Five‐year risk of progression of primary angle closure to primary angle closure glaucoma: a population‐based study

Abstract

ABSTRACT.Objective: To report the 5-year progression to primary angle closure glaucoma (PACG) in a population-based cohort of primary angle closure (PAC) subjects. Methods: A total of 37 patients diagnosed as PAC during a population-based study in 1995 were invited for re-examination in 2000. Patients underwent a complete ophthalmic examination including ocular biometry. Progression to PACG was based on optic disc damage and field defects on automated perimetry. Results: In all, 28 of 32 PAC subjects who could be contacted presented for examination. Eight (28.5%; 95% CI 12-45%) had progressed to PACG; two of seven with appositional and six of 21 with synechial closure. All were advised laser peripheral iridotomy (LPI) in 1995; one of the nine who underwent LPI progressed compared to seven of 19 who refused LPI. Four of those originally diagnosed with appositional closure developed peripheral anterior synechiae. One eye of a person previously diagnosed with appositional PAC was reclassified as a primary angle closure suspect (PACS). There was no significant difference in biometric parameters between those who progressed and those who did not. None developed acute PACG or blindness due to glaucoma. Conclusion: In this population-based study of primary angle closure, the 5-year incidence of PACG was eight patients (28.5%; 95% CI 12-45%). We were unable to identify any features that predicted progression.

Angle-closure glaucoma in East Asian and European people. Different diseases?

“…Three broad categories: suspect, established angleclosure and angle-closure glaucoma follow our conceptual model of the natural history, and reflect prognosis for vision. [13][14][15] Within each category, there is a spectrum of severity. Narrower angles are more likely to close than wider angles.…”

UK national survey of prophylactic YAG iridotomy

“…9 Recently, Thomas et al have shown, in an Asian cohort, that 22% of primary angle closure suspects developed raised intraocular pressure (IOP) or synechiae over a 5-year period 10 and in a separate smaller group with known primary angle closure 28.5% progressed to glaucoma as evidenced by disc damage and perimetry defects over the same period. 11 Despite these studies, there is still paucity of larger studies with long-term data on the natural history of treated and untreated narrow angles, particularly among Caucasian populations.…”

Ethnic aspects of acute primary angle closure in a UK mulicultural conurbation

“…Those with an acute, reversible event of elevated intraocular pressure should be considered as having APAC. 10 Based on this classification, manifest PACG prevalence was found to be 0.5% (95% CI 0.1-0.9%) in the VES 11 and 0.7% in the population over 30 years in the Andhra Pradesh Eye Disease Study (95% CI 0.34-1.31%). 2 These rates are comparable to studies from Singapore (0.8%) 12 and Mongolia (0.8%).…”