Association of electroretinogram and morphological findings in central retinal vein occlusion with macular edema

Figures & data

Table 1 Clinical and demographic data of the CRVO patients

Number of eyes (male/female)	16 (5/11)
Age (years)	69.9±11.9
Hypertension	9 (56.3%)
Systolic blood pressure (mmHg)	133±17
Diastolic blood pressure (mmHg)	78±10
Hyperlipidemia	7 (43.8%)
Duration of CRVO (months)	4.8±3.3

Abbreviation: CRVO, central retinal vein occlusion.

Figure 1 Representative fundus color photograph, measurement of retinal thickness by OCT, and an ERG for the same eye.

Notes: (A) A fundus color photograph demonstrating CRVO in a 69-year-old woman. (B) A retinal thickness map obtained by OCT. (C) ERG waveforms (30 Hz flicker waveform on the left and cone waveform on the right) obtained with the le2000 ERG system. Tick marks on the X axis represent 10 ms intervals.
Abbreviations: CRVO, central retinal vein occlusion; ERG, electroretinogram; OCT, optical coherence tomography.

Table 2 Comparison of ERG parameters between the affected eyes and unaffected contralateral eyes of the CRVO patients

	Affected eye	Unaffected eye	P-value
Cone a-wave
Amplitude (μV)	40.8±11.9	44.2±10.4	0.395
Implicit time (ms)	16.4±1.4	15.0±1.6	0.011
Cone b-wave
Amplitude (μV)	131.5±40.1	173.7±33.8	0.003
Implicit time (ms)	35.0±3.4	30.8±1.7	<0.001
Flicker wave
Amplitude (μV)	87.2±28.5	117.3±26.4	0.004
Implicit time (ms)	40.7±3.2	36.1±1.8	<0.001

Abbreviations: CRVO, central retinal vein occlusion; ERG, electroretinogram.

Table 3 Anatomic measurements in the CRVO patients with macular edema

Subfield	Retinal thickness (μm)	Retinal volume (mm^3)
Fovea	686±218	0.55±0.21
Superior inner macula	512±157	0.82±0.28
Superior outer macula	385±158	2.01±0.73
Inferior inner macula	548±142	0.88±0.26
Inferior outer macula	389±150	2.03±0.67
Nasal inner macula	591±227	0.89±0.29
Nasal outer macula	469±237	2.34±0.89
Temporal inner macula	543±202	0.82±0.22
Temporal outer macula	400±220	1.99±0.68

Abbreviation: CRVO, central retinal vein occlusion.

Table 4 Association between ERG parameters and retinal thickness in the nine macular subfields

	Cone a-wave				Cone b-wave				Flicker wave
	Amplitude		Implicit time		Amplitude		Implicit time		Amplitude		Implicit time
	Rc	P-value	Rc	P-value	Rc	P-value	Rc	P-value	Rc	P-value	Rc	P-value
Fovea	−0.14	0.608	0.38	0.142	−0.19	0.480	0.50	0.049	−0.28	0.296	0.50	0.049
Superior inner macula	−0.25	0.346	0.09	0.734	−0.32	0.231	0.50	0.048	−0.27	0.310	0.52	0.040
Superior outer macula	−0.19	0.492	0.33	0.207	−0.47	0.062	0.51	0.041	−0.29	0.266	0.55	0.030
Inferior inner macula	−0.05	0.861	0.25	0.327	−0.17	0.513	0.56	0.023	−0.24	0.363	0.67	0.004
Inferior outer macula	−0.09	0.726	0.31	0.231	−0.48	0.057	0.51	0.044	−0.43	0.094	0.54	0.034
Nasal inner macula	−0.20	0.452	0.31	0.229	−0.51	0.042	0.63	0.009	−0.13	0.633	0.56	0.023
Nasal outer macula	−0.13	0.622	0.46	0.071	−0.54	0.032	0.55	0.028	−0.20	0.449	0.55	0.032
Temporal inner macula	−0.12	0.648	0.24	0.353	−0.13	0.622	0.36	0.168	−0.33	0.202	0.42	0.100
Temporal outer macula	−0.13	0.640	0.44	0.082	−0.32	0.229	0.38	0.136	−0.34	0.192	0.39	0.134

Abbreviations: ERG, electroretinogram; Rc, standard partial regression coefficient.

Table 5 Association between ERG parameters and retinal volume in the nine macular subfields

	Cone a-wave				Cone b-wave				Flicker wave
	Amplitude		Implicit time		Amplitude		Implicit time		Amplitude		Implicit time
	Rc	P-value	Rc	P-value	Rc	P-value	Rc	P-value	Rc	P-value	Rc	P-value
Fovea	−0.15	0.580	0.47	0.068	−0.24	0.367	0.54	0.037	−0.32	0.231	0.62	0.012
Superior inner macula	−0.25	0.343	0.10	0.706	−0.35	0.184	0.50	0.049	−0.31	0.246	0.50	0.049
Superior outer macula	−0.18	0.505	0.33	0.200	−0.47	0.066	0.53	0.036	−0.26	0.334	0.52	0.037
Inferior inner macula	−0.08	0.777	0.26	0.316	−0.23	0.390	0.55	0.027	−0.29	0.282	0.63	0.009
Inferior outer macula	−0.08	0.774	0.32	0.209	−0.43	0.097	0.51	0.043	−0.43	0.100	0.55	0.033
Nasal inner macula	−0.18	0.514	0.30	0.258	−0.50	0.048	0.63	0.009	0.02	0.936	0.58	0.017
Nasal outer macula	−0.09	0.734	0.44	0.086	−0.52	0.037	0.56	0.022	−0.05	0.855	0.53	0.036
Temporal inner macula	−0.09	0.747	0.26	0.316	0.04	0.891	0.32	0.230	−0.25	0.341	0.46	0.070
Temporal outer macula	−0.08	0.757	0.43	0.093	−0.27	0.308	0.37	0.163	−0.31	0.244	0.43	0.096

Abbreviations: ERG, electroretinogram; Rc, standard partial regression coefficient.

Table 6 Correlations between ERG parameters and the nonperfused area of the retina

	ρ	P-value
Cone a-wave
Amplitude (μV)	−0.28	0.287
Implicit time (ms)	0.28	0.290
Cone b-wave
Amplitude (μV)	−0.41	0.115
Implicit time (ms)	0.62	0.011
Flicker wave
Amplitude (μV)	−0.25	0.350
Implicit time (ms)	0.54	0.031

Abbreviations: ERG, electroretinogram; ρ, correlation coefficient.