Table 2.

Comparison between ETDRS levels using PlexElite 15×9 mm protocol

Metric	Acq. protocol	Area	Healthy			ETDRS10				ETDRS20				ETDRS35				ETDRS43				ETDRS47-53
Vessel density SCP, mm−1	PlexElite 15 mm × 9 mm	Inner ring (5. 10)°	26.2	±	5.9	23.2	±	7.3	0.150	21.3	±	8.6	0.053	22.1	±	4.8	0.000	18.2	±	10.0	0.003	22.9	±	5.1	0.023
		Outer ring (10. 21)°	29.1	±	4.5	26.1	±	6.2	0.030	25.3	±	7.3	0.110	26.3	±	3.5	0.000	22.4	±	8.1	0.001	27.0	±	4.7	0.063
		Extended 1 (21. 31)°	28.2	±	3.1	25.5	±	5.8	0.051	26.1	±	5.5	0.333	26.9	±	2.9	0.016	23.7	±	6.5	0.004	26.9	±	3.1	0.108
		Extended 2 (31. 42)°	23.2	±	2.4	20.7	±	5.6	0.150	21.3	±	4.6	0.200	21.8	±	3.3	0.063	19.6	±	5.0	0.005	21.0	±	2.7	0.014
		Extended 3 (42. 52)°	16.7	±	3.7	16.2	±	6.4	0.922	16.1	±	6.3	0.857	16.9	±	4.0	0.919	13.7	±	6.1	0.134	15.1	±	3.0	0.114
Vessel density DCP, mm−1	PlexElite 15 mm × 9 mm	Inner ring (5. 10)°	23.8	±	7.5	19.9	±	8.2	0.097	17.9	±	10.5	0.053	20.5	±	6.0	0.013	16.7	±	10.4	0.016	19.5	±	6.2	0.014
		Outer ring (10. 21)°	24.9	±	7.2	20.8	±	9.3	0.118	19.4	±	10.6	0.079	20.8	±	6.5	0.011	16.7	±	10.1	0.007	19.4	±	5.4	0.005
		Extended 1 (21. 31)°	22.4	±	6.7	18.6	±	9.3	0.164	18.1	±	9.7	0.224	18.5	±	6.4	0.017	14.4	±	8.5	0.003	15.8	±	5.0	0.001
		Extended 2 (31. 42)°	20.6	±	6.0	17.5	±	9.0	0.354	17.0	±	9.3	0.242	17.1	±	6.3	0.060	13.4	±	7.8	0.007	13.6	±	4.9	0.000
		Extended 3 (42. 52)°	17.3	±	7.0	15.5	±	9.3	0.643	15.0	±	9.3	0.444	14.9	±	6.7	0.269	11.2	±	7.3	0.014	10.0	±	4.0	0.001
Vessel density FR, mm−1	PlexElite 15 mm × 9 mm	Inner ring (5. 10)°	30.8	±	6.4	27.3	±	8.2	0.067	25.2	±	10.2	0.019	27.7	±	5.2	0.000	22.4	±	11.7	0.003	28.0	±	5.3	0.013
		Outer ring (10. 21)°	32.3	±	4.7	29.1	±	7.3	0.019	28.0	±	8.1	0.038	30.1	±	3.9	0.000	25.0	±	9.7	0.001	30.3	±	4.7	0.027
		Extended 1 (21. 31)°	31.0	±	3.5	27.6	±	6.7	0.020	28.2	±	6.3	0.200	29.5	±	3.4	0.014	25.2	±	7.9	0.001	28.7	±	3.2	0.006
		Extended 2 (31. 42)°	27.2	±	3.3	24.1	±	6.9	0.150	24.2	±	5.9	0.105	25.5	±	4.1	0.082	22.2	±	6.4	0.003	23.5	±	3.4	0.001
		Extended 3 (42. 52)°	20.9	±	4.8	20.2	±	7.6	0.884	18.9	±	8.2	0.653	20.6	±	5.3	0.909	16.6	±	7.3	0.064	17.5	±	3.6	0.020
Thickness GCL+IPL, µm	PlexElite 15mm × 9mm	Inner ring (5. 10)°	91.5	±	7.2	88.6	±	10.5	0.407	90.6	±	9.1	0.875	87.7	±	9.3	0.151	87.0	±	13.2	0.399	85.9	±	9.1	0.059
		Outer ring (10. 21)°	62.0	±	4.3	60.5	±	5.8	0.435	64.2	±	5.9	0.301	62.7	±	5.6	0.703	61.7	±	7.5	0.981	61.6	±	6.9	0.980
		Extended 1 (21. 31)°	43.7	±	3.8	44.0	±	3.6	0.678	45.1	±	4.1	0.322	45.0	±	3.3	0.147	45.0	±	6.5	0.779	45.5	±	4.9	0.177
		Extended 2 (31. 42)°	41.0	±	4.1	43.8	±	5.9	0.150	42.5	±	3.7	0.163	44.3	±	4.4	0.003	43.8	±	8.1	0.223	41.5	±	5.1	0.799
		Extended 3 (42. 52)°	35.3	±	3.1	35.4	±	5.1	0.542	37.4	±	6.2	0.192	37.1	±	3.1	0.058	36.3	±	6.2	0.870	37.6	±	5.1	0.161

Data is presented as mean±SD.

Vessel density and GCL+IPL thickness values were calculated using Zeiss PlexElite MultiLayer segmentation algorithm. Comparisons between diabetic individuals and healthy controls were performed using Mann-Whitney U-test. Bonferroni correction was applied to vessel density comparisons setting the statistical significance to p<0.0167, otherwise p<0.05. Statistical significance highlighted in bold and in grey cells.

DCP, deep capillary plexus; FR, full retina; GCL+IPL, ganglion cell layer and inner plexiform layer; SCP, superficial capillary plexus.