Steady-State Pattern Electroretinogram and Frequency Doubling Technology in Adult Dyslexic Readers
Authors Schiavi C, Finzi A, Cellini M
Received 14 September 2019
Accepted for publication 27 November 2019
Published 11 December 2019 Volume 2019:13 Pages 2451—2459
Checked for plagiarism Yes
Review by Single anonymous peer review
Peer reviewer comments 2
Editor who approved publication: Dr Scott Fraser
Costantino Schiavi, Alessandro Finzi, Mauro Cellini
Department of Experimental, Diagnostic, and Specialty Medicine, Ophthalmology Service, University of Bologna, Bologna 40138, Italy
Correspondence: Mauro Cellini
Policlinico Sant’Orsola-Malpighi, Ophthalmology Service, University of Bologna, Via Pelagio Palagi 9, Bologna 40138, Italy
Tel/Fax +39 0516362835
Purpose: Dyslexia is a reading disorder with neurological deficit of the magnocellular pathway. The aim of our study was to evaluate the functionality of the magnocellular–Y (M–Y) retinal ganglion cells in adult dyslexic subjects using steady-state pattern electroretinogram and frequency doubling perimetry.
Methods: Ten patients with dyslexia (7 females and 3 males), mean age 28.7 ± 5.9 years, and 10 subjects without dyslexia (6 females and 4 males), mean age 27.8 ± 4.1 years, were enrolled in the study and underwent both steady-state pattern-electroretinogram examination and frequency doubling perimetry.
Results: There was a significant difference in the amplitude of the steady-state pattern electroretinogram of the dyslexic group and the healthy controls (0.610±0.110 μV vs 1.250±0.296 μV; p=0.0001). Furthermore, in the dyslexic group we found a significant difference between the right eye and the left eye (0.671±0.11 μV vs 0.559±0.15 μV; p=0.001). With frequency doubling perimetry, the pattern standard deviation index increased in dyslexic eyes compared to healthy controls (4.40±0.81 dB vs 2.99±0.35 dB; p=0.0001) and in the left eye versus the right eye of the dyslexic group (4.43±1.10 dB vs 3.66±0.96 dB; p=0.031). There was a correlation between the reduction in the wave amplitude of the pattern electroretinogram and the simultaneous increase in the pattern standard deviation values (r=0.80; p=0.001). This correlation was also found to be present in the left eye (r=0.93; p<0.001) and the right eye (r=0.81; p=0.005) of dyslexic subjects.
Conclusion: Our study shows that there was an alteration of the activity of M–Y retinal ganglion cells, especially in the left eye. It confirms that in dyslexia there is a deficit of visual attention with damage not only of the magnocellular-dorsal pathway but also of the M-Y retinal ganglion cells.
Keywords: steady-state pattern-electroretinogram, frequency doubling technology perimetry, retino-geniculate pathways, dyslexia