Optical Coherence Tomography Angiography Biomarkers Predict Anatomical Response to Bevacizumab in Diabetic Macular Edema

Figures & data

Table 1 Baseline Demographic Characteristics

	All Eyes	Early Response Eyes	Treatment Refractory Eyes	p-value^a
No. of eyes	36	18	18
Mean age, years (±SD)	54.4 (±6.7)	52.4 (±7.3)	56.4 (±5.6)	0.073
Female, n (%)	20 (56)	11 (61)	9 (50)	0.502
DM Type, n (%)				0.630
Type 1	5 (14)	2 (11)	3 (17)
Type 2	31 (86)	16 (89)	15 (83)
DM duration, years (±SD)	16 (±6)	14 (±6)	18 (±6)	0.055
DM treatment, n (%)				0.611
Insulin	28 (78)	13 (72)	15 (83)
Oral drugs	8 (22)	5 (28)	3 (17)
HbA1C, % (±SD)	7.8 (±1.8)	7.7 (±2.2)	7.9 (±2.1)	0.630
Hypertension, n (%)	17 (47)	8 (44)	9 (50)	0.738
Retinopathy grade, n ()				0.903
Mild NPDR	7 (19.5)	3 (17)	4 (22)
Moderate NPDR	14 (39)	8 (44)	6 (34)
Severe NPDR	7 (19.5)	3 (17)	4 (22)
PDR	8 (22)	4 (22)	4 (22)
Lens status, n (%)				0.185
Nuclear sclerosis	34 (95)	16 (89)	18 (100)
Pseudophakia	2 (6)	2 (11)	0 (0)

Note: ^aComparison of early response with treatment refractory eyes.

Abbreviations: DM, diabetes mellitus; NPDR, non-proliferative diabetic retinopathy; PDR, proliferative diabetic retinopathy.

Table 2 Comparison of Pretreatment and Post-Treatment OCTA Metrics in All Included Eyes

	Pretreatment	Post-Treatment	Change	p-value
LogMAR BCVA	0.67 ± 0.35	0.46 ± 0.26	−0.21 ± 0.27	<0.001^a
CMT, µm	423 ± 131	332 ± 98	−89 ± 137	<0.001^a
PFT, µm	414 ± 79	364 ± 46	−50 ± 75	<0.001^a
FAZ area, mm^2	0.362 ± 0.108	0.398 ± 0.163	0.036 ± 0.099	0.030^a
SCP VD, %
Whole image	41.62 ± 4.28	40.96 ± 5.11	−0.66 ± 3.32	0.240
Fovea (central 1 mm)	22.42 ± 7.34	18.63 ± 7.26	−3.79 ± 6.38	0.001^a
Parafovea (total)	41.34 ± 5.70	40.03 ± 6.29	−1.31 ± 4.12	0.064
Temporal parafovea	42.7 ± 5.26	40.68 ± 6.17	−2.03 ± 4.83	0.017^a
Superior parafovea	41.18 ± 6.44	40.1 ± 7.14	−1.08 ± 4.52	0.162
Nasal parafovea	40.16 ± 7.13	39.23 ± 6.40	−0.93 ± 5.76	0.340
Inferior parafovea	41.35 ± 6.48	40.13 ± 7.82	−1.23 ± 4.86	0.141
Perifovea (total)	41.64 ± 3.98	40.71 ± 4.17	−0.93 ± 3.14	0.133
DCP VD, %
Whole image	41.56 ± 2.69	41.34 ± 3.19	−0.23 ± 3.50	0.741
Fovea (central 1mm)	29.24 ± 6.79	26.96 ± 6.84	−2.29 ± 6.53	0.075
Parafovea (total)	46.5 ± 4.54	46.58 ± 3.23	0.08 ± 3.96	0.920
Temporal parafovea	48.01 ± 4.21	47.71 ± 3.86	−0.3 ± 3.70	0.672
Superior parafovea	45.02 ± 5.36	45.65 ± 3.47	0.63 ± 4.97	0.511
Nasal parafovea	46.42 ± 5.69	47.41 ± 4.56	0.99 ± 4.66	0.270
Inferior parafovea	46.58 ± 5.39	45.57 ± 3.83	−1.01 ± 5.98	0.381
Perifovea (total)	42.37 ± 3.02	42.04 ± 3.54	−0.35 ± 4.04	0.652

Note: ^aStatistically significant difference, ie p < 0.05.

