Intraocular pressure spikes after a sequential laser peripheral iridotomy for angle closure.

OBJECTIVE: To determine the incidence of intraocular pressure (IOP) spikes within the first 30 minutes after sequential argon-Nd:YAG laser peripheral iridotomy (LPI) in patients with angle closure and to explore risk factors for their occurrence.

METHODS: A total of 428 consecutive eyes of 298 patients who had undergone LPI at the Singapore National Eye Centre between June 2011 and August 2011 were reviewed retrospectively. There were 238 primary angle closure suspect eyes, 85 primary angle closure eyes, 92 primary angle closure glaucoma eyes, and 13 acute primary angle closure (APAC) eyes. The pre-LPI IOP and post-LPI IOP, gonioscopic findings, medications, laser parameters, and the need for acute IOP-lowering treatment were recorded.

RESULTS: The proportion of patients with a post-LPI IOP elevation ≥8 mm Hg was 10.7% (n=46) and those with a significant IOP spike of ≥30 mm Hg was 31 (7.2%). There were no significant differences between those with or without a post-LPI IOP elevation ≥8 mm Hg and those with or without a post-LPI IOP of ≥30 mm Hg, in terms of age, gender, race, total laser energy used, and seniority of the physician performing the procedure. Patients who experienced IOP spike ≥8 mm Hg were on fewer pre-LPI medications (P=0.009). On logistic regression, patients with APAC had a significantly higher probability of an IOP spike (P=0.003).

CONCLUSIONS: The incidence of postsequential LPI IOP elevation ≥8 mm Hg was 10.7%. The primary diagnosis of APAC was a risk factor, and using preprocedure ocular hypotensives can potentially reduce their occurrence.