Study Describes Complex Role of BP in POAG Risk Among Black Patients

These results reveal a delicate balance in which both high IOP and lower systemic BP levels could influence the risk of developing POAG. Photo: Michael Chaglasian, OD. Click image to enlarge. Individuals of African ancestry are disproportionately more likely to develop glaucoma than those of European descent—up to five times higher—and those with glaucomatous risk factors are nearly twice as likely to convert. The reasons behind this are unclear, however. So, in a recent study, researchers from the University of Pennsylvania sought to identify risk factors associated with conversion from glaucoma suspect to active POAG among Black Americans. They found that, in these individuals, a higher risk of POAG conversion is independently associated with two straightforward variables—higher intraocular pressure (IOP) and presence of myopia—and a less predictable one: blood pressure (BP). The findings were reported last week in American Journal of Ophthalmology.A total of 330 glaucoma suspects from the Primary Open-Angle African American Glaucoma Genetics study were included, with a median follow-up of 6.71 years. Participants were classified as glaucoma suspects if they met at least one of the following criteria: (1) elevated IOP, (2) suspicious optic nerve head or retinal nerve fiber layer (RNFL) appearance or (3) suspicious visual field results.The authors found that 13.6% of African ancestry glaucoma suspects converted to POAG over 6.7 years and elevated IOP (≥21mm Hg) was associated with 2.5-fold increased conversion risk, underscoring the importance of IOP monitoring in managing glaucoma suspects and aligns with established knowledge about the role of IOP in glaucoma pathogenesis. “Clinicians should consider more aggressive IOP-lowering interventions in suspects with elevated IOP,” the authors wrote in their paper.They also found that the absence of hypertension was associated with 2.4-fold increased conversion risk, which highlights the complex relationship between systemic blood pressure and glaucoma progression. “Our findings align with evidence that supports a “U-shaped” relationship between blood pressure and glaucoma prevalence, where both very low and excessively high blood pressure may increase risk, but mild hypertension could be protective due to improved optic nerve perfusion,” the authors explained in their paper.A previous study suggested that systemic blood pressure plays an important role in maintaining normal autoregulation of the optic nerve head; thus, lower blood pressure could lead to increased risk of developing POAG. Compared to individuals of European descent, studies suggest individuals of African descent may have lower retrobulbar blood flow and lower perifoveal and macular vessel density. The authors of the present study say this could lead to a reduction in perfusion and delivery of essential nutrients to the optic nerve, thus contributing to glaucoma progression.Myopia was associated with 2.4-fold increased conversion risk, which aligns with previous studies. “Given this risk, comprehensive eye exams for glaucoma suspects should include careful assessment of refractive error. Myopic patients may require more frequent monitoring or earlier intervention,” the authors wrote in their paper.The mechanisms underlying this association may involve biomechanical changes in the optic nerve head or alterations in the lamina cribrosa associated with myopic eyes, the authors explained. “A prior study of myopic children found that axial elongation in myopia is associated with a nasal shift and elongation of the lamina cribrosa, which can lead to increased vulnerability to glaucomatous damage.”Univariate analyses also showed associations between certain RNFL characteristics and conversion risk, such as greater inter-eye difference in RNFL thickness.Importantly, the authors explained, is that this relatively high conversion rate of 13.6% reinforces the need for vigilant monitoring and proactive care management—particularly for patients of African ancestry, who not only have a higher risk of developing POAG but also experience more rapid disease progression and are more likely to suffer severe and earlier VF damage or blindness. “This increased vulnerability is likely multifaceted and includes genetic predisposition, differences in ocular structure (including thinner corneas and larger optic discs) and challenges in socioeconomic status,” the authors wrote.Click here for the journal source. Fedtke C, Chen Z, Tilia D, et al. STOP kit for myopia control: Stage 1 results from a randomized controlled clinical trial in Chinese children. Ophthalmol. August 7, 2025. [Epub ahead of print]. This article was developed by the editorial staff in conjunction with experts in the field. In the process, AI may have been among the editorial tools used to meet the goals of human editors, who approved all content.