[Quantitative Assessment of Microvascular Changes in Diabetic Retinopathy and Their Association With Blood-Retinal Barrier Impairment].

The majority of DR patients showed abnormal OCTA microvascular parameters, with non-perfusion zone area being the most frequently abnormal indicator.

• 121 cases (58.17%) had abnormal SCP-D (< 45%)
• 114 cases (56.25%) had abnormal DCP-D (< 50%)
• 142 cases (68.27%) had abnormal non-perfusion zone area, making it the most prevalent abnormality
• 88 cases (42.31%) had abnormal FAZ area, 77 cases (37.02%) had abnormal FAZ perimeter, and 69 cases (33.17%) had abnormal FAZ circularity index
• Study included 208 patients with type 2 diabetes and DR

Mean OCTA microvascular parameter values in DR patients were quantified across multiple measures.

• SCP-D was (42.67 ± 4.35)% and DCP-D was (47.89 ± 5.02)%
• FAZ area mean was (0.38 ± 0.10) mm², FAZ perimeter was (2.04 ± 0.28) mm, and FAZ circularity index was 0.72 ± 0.08
• Mean area of the non-perfusion zone was (1.87 ± 0.45) mm²
• Parameters were obtained using OCTA in 208 DR patients

FAZ area was positively correlated with both serum VEGF and ICAM-1 levels.

• FAZ area correlated with VEGF: r = 0.559, 95% CI: 0.457–0.661
• FAZ area correlated with ICAM-1: r = 0.411, 95% CI: 0.289–0.533
• Both VEGF and ICAM-1 serve as markers of blood-retinal barrier disruption
• These positive correlations indicate larger FAZ area is associated with greater BRB impairment

FAZ circularity index, SCP-D, and DCP-D were negatively correlated with serum VEGF and ICAM-1 levels.

• All negative correlations were statistically significant (P < 0.05)
• The non-perfusion zone area was positively correlated with both VEGF and ICAM-1
• These findings indicate that reduced capillary density and FAZ shape irregularity are associated with higher BRB disruption markers

Duration of diabetes and serum VEGF level were identified as independent risk factors for severe retinal microvascular changes.

• Duration of diabetes: OR = 1.159, 95% CI: 1.060–1.267, P < 0.05
• VEGF: OR = 1.013, 95% CI: 1.005–1.022, P < 0.05
• Identified by logistic regression analysis
• Both factors independently predicted severe retinal microvascular changes in DR patients

Among four OCTA assessment indicators, the non-perfusion zone area had the highest predictive value for severe retinal microvascular changes.

• Non-perfusion zone area AUC = 0.879, 95% CI: 0.820–0.938
• Compared against SCP-D, DCP-D, and FAZ parameters as the other three OCTA indicators
• ROC curve analysis was used to evaluate diagnostic efficacy of each indicator
• This finding supports the non-perfusion zone area as the most diagnostically valuable single OCTA parameter in this population