Editors Selection IGR 19-3

Epidemiology: Incidence of Angle-Closure in China

Ningli Wang
Zhang Ye

Comment by Ningli Wang & Zhang Ye on:

77130 Ten-year incidence of primary angle closure in elderly Chinese: the Liwan Eye Study, Wang L; Huang W; Huang S et al., British Journal of Ophthalmology, 2019; 103: 355-360

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This is a nice and important article. The authors reported the ten-year incidence of all forms of primary angle closure (PAC) defined by ISGEO including primary angle closure suspect (PACS), PAC and primary angle-closure glaucoma (PACG) and their risk factors in an urban Chinese population aged 50 years and older. Participants with baseline angle closure or bilateral cataract surgery during the ten-year period were excluded. Occludable angle had invisible posterior pigmented trabecular meshwork for 270° or more in static gonioscopy.

As the authors point out, this is the first population-based study evaluating the incidence of PAC among elderly Chinese people.1With data obtained from 620 participants, the ten-year incidence of PAC was found to be 20.5%, including 16.9%, 2.4% and 1.1% with incident PACS, PAC and PACG in either eye, respectively. The incidence of PAC (2.05% annually) was much higher than that those reported in an Indian population (0.7% annually) aged 40 years and older and in a Greenland Inuit population (1.6% annually), but lower than that in a Mongolian population aged 50 years or older (3.4% versus 2.56% annually) using the same diagnostic standard . This finding supports the notion that East Asians have a higher risk of primary angle closure.

The risk factors for incident PAC were greater baseline lens thickness (LT), shallower anterior chamber depth (ACD) and narrower angle width. Also, a higher incidence was observed in women and in older people. These results are consistent with previous cross-sectional and other longitudinal studies.2-5

Another interesting finding of this study is that none of the ACD, LT and axial length from baseline showed an acceptable sensitivity and specificity in predicting incident PAC spectrum or determining who requires more intensive monitoring.


  1. Quigley HA, Broman AT. The number of people with glaucoma worldwide in 2010 and 2020. Br J Ophthalmol 2006;90:262-267.
  2. Vijaya L, Asokan R, Panday M, et al. Six-year incidence of angle-closure disease in a South Indian population: the Chennai Eye Disease Incidence Study. Am J Ophthalmol 2013;156:1308-1315.
  3. George R, Paul PG, Baskaran M, et al. Ocular biometry in occludable angles and angle closure glaucoma: a population based survey. Br J Ophthalmol 2003;87:399-402.
  4. Kashiwagi K, Chiba T, Mabuchi F, et al. Five-year incidence of angle closure among glaucoma health examination participants. Graefes Arch Clin Exp Ophthalmol 2013;251:1219-1228.
  5. Casson RJ, Baker M, Edussuriya K, et al. Prevalence and determinants of angle closure in central Sri Lanka: the Kandy Eye Study. Ophthalmology 2009;116:1444-1449.

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