. 2021 Sep 16;20(2):1957–1974. doi: 10.1007/s40200-021-00886-0

Table 2.

Main results of the included studies

Article	Normal control eyes		NDR eyes			Mild NPDR eyes			Moderate NPDR eyes			Severe NPDR eyes			PDR eyes
Article	Normal control eyes		NDR eyes			Nonproliferative DR eyes									PDR eyes
Al-Sheikh et al. [44] (2016)	n = 40		NA			n = 10			n = 10			n = 2			n = 6
	FAZ -A (mm²)					FAZ—A (mm²)			FAZ—A (mm²)			FAZ—A (mm²)			FAZ—A (mm²)
	SCP: 0.339 ± 0.118	p = 0.003				SCP: 0.498 ± 0.401		p = 0.301	SCP: 0.444 ± 0.191		p = 0.199	SCP: 0.681 ± 0.006		p < 0.001	SCP: 0.619 ± 0.119		p < 0.001
	DCP: 0.358 ± 0.105	p < 0.001				DCP: 0.608 ± 0.187		p < 0.001	DCP: 0.546 ± 0.250		p = 0.029	DCP: 0.643 ± 0.086		p = 0.001	DCP: 0.734 ± 0.314		p = 0.027
	VD (ratio)					VD (ratio)			VD (ratio)			VD (ratio)			VD (ratio)
	SCP: 0.709 ± 0.038	p < 0.001				SCP: 0.591 ± 0.097		p = 0.004	SCP: 0.566 ± 0.114		p = 0.003	SCP: 0.589 ± 0.0043		p = 0.148	SCP: 0.519 ± 0.081		p = 0.002
	DCP: 0.714 ± 0.049	p = 0.028				DCP: 0.699 ± 0.076		p = 0.544	DCP: 0.649 ± 0.118		p = 0.122	DCP: 0.704 ± 0.079		p = 0.773	DCP: 0.636 ± 0.017		p = 0.136
Bhanushali et al. [45] (2016)	n = 60		NA			n = 35			n = 95			n = 57			n = 22
	FAZ—A (mm²)					FAZ—A (mm²)			FAZ—A (mm²)			FAZ—A (mm²)			FAZ—A (mm²)
	0.38 ± 0.01					0.46 ± 0.03			0.45 ± 0.01			0.46 ± 0.02			0.47 ± 0.02
	VD (%)					VD (%)			VD (%)			VD (%)			VD (%)
	SCP: 49.7 ± 0.55					SCP: 39.2 ± 1.21			SCP: 40.1 ± 0.58			SCP: 38.5 ± 0.76			SCP: 38.9 ± 1.38
	DCP: 53.1 ± 0.73					DCP: 39.7 ± 1.57			DCP: 40.2 ± 0.53			DCP: 39.4 ± 0.68			DCP: 39.2 ± 0.94
Carnevali et al. [46] (2017)	n = 25		n = 25			NA			NA			NA			NA
	FAZ—A (mm²)		FAZ—A (mm²)
	SCP: 0.251 ± 0.104	p = 0.341	SCP: 0.223 ± 0.100		p = 0.341
	DCP: 0.762 ± 0.231	p = 0.808	DCP: 0.747 ± 0.199		p = 0.808
	VD (ratio)		VD (ratio)
	SCP: 0.430 ± 0.020	p = 0.805	SCP: 0.432 ± 0.023		p = 0.805
	DCP: 0.477 ± 0.014	p = 0.005	DCP: 0.464 ± 0.016		p = 0.005
	CC: 0.487 ± 0.015	p = 0.359	CC: 0.490 ± 0.013		p = 0.359
Dimitrova et al. [47] (2017)	n = 33		n = 29			NA			NA			NA			NA
	FAZ—A (mm²)		FAZ—A (mm²)
	SCP: 0.31 ± 0.10	p = 0.02	SCP: 0.37 ± 0.11		p = 0.02
	VD (%)		VD (%)
	SCP: 51.39 ± 13.05	p = 0.04	SCP: 44.35 ± 13.31		p = 0.04
	DCP: 41.53 ± 14.08	p < 0.01	DCP: 31.03 ± 16.33		p < 0.01
Lee et al. [48] (2017)	n = 30		n = 31			n = 26			n = 31						n = 33
	FAZ—A (mm²)		FAZ—A (mm²)			FAZ—A (mm²)			FAZ—A (mm²)						FAZ—A (mm²)
	SCP: 0.325 ± 0.084		SCP: 0.354 ± 0.137			SCP: 0.350 ± 0.114			SCP: 0.431 ± 0.654						SCP: 0.492 ± 0.207
	DCP: 0.797 ± 0.213		DCP: 0.822 ± 0.249			DCP: 0.902 ± 0.294			DCP: 1.174 ± 0.685						DCP: 1.239 ± 0.769
	VD (ratio)		VD (ratio)			VD (ratio)			VD (ratio)						VD (ratio)
