a protective role in PACS eyes. Close follow-up after LPI remains necessary to prevent progression of disease.