Abbreviations: OCTA, Optical Coherence Tomography Angiography; BCVA, best-corrected visual acuity; CMT, central macular thickness; DCP, deep capillary plexus; FAZ, foveal avascular zone; PFT, parafoveal thickness; SCP, superficial capillary plexus; VD, vascular density.

Table 3 Comparison of Pretreatment and Post-Treatment OCTA Metrics Between Groups

	Pretreatment			Post-Treatment
	Early Response Eyes (n=18)	Treatment Refractory Eyes (n=18)	P-value	Early Response Eyes (n=18)	Treatment Refractory Eyes (n=18)	p-value
LogMAR BCVA	0.84±0.41	0.51±0.15	0.004^a	0.48±0.33	0.44±0.15	0.612
(ETDRS letters)	(43.2±20.5)	(59.7±7.5)		(60.7±16.6)	(62.9±7.8)
CMT, µm	490±135	353±70	0.001^a	306±77	359±91	0.108
PFT, µm	456±88	371±33	0.001^a	355±50	372±42	0.283
FAZ area, mm^2	0.309±0.098	0.413±0.095	0.003^a	0.346±0.107	0.451±0.193	0.053
SCP VD, %
Whole image	42.87±4.49	40.37±3.77	0.080	43.03±5.78	38.89±3.35	0.013^a
Fovea (central 1 mm)	24.86±6.90	19.98±7.13	0.045^a	20.7±7.00	16.6±7.10	0.087
Parafovea (total)	43.49±5.51	39.19±5.19	0.021^a	42.64±7.01	37.43±4.22	0.011^a
Temporal parafovea	44.65±5.04	40.75±4.86	0.024^a	43.44±6.16	37.93±4.95	0.006^a
Superior parafovea	44.14±6.08	38.22±5.47	0.004^a	43.41±7.78	36.8±4.61	0.004^a
Nasal parafovea	42.16±6.29	38.17±7.53	0.094	41.21±7.46	37.25±4.51	0.063
Inferior parafovea	43.06±7.16	39.65±5.39	0.115	42.49±8.13	37.76±6.93	0.069
Perifovea (total)	42.25±4.46	41.19±3.65	0.494	41.79±4.80	39.91±3.57	0.244
DCP VD, %
Whole image	42.07±2.36	41.18±2.92	0.398	41.7±3.18	41.06±3.27	0.610
Fovea (central 1mm)	32.30±4.88	26.95±7.25	0.028^a	28.9±7.20	25.5±6.40	0.198
Parafovea (total)	46.98±4.43	46.14±4.73	0.641	46.38±2.03	46.73±3.97	0.783
Temporal parafovea	49.32±4.12	47.03±4.13	0.159	47.64±3.45	47.76±4.25	0.936
Superior parafovea	45.58±5.66	44.61±5.27	0.642	45.49±3.24	45.77±3.74	0.839
Nasal parafovea	46.45±5.55	46.39±5.98	0.980	47.07±2.85	47.66±5.60	0.739
Inferior parafovea	46.58±5.26	46.58±5.66	0.997	45.33±3.70	45.75±4.03	0.777
Perifovea (total)	42.82±2.95	42.04±3.13	0.510	42.4±3.37	41.73±3.75	0.630

Note: ^aStatistically significant difference, ie, p < 0.05.

Abbreviations: OCTA, optical coherence tomography angiography; BCVA, best- corrected visual acuity; CMT, central macular thickness; DCP, deep capillary plexus; FAZ, foveal avascular zone; PFT, parafoveal thickness; SCP, superficial capillary plexus; VD, vascular density.

Figure 1 Comparison of area under receiver operating characteristic curve between the starting CMT (blue) versus the full predictive model (green) for discriminating eyes with an early treatment response from those without.