• PAC Suspects: LPI Versus Initial Observation

    By Lynda Seminara
    Selected by Stephen D. McLeod, MD

    Journal Highlights

    Ophthalmology, February 2022

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    In the Zhongshan Angle Closure Prevention (ZAP) trial, the incidence of primary-angle closure (PAC) was less than 7% within six years of iden­tification as PAC suspects (PACS) by community screening. Baskaran et al. conducted a similar study in Singapore and found that the incidence of PAC and PAC glaucoma (PACG) was low throughout five years of follow-up. Eyes treated with laser peripheral iridotomy (LPI) fared better overall.

    For this Singapore trial, the re­searchers prospectively evaluated 480 adults over 50 years of age who had received a diagnosis of PACS. PACS was defined as gonioscopy findings of two or more quadrants of apposition­al angle closure. All participants had bilateral asymptomatic disease; each underwent prophylactic LPI in one eye (selected randomly), and their fellow eyes served as the controls. The main endpoint was the development of PAC or PACG in either eye during five years of annual follow-up.

    The study population was primarily Chinese (92.7%) and female (75.8%); the mean age was 62.8 years. Within five years, the eyes treated with LPI were less likely than control eyes to experience either PAC or PACG (5% in LPI patients vs. 9.4% in controls). The adjusted hazard ratio for progression to PAC among LPI-treated eyes, relative to controls, was .55. However, the overall progression rate was low, and there was no difference in the risk of developing PACG between groups. Older patients and eyes with high IOP at baseline were more likely to reach an endpoint.

    The authors concluded by noting that their findings further support the recom­mendation that observation without LPI is a reasonable option for PACS. (Also see related commentary by Ying Han, MD, PhD, in the same issue.)

    The original article can be found here.