	SCP: 0.425 ± 0.028		SCP: 0.408 ± 0.039			SCP: 0.399 ± 0.043			SCP: 0.386 ± 0.043						SCP: 0.355 ± 0.046
	DCP: 0.272 ± 0.057		DCP: 0.267 ± 0.064			DCP: 0.240 ± 0.056			DCP: 0.225 ± 0.054						DCP: 0.193 ± 0.060
Nesper et al.[49] (2017)	n = 44		n = 45			n = 52									n = 40
	FAZ—A (mm²)		FAZ—A (mm²)			FAZ—A (mm²)									FAZ—A (mm²)
	SCP: 0.269 ± 0.086	p < 0.01	SCP: 0.309 ± 0.140		p < 0.01	SCP: 0.356 ± 0.207						p < 0.01			SCP: 0.493 ± 0.238	p < 0.01
	VD (%)		VD (%)			VD (%)									VD (%)
	SCP: 53.59 ± 3.18	p < 0.01	SCP: 53.02 ± 3.11		p < 0.01	SCP: 46.59 ± 4.88						p < 0.01			SCP: 43.43 ± 3.83	p < 0.01
	DCP:60.82 ± 2.44	p < 0.01	DCP: 59.14 ± 2.80		p < 0.01	DCP: 53.76 ± 4.63						p < 0.01			DCP: 49.73 ± 3.66	p < 0.01
Simonett et al. [50] (2017)	n = 23		n = 9			n = 19			NA			NA			NA
	FAZ-A (mm²)		FAZ-A (mm²)
	SCP: 0.26 ± 0.11	p = 0.821	SCP: 0.26 ± 0.12			p = 0.821
	DCP: 0.38 ± 0.15	p = 0.510	DCP: 0.40 ± 0.15			p = 0.510
	VD (%)		VD (%)
	SCP: 51.5 ± 4.0	p = 0.143	SCP: 49.8 ± 4.2			p = 0.143
	DCP: 60.7 ± 2.4	p < 0.001	DCP: 57.0 ± 3.3			p < 0.001
Alam et al. [51] (2018)	n = 40		NA			n = 40			n = 40			n = 40			NA
	FAZ—A (mm²)					FAZ—A (mm²)			FAZ—A (mm²)			FAZ—A (mm²)
	SCP: 0.29 ± 0.16	p = 0.006				SCP: 0.31 ± 0.17	p = 0.006		SCP: 0.36 ± 0.18	p = 0.006		SCP: 0.40 ± 0.21	p = 0.006
	DCP: 0.46 ± 0.17	p = 0.006				DCP: 0.47 ± 0.15	p = 0.006		DCP: 0.52 ± 0.11	p = 0.006		DCP: 0.58 ± 0.26	p = 0.006
	VD (%)					VD (%)			VD (%)			VD (%)
	SCP: 48.16 ± 3.32	p = 0.001				SCP: 45.62 ± 2.11	p = 0.001		SCP: 40 ± 3.52	p = 0.001		SCP: 36.84 ± 2.45	p = 0.001
	DCP: 49.72 ± 3.18	p = 0.001				DCP: 45.98 ± 3.09	p = 0.001		DCP: 41.78 ± 2.17	p = 0.001		DCP: 37.46 ± 3.16	p = 0.001
Cao et al. [52] (2018)	n = 67		n = 71			NA			NA			NA			NA
	FAZ—A (mm²)		FAZ—A (mm²)
	SCP: 0.35 ± 0.09	p = 0.253	SCP: 0.32 ± 0.18	p = 0.253
	VD (%)		VD (%)
	SCP: 55.72 ± 2.43	p < 0.001	SCP: 51.34 ± 4.09	p < 0.001
	DCP: 62.10 ± 2.11	p < 0.001	DCP: 57.66 ± 5.73	p < 0.001
	CC: 66.97 ± 1.23	p = 0.006	CC: 66.36 ± 1.29	p = 0.006
Ciloglu et al. [53] (2019)	n = 45		NA			n = 49									NA
	FAZ—A (mm²)					FAZ—A (mm²)
	SCP: 0.246 ± 0.022	p < 0.001				SCP: 0.438 ± 0.05				p < 0.001
	DCP: 0.342 ± 0.022	p < 0.001				DCP: 0.732 ± 0.06				p < 0.001
	VD (%)					VD (%)
	SCP: 52.17 ± 0.58	p < 0.001				SCP: 45.43 ± 0.56				p < 0.001
	DCP: 60.68 ± 0.90	p < 0.001				DCP: 52.82 ± 0.85				p < 0.001

DCP deep capillary plexus, CC choriocapillaris, FAZ-A foveal avascular zone area, NA not applicable, NDR No Diabetic Retinopathy, NPDR Nonproliferative Diabetic Retinopathy, PDR Proliferative Diabetic Retinopathy, SCP superficial capillary plexus, VD vessel density