Blood pressure levels play a role in glaucoma progression; after adjusting for IOP at follow-up, faster RNFL thickness change rates were found with each 10mm Hg lower mean arterial pressure. Photo: Getty Images.

Vascular factors affecting the blood supply to the eye have long been suspected of playing a role in glaucoma, which could open the door for additional therapy options. When adjusting for IOP, new research suggests lower arterial and diastolic arterial pressures may be closely linked to faster rates of RNFL loss, indicating that levels of systemic blood pressure may play a significant role in glaucoma progression.

Based on these findings, clinicians should be mindful of not only IOP, but also systemic arterial pressure when monitoring the disease state, the study authors explained.

The investigation enrolled roughly 7,500 eyes of about 4,000 subjects from the Duke Glaucoma Registry. The authors investigated the effects of blood pressure on the rate of RNFL loss based on SD-OCT images over time. Other considerations included gender, race, diagnosis, central corneal thickness, follow-up intervals and baseline disease severity. The results were based on 157,291 blood pressure visits, 45,408 IOP readings and 30,238 SD-OCT images.

Overall, the mean rate of RNFL change was -0.70μm/year. Considering follow-up results based on univariable models, the research team found no significant link between RNFL loss and mean arterial pressure, systolic arterial pressure or diastolic arterial pressure.

On the other hand, when adjusting for IOP at follow-up, significantly faster rates of RNFL thickness change over time were found with each 10mm Hg lower mean arterial pressure (-0.06μm/year) and diastolic arterial pressure (-0.08μm/year). However, this result was not mirrored when it came to systolic arterial pressure (-0.01μm/year).

Also of note: arterial pressure effects remained significant after additional adjustment for baseline age, diagnosis, sex, race, follow-up time, disease severity and corneal thickness.

The investigation improved the design of previous studies by looking closely at the direct impact of blood pressure on glaucoma progression, the researchers suggest. Using the large database of patients under routine care, the study was able to derive precise estimates of the independent effect of blood pressure on rates of structural loss in glaucoma, they add.

Jammal AA, Berchuck SI, Mariottoni EB, et al. Blood pressure and glaucomatous progression in a large clinical population. Ophthalmology. August 30, 2021. [Epub ahead of print].