Prevalence of normal-tension glaucoma in the Chinese population: A systematic review and meta-analysis

Author: Zhao J, Solano MM, Oldenburg CE, Liu T, Wang Y, Wang N, Lin SC.

Geographical coverage: China; Singapore; United States of America

Sector: Burden of disease

Sub-sector: Epidemiology; prevalence

Equity focus:  Not reported

Study population: Chinese adults with primary open angle glaucoma (POAG)

Review type: Epidemiology review

Quantitative synthesis method: Meta-analysis

Qualitative synthesis method: Not applicable

Background 

Normal‑tension glaucoma (NTG) is a variant of POAG characterised by glaucomatous optic neuropathy despite normal intra‑ocular pressure. NTG accounts for 52–92 % of POAG cases in Asia, yet its prevalence in Chinese populations is uncertain.

Objectives 

To estimate the prevalence of NTG and the proportion of NTG among POAG in Chinese populations.

Main findings

NTG is common among Chinese patients with POAG, accounting for 70 % of cases.

Twelve studies met the inclusion criteria (nine population‑based, three clinic/network‑based). Among community studies (30 892 participants), pooled NTG prevalence was 1.0 % (95 % CI 1.0–1.0) and POAG prevalence 2.0 % (95 % CI 1.0–2.0). The pooled NTG / POAG proportion was 70.0 % (95 % CI 62.0–77.0). Proportions were lower in clinic‑based datasets. Meta‑regression found no significant effect of age, sex, intra‑ocular pressure or geography, although the NTG proportion tended to decline with age.

Methodology 

PubMed, Wanfang, China National Knowledge Infrastructure and VIP were searched for English‑ or Chinese‑language studies published up to 31 December 2017. Two reviewers screened, extracted data and resolved discrepancies by consensus. Random‑effects meta‑analysis generated pooled estimates; heterogeneity was assessed with the I² statistic.

Applicability / external validity

Heterogeneity between studies and limited international data restrict generalisability. Findings mainly apply to Chinese and similar Asian populations.

Geographic focus

Included studies were conducted in China, Singapore, and United States of America.

Summary of quality assessment

Low confidence: risk of bias was not formally assessed; reviewer numbers for each stage were not specified and excluded‑study lists were absent.

Publication Source:

Zhao J, Solano MM, Oldenburg CE, Liu T, Wang Y, Wang N, Lin SC. Prevalence of Normal-Tension Glaucoma in the Chinese Population: A Systematic Review and Meta-Analysis. Am J Ophthalmol. 2019 Mar;199:101-110. doi: 10.1016/j.ajo.2018.10.017. Epub 2018 Oct 21. PMID: 30352196.

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