ObejctiveTo investigate the consistency and reproducibility of macular perfusion parameters in early diabetic retinopathy (DR) using optical coherence tomography angiography (OCTA).MethodsA prospective cross-sectional observational study. Forty-six patients (46 eyes) diagnosed with mild nonproliferative DR were included in this study. There were 24 males and 22 females, with the mean age of 59.16±10.32 years. Two macular scan sizes of 3 mm×3 mm and 6 mm×6 mm were performed by the same operator, and the same test was performed by another operator. The superficial retinal layer (SRL) and deep retinal layer (DRL) in the foveal avascular zone (FAZ) and vessel density (VD) were quantified. The consistency of the two scan sizes and the reproducibility of the same scan size were also evaluated. The consistency was determined by the intraclass correlation coefficient (ICC). If the intraclass correlation coefficient (ICC)＞0.80, consistency was good; if 0.4≤ICC＜0.8, consistency was general; if ICC＜0.40, consistency was poor.ResultsIn the 3 mm×3 mm and 6 mm×6 mm scanning sizes, the mean results of the two examiners were calculated. The FAZ of SRL were 0.39±0.13 mm2 and 0.42±0.15 mm2, FAZ of DRL were 0.74±0.22 mm2 and 0.89±0.23 mm2. The VD of SRL were (32.23±2.86)% and (31.91±3.01)%, VD of DRL were (43.73±4.64)% and (45.12±5.49)%. The consistency analysis showed that the ICC of SRL-FAZ and DRL-FAZ were 0.920 and 0.812, respectively; the ICC of VD were 0.833 and 0.830, respectively. The consistency was good. The reproducibility analysis of different examiners in the same scan size was better in the consistency of SRL FAZ and VD.ConclusionOCTA in two scanning sizes to measure FAZ and VD of early DR has good consistency and reproducibility.
ObjectiveTo observe the changes of blood flow density and perfusion density in the macula of non-diabetic peritoneal dialysis (PD) patients, and their correlation with blood pressure, total protein, albumin, prealbumin, serum creatinine, urea, and high-sensitivity C-reactive protein were preliminarily analyzed.MethodsA single-center, cross-sectional, clinical observational study. From January to December 2018, 63 eyes of 63 non-diabetic patients (non-diabetic PD group) and 75 eyes of normal healthy people (the normal control group) who underwent PD treatment at the PD Center of Peking University First Hospital were included in the study. All were monocular into the group. Among the 63 patients in the non-diabetic PD group, 24 were males and 39 were females. The duration of PD was 7 to 185 months, with the average duration of 67.87±48.36 months. There were 75 healthy persons in the normal control group. There was no significant difference in age (t=－0.558), sex ratio (χ2=0.492), axial length (t=－1.197), and BCVA between the two groups (P＞0.05). OCT angiography was used to scan the macular area of 3 mm×3 mm and 6 mm×6 mm in the subject’s right eye. The blood flow density and perfusion density of superficial retinal capillaries in the macular area, as well as the area, circumference, and morphological index of the foveal avascular zone (FAZ) were measured. The blood flow density and perfusion density at different locations in the macular area of the two groups of eyes were compared by independent sample t test. The blood pressure, total protein, albumin, prealbumin, serum creatinine, urea, and high-sensitivity C-reactive protein was performed by Pearson correlation analysis.ResultsCompared with the healthy control group, the blood flow density and perfusion density of superficial retinal capillaries in the macular area of the non-diabetic PD group decreased in different scanning ranges with the macular vessel 3×3 center (t=－2.409), the macular vessel 3×3 macular (t=－2.423), macular vessel 3×3 intact (t=－2.759), macular vessel 6×6 intact (t=－1.882), macular vessel 6×6 outer layer (t=－2.188), macular perfusion 3×3 center (t=－1.990), macular perfusion 3×3 complete (t=－2.719), macular perfusion 6×6 complete (t=－2.113), and macular perfusion 6×6 outer layer (t=－2.205). The difference was statistically significant (P＜0.05). The comparison of the macular FAZ area of the two groups of eyes was statistically significant (t=1.985, P＜0.05). Correlation analysis showed that 3×3 macular blood vessels were intact and mean arterial pressure was positively correlated (r=0.256, P=0.043). The macular blood vessels were 3×3 intact, macular perfusion was 3×3 intact, and macular blood was 6×6 intact, which the pre-white protein was positively correlated with (r=0.468, 0.362, 0.333; P＜0.001, P=0.004, 0.008). The macular vessel 3×3 was intact, the macular perfusion 6×6 was intact, which the hypersensitive C-reactive protein was negatively correlated with (r=－0.370, －0.287, P=0.005, 0.030).ConclusionThe superficial retinal blood flow density and perfusion density in the macular area of non-diabetic PD patients are lower than those of normal healthy people.