Non-dipping pattern of nocturnal blood pressure as a risk factor for macular ischemia in branch retinal vein occlusion

Branch retinal vein occlusion (BRVO) is ocular vascular disease affecting approximately 14 million people worldwide, and is closely associated with high blood pressure (BP). Although macular ischemia is a critical factor in the visual prognosis of BRVO, the relationship between macular ischemia and different patterns of nocturnal BP is unknown. Here, we investigated whether a dipping pattern of nocturnal BP is associated with the development of macular ischemia in patients with BRVO. A total of 273 patients were reviewed; of these, 86 (86 eyes) patients were included. All recruited patients had a macular thickness map by optical coherence tomography and underwent 24-h ambulatory BP monitoring. According to their dipping patterns, the participants were divided into dipper and non-dipper groups. The non-dipper group had worse visual outcomes at the initial and 6-month visits (P = 0.014 and P = 0.003, respectively). Five of 32 eyes (15.6%) in the dipper group and 32 of 54 (59.3%) in the non-dipper group had macular ischemia. In a multivariate analysis, the night-to-day systolic BP ratio was associated with the degree of macular ischemia (β = − 0.313, P = 0.004). Thus, a non-dipping pattern may be a risk factor for macular ischemia in patients with BRVO.