Steady-State Pattern Electroretinogram and Frequency Doubling Technology in Adult Dyslexic Readers

Figures & data

Table 1 Best Corrected Visual Acuity (BCVA) Values (Mean Values and Standard Deviation) and Diopter Spherical Equivalent (SE) Values (Mean Values and Standard Deviation)

	Control Group	Dyslexic Group	p-value
Men: Women	4:6	3:7	0.765
Age (yrs) CI 95%	27.8 ± 3.3 25.4/30.2	28.5 ± 3.9 25.6/31.3	0.431
BVCA (decimal)	1.0 ± 0.03	1.0 ± 0.04	0.980
SE (diopter)	− 0.3 ± 1.3	− 0.5 ± 1.4	0.312

Abbreviation: CI, confidence interval.

Table 2 Steady-State Pattern Electroretinogram (SS-PERG) Amplitude Values (Mean Values and Standard Deviation)

	Control Group	Dyslexic Group	p-value
SS-PERG (μV)	1.250 ± 0.296	0.610 ± 0.110	0.0001
CI 95%	1.111/1.389	0.559/0.661

Abbreviation: CI, confidence interval.

Table 3 Steady-State Pattern Electroretinogram (SS-PERG) Amplitude Values of the Right Eye (RE) and Left eye (LE) in Dyslexics and Control Subjects

	Dyslexic RE	Dyslexic LE	p-value	Control RE	Control LE	p-value
SS-PERG (μV)	0.671 ± 0.11	0.559 ± 0.15	0.001	1.29 ± 0.31	1.34 ± 0.32	0.596
CI 95%	0.595/0.747	0.490/0.628		1.01/1.51	1.12/1.57

Abbreviation: CI, confidence interval.

Figure 1 Steady-state pattern electroretinogram waveforms recorded in the right and left eye of control normal subject (top) and dyslexic subject (bottom). It can be observed a reduction of waveform amplitude in both eyes of the dyslexic subject (bottom) against the normal subject (top). Moreover, the dyslexics have a waveform amplitude decrease in the LE compared to the RE while in the normal subjects we have a slight increase in waveform amplitude in the LE than in the RE.

Abbreviations: RE, right eye; LE, left eye.

Table 4 Frequency Doubling Technology (FDT) Perimetry Values (Mean Values and Standard Deviation)

	Control Group	Dyslexic Group	p-value
FDT-MD (dB)	− 0.81 ± 0.61	− 2.28 ± 1.19	0.056
CI 95%	− 1.09/ - 0.52	−2.84/-1.72
FDT-PSD (dB)	2.99 ± 0.35	4.40 ± 0.81	0.0001
CI 95%	2.79/3.17	4.10/4.78

Abbreviation: MD, mean deviation; PSD, pattern standard deviation; CI, confidence interval.

Table 5 Frequency Doubling Technology (FDT) Index Values of the Right Eye (RE) and Left eye (LE) in Dyslexics and Control Subjects

	Dyslexic RE	Dyslexic LE	p-value	Control RE	Control LE	p-value
FDT-PSD (dB)	3.66 ± 0.96	4.43 ± 1.10	0.031	2.99 ± 0.42	2.95 ± 0.40	0.791
CI 95%	2.97/4.35	3.65/5.22		2.69/3.3	2.66/3.23

Abbreviations: PSD, pattern standard deviation; CI, confidence interval.

Table 6 Intragroup Steady-State Pattern Electroretinogram (SS-PERG) and Frequency Doubling Technology (FDT) Perimetry Index Values of the Right Eye (RE) and Left eye (LE) in Dyslexic Subjects and Control Subjects

	Dyslexic RE	Control RE	p-value	Dyslexic LE	Control LE	p-value
SS-PERG (μV)	0.671 ± 0.11	1.29 ± 0.31	0.0003	0.559 ± 0.15	1.34 ± 0.32	0.0001
CI 95%	0.595/0.747	1.01/1.51		0.490/0.628	1.12/1.57
FDT-PSD (dB)	3.66 ± 0.96	2.99 ± 0.42	0.0002	4.43 ± 1.10	2.95 ± 0.40	0.0002
CI 95%	2.97/4.35	2.69/3.3		3.65/5.22	2.66/3.23

Abbreviations: PSD, pattern standard deviation; CI, confidence interval.

Table 7 Spearman’s Correlation Test Between Steady-State Pattern Electroretinogram (SS-PERG) and Frequency Doubling Technology (FDT) Index Values in the Right Eye (RE) and in the Left Eye (LE) of Dyslexic Subjects and of Control Subjects

	SS-PERG (μV)	FDT-PSD (dB)	r	p-value
Dyslexic (both eyes)	0.610 ± 0.11	4.40 ± 0.81	0.80	0.001
Dyslexic LE	0.559 ± 0.15	4.43 ± 1.10	0.93	0.001
Dyslexic RE	0.671 ± 0.11	3.66 ± 0.96	0.81	0.005
Control (both eyes)	1.250 ± 0.296	2.99 ± 0.35	0.56	0.011
Control RE	1.29 ± 0.31	2.99 ± 0.42	0.78	0.008
Control LE	1.34 ± 0.32	2.95 ± 0.40	0.68	0.032

Abbreviation: PSD, pattern standard deviation.

Figure 2 Scatterplot of Spearman’s correlation test between steady-state pattern electroretinogram (SS-PERG) and frequency doubling technology (FDT) in the dyslexic group.

Abbreviation: PSD, pattern standard deviation.

Figure 3 Scatterplot of Spearman’s correlation test between steady-state pattern electroretinogram (SS-PERG) and frequency doubling technology (FDT) in the left eye of the dyslexic group.

Abbreviation: PSD, pattern standard deviation.

Figure 4 Scatterplot of Spearman’s correlation test between steady-state pattern electroretinogram (SS-PERG) and frequency doubling technology (FDT) in the right eye of dyslexic group.

Abbreviation: PSD, pattern standard deviation.