Posterior-to-anterior tibial artery peak systolic velocity ratio (PT:AT) showed a moderate-to-strong positive correlation with foveal avascular zone enlargement (r = 0.471, p = 0.0086), while ankle-brachial index showed no significant association (r = -0.024, p = 0.901) in adults with type 2 diabetes.
Observational (n=30)
No
Does the peak-systolic velocity of posterior/anterior tibial artery ratio (PT:AT) correlate better with foveal avascular zone enlargement than ABI in patients with type 2 diabetes?
Velocity-based tibial hemodynamics (PT:AT) correlate significantly with retinal microvascular damage in type 2 diabetes, unlike traditional pressure-based ABI, suggesting its potential utility as a complementary screening tool.
Effect estimate: r 0.471 for PT:AT; r -0.024 for ABI (95% CI 95% CI [0.13, 0.71] for PT:AT; 95% CI [-0.38, 0.34] for ABI)
Absolute Event Rate: 0.471% vs -0.024%
p-value: p=0.0086 for PT:AT; 0.901 for ABI
(1) Background: Diabetic retinopathy and peripheral arterial disease co-occur through shared endothelial pathophysiology. Ankle-brachial index (ABI), the standard peripheral screening tool, demonstrates poor sensitivity (35%) in diabetic cohorts due to medial arterial calcification. We comparatively assessed the association of peak-systolic velocity of posterior/anterior tibial artery ratio (PT:AT) versus that of traditional pressure-based (ABI) with foveal avascular zone (FAZ), a marker of retinal ischemia, and thus hypothesized that PT:AT would demonstrate stronger association with FAZ compared to ABI in our cohort. (2) Methods: Cross-sectional pilot study of 30 type 2 diabetes mellitus patients. We aimed to enhance the robustness of our results using five convergent statistical methods. (3) Results: PT:AT showed strong association with FAZ (r = 0.471, p = 0.0086, 95% CI 0.13, 0.71), with convergent evidence across all five analytical methods. ABI showed no effect (r = −0.024, p = 0.901, 95% CI −0.38, 0.34). We showed that velocity-based metrics identify microvascular dysfunction, whereas the pressure-based ABI does not. The mediation analysis showed that the relation of PT:AT to FAZ is not significantly mediated by the resistivity index of ophthalmic artery. (4) Conclusions: In this pilot study, velocity-based tibial hemodynamics showed a stronger cross-sectional relationship with retinal microvascular damage compared to pressure-based ABI. These preliminary findings suggest PT:AT assessment may complement ABI screening in diabetic foot clinics to identify patients requiring intensive retinal surveillance. Multicenter validation is required before clinical implementation.
Ladea et al. (Tue,) conducted a observational in Adults with type 2 diabetes mellitus diagnosed according to ADA criteria with disease duration >5 years and moderate glycemic control (mean HbA1c 7.2%), enrolled from a diabetic foot clinic in Romania, with visual acuity 0.1 or better, without type 1 diabetes, no prior vitreoretinal surgery or severe peripheral vascular disease precluding ultrasound (n=30). Assessment of posterior-to-anterior tibial artery peak systolic velocity ratio (PT:AT) vs. Ankle-brachial index (ABI) was evaluated on Correlation between PT:AT ratio and foveal avascular zone (FAZ) area as marker of retinal microvascular damage (r 0.471 for PT:AT; r -0.024 for ABI, 95% CI 95% CI [0.13, 0.71] for PT:AT; 95% CI [-0.38, 0.34] for ABI, p=0.0086 for PT:AT; 0.901 for ABI). Posterior-to-anterior tibial artery peak systolic velocity ratio (PT:AT) showed a moderate-to-strong positive correlation with foveal avascular zone enlargement (r = 0.471, p = 0.0086), while ankle-brachial index showed no significant association (r = -0.024, p = 0.901) in adults with type 2 diabetes.