A recent cohort study revealed a significant association between long-term blood pressure variability and the progression of visual field loss in patients with glaucoma. The data showed that systemic vascular factors are important in managing glaucoma, particularly in cases where IOP control alone may not suffice.

The study analyzed data from 1,674 eyes of 985 participants with suspected or confirmed glaucoma over a mean follow-up period of 8 years. The cohort included 57.2% female participants, with a mean age of 61.2. Participants were predominantly White (61.7%), followed by Black or African American (32.6%), and Asian (4.5%). They were drawn from the Diagnostic Innovations in Glaucoma Study (DIGS) and the African Descent and Glaucoma Evaluation Study (ADAGES). Key variables included mean blood pressure (BP), BP variability (standard deviation of BP), and mean IOP. Visual field (VF) progression was assessed using the VF mean deviation (MD) slope.

While impacts on glaucoma progression from fluctuations in BP remain unclear, previous studies have shown that “ocular perfusion pressure, which incorporates IOP and BP, was more predictive of glaucoma progression than IOP alone,” the researchers reported in their JAMA Ophthalmology article. Given the association between BP fluctuation and other diseases, the researchers sought to better understand how BP affects VF progression over time.

A 1-mm Hg increase in the standard deviation of mean arterial pressure was associated with a VF MD change of -0.22 dB/year. Similar associations were observed for diastolic arterial pressure, with a VF MD change of -0.16 dB/year per 1-mm Hg higher standard deviation. Higher mean BP and higher BP variability were associated with steeper VF MD slopes, indicating faster VF deterioration. These associations were more pronounced when combined with higher mean IOP, and higher BP variability and higher IOP together resulted in faster VF MD loss.

As the researchers noted, the debate regarding the effects of both high and low BP continues. Some research has indicated that “high BP harms the vasculature and worsens ocular blood flow while simultaneously impairing autoregulatory networks.” However, others “have reported that BP decreases due to antihypertensives reduce blood flow to the eye and that lower ocular blood flow may be associated with glaucomatous development.” The Los Angeles Latino Eye Study even indicated that both hypo- and hypertension may be risk factors for glaucoma. The role of microvascular damage to the optic nerve, retina, and choroid in increased vessel wall stress, ischemia, and inadequate perfusion is also being explored.

While these associations continue to be analyzed, the investigators in this study concluded that the effects of IOP and BP parameters are not distinct from each other. They suggested future studies explore how BP changes affect glaucomatous progression, especially with a more integrated approach to management that includes closer BP and ocular perfusion pressure monitoring.