Evaluation of Microvascular and Visual Acuity Changes in Patients with Early Diabetic Retinopathy: Optical Coherence Tomography Angiography Study

Figures & data

Table 1 Demographic Criteria Among Study Participants

Parameter	Controls (n = 30)	Patients (n = 44)	p-value
Age (years)	41.8 ± 7.6	45.8 ± 9.5	0.17
Gender (female %)	66.7	66.0	0.26
BCVA	0.97 ± 0.08	0.76 ± 0.3	0.01*
CMT (µ)	244.2 ± 15.5	235.3 ± 16.4	0.002**
Vessel density (full)	17.6 ± 1.9	15.4 ± 2.6	0.003**
Perfusion density (full)	42.7 ± 5.1	38.0 ± 6.7	0.01*

Notes: *Statistically significant; **statistically highly significant.

Abbreviations: n, number; BCVA, best-corrected visual acuity; CMT, central macular thickness.

Figure 1 Vessel density, perfusion density, and FAZ metric values compared between a healthy control (A, C, E) and a patient with non-proliferative diabetic retinopathy (B, D, F).

Table 2 Angiographic Values and FAZ Quantitative Parameters of Study Participants in Macula Scans

Vessel density (mm/mm^2)	Parameter	Controls (n = 30)	Patients (n = 44)	p-value
	Central	10.0 ± 3.0	8.5 ± 3.5	0.16
	Inner	17.4 ± 2.3	15.3 ± 2.5	0.004**
	Full	17.6 ± 1.9	15.4 ± 2.6	0.003**
	Outer	18.0 ± 1.8	15.7 ± 2.8	0.003**
Perfusion density (%)	Central	22.0 ± 7.1	19.2 ± 8.8	0.26
	Inner	41.2 ± 5.9	36.9 ± 6.4	0.022*
	Full	42.7 ± 5.1	38.0 ± 6.7	0.014*
	Outer	44.0 ± 4.9	38.9 ± 7.3	0.012*
FAZ	Area	0.20 ± 0.06	0.30 ± 0.08	< 0.001**
	Perimetry	2.1 ± 0.2	2.5 ± 0.3	< 0.001**
	Circularity	0.7 ± 0.09	0.6 ± 0.06	0.003**

Notes: *Statistically significant; **statistically highly significant.

Abbreviations: n, number; BCVA, best-corrected visual acuity; mm, millimeter; mm², millimeter square; %, percentage.

Table 3 Correlation Between Vessel Density and Perfusion Density and FAZ Parameters Among Patients

	FAZ
	Area		Perimeter		Circularity
	r	p	r	p	r	p
Vessel density (mm/mm^2)
Central	−0.03	0.86	−0.04	0.79	0.02	0.88
Inner	−0.04	0.81	−0.08	0.57	0.29	0.05
Outer	−0.05	0.75	−0.09	0.56	0.41	0.006*
Full	−0.03	0.86	−0.09	0.55	0.37	0.013*
Perfusion density (%)
Central	−0.02	0.87	−0.04	0.77	0.04	0.78
Inner	−0.01	0.93	−0.08	0.60	0.23	0.14
Outer	−0.03	0.82	−0.09	0.54	0.36	0.017*
Full	−0.01	0.96	−0.13	0.41	0.35	0.019*

Note: *Statistically significant.

Abbreviations: FAZ, Foveal avascular zone; mm, millimeter; mm², millimeter square; %, percentage.

Figure 2 Positive fair correlation between inner VD and BCVA in patients.

Abbreviations: VD, vessel density; BCVA, best-corrected visual acuity.

Table 4 Correlations Between Macular Vessel Density, Perfusion Density, and FAZ Parameters with BCVA Among Patients

Vessel density (mm/mm^2)	r	p	Perfusion density (%)	r	p	FAZ parameters	r	p
Central	0.15	0.32	Central	0.18	0.24	Area	0.04	0.79
Inner	0.30	0.04*	Inner	0.22	0.15	Perimeter	− 0.10	0.51
Outer	0.25	0.11	Outer	0.23	0.12	Circularity	0.28	0.06
Full	0.24	0.11	Full	0.22	0.14

Note: *Statistically significant.

Abbreviations: FAZ, Foveal avascular zone; mm, millimeter; mm², millimeter square; %, percentage.

Figure 3 Positive fair correlation between outer VD and FAZ circularity index in patients.

Abbreviations: VD, vessel density; FAZ, foveal avascular zone.

Figure 4 Positive fair correlation between full VD and FAZ circularity index in patients.

Abbreviations: VD, vessel density; FAZ, foveal avascular zone.

Figure 5 Positive fair correlation between outer PD and FAZ circularity index in patients.

Abbreviations: PD, perfusion density; FAZ, foveal avascular zone.

Figure 6 Positive fair correlation between full PD and FAZ circularity index in patients.

Abbreviations: PD, perfusion density; FAZ, foveal avascular zone.