During any given clinic day, I can expect to be asked a version of this question from one of my patients. Whether patients return to follow-up confident that their intraocular pressure (IOP) is going to be elevated because their blood pressure has been high, or they were recently diagnosed with high blood pressure and are concerned about getting glaucoma, the underlying patient concern is the same. Who can blame them? Both glaucoma and systemic hypertension have similar risk factors and patient demographics, so a large majority of our patients suffer from both. These patients go to many different physicians in various specialties who manage and control their “pressure.” Naturally patients assume they’re related, and they want to know how.

Ophthalmologists and glaucoma specialists have been asking this same question for years. The Rotterdam and Beaver Dam eye studies reported a higher risk of primary open-angle glaucoma with high blood pressure, whereas the Barbados Eye Study has reported the opposite.¹ There are complex interactions between blood pressure and IOP, which can influence glaucoma development. High blood pressure could potentially increase IOP by increased production of aqueous humor by means of elevated ciliary blood flow and capillary pressure and decrease of aqueous outflow as a result of increased episcleral venous pressure.² So how do you address this question that at best has a muddled answer?

In general, I see this as a teaching moment, an opportunity to further discuss with patients the various aspects of their disease and our treatment plan. I explain that although there is some thought that they are related, there is no consensus in clinical studies showing that elevated blood pressure causes elevated IOP. I then use this time to go over how, in reality, low blood pressure has been more consistently shown to worsen glaucoma, especially in normal-tension glaucoma.³ I stress that what is important is that patients work with their primary care clinicians and cardiologists to optimize their cardiovascular risk factors. I typically transition the conversation to the importance of compliance and follow-up for both chronic conditions. Although there is no consensus for a direct correlation between them, both uncontrolled hypertension and uncontrolled glaucoma can lead to retinal vein occlusions, which in turn can lead to acute neovascular glaucoma.⁴ We then review their blood pressure medications and discuss if they are taking them at night. If they are, I recommend conferring with their primary care physician or cardiologist regarding switching to a morning regimen to avoid nocturnal hypotension. Lastly, I remind them that healthy diet and exercise can be beneficial for both diseases. I further explain that while exercise and especially aerobic exercise are good,⁵ I advise against the head-down positioning in some yoga poses that have been shown to elevate IOP.⁶

In the end, although there is no consensus regarding a correlation between elevated blood pressure and elevated IOP, this scenario provides a great opportunity for clinicians to have a discussion with patients anout their health care. By helping them better understand their disease and empowering them to be involved in their care, clinicians can help prevent permanent vision loss. GP

Paul Petrakos, DO, is an assistant professor of ophthalmology at Weill Cornell Medicine in New York, New York. He reports no related disclosures. Reach him at pap9072@med.cornell.edu.

References

1. Asefa NG, Neustaeter A, Jansonius NM, Snieder H. Autonomic dysfunction and blood pressure in glaucoma patients: the Lifelines cohort study. Invest Ophthalmol Vis Sci. 2020;61(11):25. doi:10.1167/iovs.61.11.25
2. Leeman M, Kestelyn P. Glaucoma and blood pressure. Hypertension. 2019;73(5):944-950. doi:10.1161/HYPERTENSIONAHA.118.11507
3. Charlson ME, de Moraes CG, Link A, et al. Nocturnal systemic hypotension increases the risk of glaucoma progression. Ophthalmology. 2014;121(10):2004-2012. doi:10.1016/j.ophtha.2014.04.016
4. Kolar P. Risk factors for central and branch retinal vein occlusion: a meta-analysis of published clinical data. J Ophthalmol. 2014;2014:724780. doi:10.1155/2014/724780
5. Schmidt KG, Mittag TW, Pavlovic S, Hessemer V. Influence of physical exercise and nifedipine on ocular pulse amplitude. Graefes Arch Clin Exp Ophthalmol. 1996;234(8):527-532. doi:10.1007/BF00184863
6. Jasien JV, Jonas JB, de Moraes CG, Ritch R. Intraocular pressure rise in subjects with and without glaucoma during four common yoga positions. PLoS One. 2015;10(12):e0144505. Published 2015 Dec 23. doi:10.1371/journal.pone.0144505