The association between multifocal electroretinograms and OCT retinal thickness in retinitis pigmentosa patients with good visual acuity

Abstract

Aims To investigate relationships between retinal morphology and retinal function in patients with retinitis pigmentosa (RP) using optical coherence tomography (OCT) and multifocal electroretinography (mfERG). Methods In all, 14 patients with RP who had visual acuities of 0.2 logMAR or better and Humphrey central fields of 101 or larger participated in the study along with 16 normal control subjects. The amplitudes and timings of the mfERG responses were compared with spatially corresponding measures of retinal layer thickness from OCT within the macula region (central 121). Results Eyes with RP showed thinning of the photoreceptor retinal (PR) layer and thickening of mid-inner retinal (MIR) layers beyond the fovea. mfERG amplitude was reduced in all regions, whereas mfERG timing was only significantly delayed at a retinal eccentricity of 6-121 and was otherwise preserved within the foveal and parafoveal retina (0-61). PR layer thickness was correlated with mfERG amplitude across the macula region. mfERG timing was correlated with the total change in retinal thickness (combined PR thinning and MIR thickening) at an eccentricity of 6-121. Conclusions The relationship between mfERG timing and retinal thickness in RP is dependent on the retinal eccentricity. Preserved timing in the central retina (0-61), despite significant disruption to retinal laminar structure, could be suggestive of inner retinal remodelling or functional redundancy.Cone system activity derived from mfERG amplitude appears to be related to the thickness of the photoreceptor layer in the macula region.

Cone dysfunctions in retinitis pigmentosa with retinal nerve fiber layer thickening

“…Sugita et al in a focal macular ERG study stated that preserved macular morphology does not necessarily guarantee reserved electrical potential in RP patients 12. In a multifocal ERG study, Wolsley et al reported that preserved timing in the central retina, despite significant disruption of the retinal laminar structure, could be suggestive of inner retinal remodeling or functional redundancy 13. They also stated that cone-system activity shown in multifocal ERG responses could be related to the thickness of the photoreceptor layer in the macular region.…”

Optical Coherence Tomographic Analysis of Retina in Retinitis Pigmentosa Patients

“…While the mfERG amplitude was preserved within the area of 0-6°, the photoreceptor segments were relatively intact [33]. The patients with longer EZ lines had significantly larger mfERG amplitudes than the patients with shorter or absent EZ lines [27].…”

Effects of luminance combinations on the characteristics of the global flash multifocal electroretinogram (mfERG)

“…It helps in examining local functional losses in various retinal diseases such as glaucoma, diabetic retinopathy, agerelated macular degeneration and retinitis pigmentosa [1][2][3][4][5][6][7][8][9][10][11]. The conventional mfERG signals were reported to mainly originate from bipolar cells [12,13].…”