Multifocal Electroretinogram in Adults and Children With Myopia

Abstract

Objective: To determine the correlation between multifocal electroretinogram (mfERG) parameters and the severity of myopia in adults and children. Design: Observational study. Methods: Multifocal electroretinograms were recorded using the VERIS system from randomly selected eyes of 104 children and 31 adults with various degrees of myopia. Dawson, Trick, and Litzkow fiber electrodes were used and the pupil was dilated with 1% tropicamide. Subjective refraction was performed under cycloplegia and axial length measurement was determined by A-scan ultrasonography. The N1 (first negative trough), P1 (first positive peak), and N2 (second negative trough) components of the first-order kernel response of the mfERG were measured and correlated with the refractive data. Main Outcome Measures: First-order kernel mfERG responses. Results: The N1, P1, and N2 amplitudes were significantly correlated with the severity of myopia in adult subjects (N1, r=0.591, P =.001; P1, r=0.682, PϽ.001; N2, r=0.732, PϽ.001). The response amplitudes of N1, P1, and N2 decreased as the dioptric power of myopia increased. However, there were no significant correlations found between N1 (r=0.073, P=.30), P1 (r=0.071, P=.31), and N2 (r=0.052, P=.46) amplitudes and the severity of myopia in children. The severity of myopia was also significantly correlated with N1 (r=−0.750, PϽ.001), P1 (r=−0.769, PϽ.001), and N2 (r=−0.664, PϽ.001) implicit times in adults with myopia, however, only the P1 (r =−0.166, P =.02) implicit time was significantly correlated with children with myopia. Conclusions: There is a significant correlation between the refractive error and mfERG amplitude in adults with myopia; however, such a relationship is absent in children with myopia. These findings suggest that the severity of myopia has little influence on the ERG amplitude, at least in children.

Subclinical Decrease in Central Inner Retinal Activity Is Associated With Myopia Development in Children

“…2,8,9,18,19 Researchers have suggested that the reduced ERG amplitude could result from an increase in the subretinal space, 20 reduced image size, decreased retinal illumination, and the reduced retinal cell density 9,21 in the elongated eyeball. However, none of these factors could explain the findings in children.…”

“…Application of the ERG technique has provided ample evidence to confirm that myopia results in impaired retinal function. It has been reported that myopia in adults was associated with decreased nonlinear components of ERG responses, 1 multifocal ERG (mfERG) responses, 2,3 retinal adaptation response, 4 and inner retinal function. [5][6][7] Axial length was shown to be linearly related to ERG amplitudes, 8 first-order kernel, and the first slice of second-order kernel of mfERG responses.…”

“…However, this explanation cannot be applied to myopic children, and discrepancies of ERG characteristics have been noted between myopic adults and children. 2,7 Luu and his colleagues 2 conducted a cross-sectional study of mfERG measurement in 104 children and 31 adults with a range of refractive errors. They found a significant correlation between refractive error and mfERG response in adults, but this correlation was not observed in children.…”

Influence of Macular Choroidal Thickness on Visual Function in Highly Myopic Eyes

“…This finding could be partially explained mechanistically by a change in the ocular structure due to increased AL in myopic eyes that determines an increased stretching of the macular area causing a coarser distribution of cones in the posterior retina [26]. Electroretinogram testing, including multifocal electroretinography, has shown decreased b-wave amplitudes with increased AL in eyes affected by nonpathological myopia, which indicates early injury of the cones [27,28,29,30]. …”

Multifocal Electroretinography in HIV-Positive Patients without Infectious Retinitis

“…Multifocal ERG has been used to localize focal retinal damage occurring in numerous diseases and disorders 20,21,22,23,24,25,26,27 and has been proven to be a reliable diagnostic tool in clinical settings. Mulifocal ERG can measure the function of the outer retina as well as the inner retina.…”