Vascular Insufficiency May Accelerate Progression in NTG Patients

Early intervention is effective at reducing retinal thickening and improving visual outcomes in diabetic retinopathy and diabetic macular edema, underlining the importance of prompt detection of disease and structural damage. Photo: Lee Vien, OD, and David Yang, OD. Click image to enlarge. In a recent study, Korean researchers aimed to investigate the relationship between nocturnal blood pressure (BP) dip and rapid central visual field (VF) progression in patients with early-to-moderate stage normal-tension glaucoma (NTG). They found that those who had more than a 20% nocturnal blood pressure dip in 24 hours—known as “over-dippers”—showed significantly more rapid VF progression, which warrants 24-hour ambulatory BP monitoring, according to the researchers.In total, 199 untreated normotensive glaucoma patients underwent 24-hour ambulatory BP monitoring with a minimum two-year follow-up. Based on their nocturnal blood pressure changes, patients were classified as:non-dippers: <10% change (45.7%)dippers: 10% to 20% MAP dip (34.2%)over-dippers: more than a 20% MAP dip (20.1%)Subjects who demonstrated negative nocturnal mean arterial pressure (MAP) were also considered to be non-dippers.The rates of central visual field changes over time among these groups were compared using linear mixed model analysis. Fast central VF progression was defined as a decline in the mean total deviation values of 12 central points at a rate of <-0.5 dB/year. Logistic regression analysis identified clinical factors, including nocturnal BP dip, that contribute to accelerated central VF progression.Over-dippers showed significantly faster central VF progression than non-dippers and dippers, with over 50% experiencing fast progression. Rapid progression was significantly associated with the percentage of nocturnal MAP dip in eyes with early-to-moderate stage NTG. A greater degree of nocturnal hypotension was identified as an independent predictor of fast central VF progression in patients with NTG.Central visual field progression in over-dipper eyes may be linked to vascular insufficiency of the optic nerve head, potentially due to increased fluctuations in 24-hour systemic blood pressure and lower nocturnal MAP minimum. “Supporting this hypothesis, glaucoma patients with signs of vascular insufficiency—such as hypotension, migraines, Raynaud’s phenomenon and sleep apnea—are frequently observed among early-stage glaucoma patients with central VF scotomas,” the researchers wrote in their paper. “Additionally, patients with NTG who experience significant fluctuations in ocular perfusion pressure due to excessive nocturnal BP dips may exhibit central VF scotomas.”Another possible explanation for the faster progression in field loss observed in the over-dippers may be the lower variability of central grid locations compared to peripheral ones, allowing for earlier detection of significant VF changes, the authors noted, which may be particularly relevant because over-dippers often present with a higher prevalence of central VF scotomas.No significant differences were observed in the prevalence of fast global VF progression among the groups, suggesting that the impact of nocturnal BP dips is more pronounced in the central visual field.Although no significant differences were found in 24-hour IOP parameters categorized by nocturnal BP dip, significant differences were observed in 24-hour BP parameters, including diurnal MAP maximum/range, nocturnal MAP mean, nocturnal MAP minimum, nocturnal MAP range and nocturnal MAP dip percentage, which are consistent with findings from recent studies. Increased fluctuations may increase the vulnerability of target organs—including the optic nerve head—through ischemia-reperfusion damage mechanisms, and these characteristics may represent risk factors contributing to central VF progression in over-dipper patients with NTG, the authors explained in their paper.The results of these findings suggest that clinicians should closely monitor the central visual field in over-dippers, as they are at increased risk for rapid progression—a change that may be overlooked when relying solely on global VF indices. “Given the strong correlation between fast central VF loss and impaired vision-related quality of life and functional disability, performing 24-hour ambulatory BP monitoring is recommended for NTG patients who exhibit rapid central VF progression, despite seemingly well-controlled IOP,” the authors concluded in their paper.Click here for the journal source. Park J, Song WK, Yoon J, et al. Fast central visual field progression in patients with normal-tension glaucoma and nocturnal blood pressure dip. Am J Ophthalmol. September 13, 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.