Migraine as a risk factor for primary open angle glaucoma

Author: Xu C, Li J, Li Z, Mao X.

Geographical coverage: Canada; United States of America; Japan; Australia; Portugal; Denmark; Germany; Taiwan (China)

Sector: Glaucoma

Sub–sector: Risk

Equity focus:  Not reported

Study population: Adults with primary open‑angle glaucoma

Review type: Epidemiology (risk association) review

Quantitative synthesis method: Meta-analysis

Qualitative synthesis method: Not applicable

Background

Primary open‑angle glaucoma (POAG) is a progressive optic neuropathy with risk factors including age, ethnicity, family history, elevated intra‑ocular pressure (IOP) and high myopia. The role of migraine remains controversial.

Objectives 

To determine whether migraine increases the risk of POAG.

Main findings

Migraine is associated with a modest increase in POAG risk, but cohort data are inconclusive.

Eleven studies (eight case–control and three nested case‑control/cohort) published between 1975 and 2016 were included (sample sizes 148–306 692). The pooled relative risk (RR) showed a significant association between migraine and POAG (RR 1.24, 95 % confidence interval 1.12–1.37). Case–control studies demonstrated this relationship, whereas cohort studies did not (RR 1.38, 95 % CI 0.72–2.63).

Methodology 

PubMed, Embase and Web of Science were searched to October 2017 without language restrictions. Two reviewers extracted data and assessed quality using the Sanderson tool for observational studies. Random‑effects meta‑analysis generated pooled RRs; heterogeneity was assessed with χ² and I², and publication bias with Begg and Egger tests.

Applicability / external validity

Few cohort studies with short follow‑up limit causal inference; large longitudinal studies are required.

Geographic focus

Included studies were conducted in Canada, United States of America, Japan, Australia, Portugal, Denmark, Germany, and Taiwan (China).

Summary of quality assessment

We have low confidence in the conclusions of this review due to methodological concerns: reviewer numbers conducting the data extraction and appraisal were unspecified and experts were not consulted as part of the search strategy.