Role of hypertension as a risk factor for open-angle glaucoma: a systematic review and meta-analysis

Glaucoma is the leading cause of irreversible blindness. It is estimated that as many as 3.2 million people worldwide experience blindness due to glaucoma, including open-angle glaucoma (OAG). Until now, there is no definite mechanism related to the incidence of OAG. However, increased intraocular pressure (IOP) is considered to be the most important risk factor. Several current studies show that there is a significant relationship between hypertension (HTN) and IOP. In particular, several epidemiological studies have shown that an increase in systemic blood pressure (BP) is associated with an increase in IOP. However, several studies report that high BP provides a protective effect at a young age against the incidence of OAG. Therefore, this literature aims to explore the effect of HTN on the incidence of OAG. In this review, search for the literature using keywords that match the topic, then a gradual screening was carried out with the predetermined eligibility criteria. From 3711 studies, 16 studies matched the criteria having a total sample size of 72 212 and then a quantitative meta-analysis was conducted. The results showed a risk ratio of 1.69 (95% CI 1.50 to 1.90) in the HTN group. However, from our qualitative synthesis, we found that people who have an unstable diastolic blood pressure (DBP), either high or low, are both able to increase the risk of OAG events. In conclusion, we found that HTN was able to increase the risk of OAG and DBP instability, whether high or low, can also increase the risk of OAG incidence.