Flash Electroretinography as a Measure of Retinal Function in Myopia and Hyperopia: A Systematic Review

Zahra, Sania; Murphy, Melanie; Riddell, Nina

doi:10.3390/vision7010015

Cited by 4 publications

(4 citation statements)

References 59 publications

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“…Results from studies assessing retinal function in myopes using electroretinograms (ERGs) are mixed, but most point to an attenuation of the a-wave (cone and OFF-bipolar cells 15 ) and b-wave amplitudes (ON- and OFF-cone bipolar cells 16 , 17 ) with no changes in their implicit times. 18 , 19 This finding is also supported by evidence from genetic studies. 20 , 21 …”

Section: Introductionsupporting

confidence: 69%

Early Alterations in Inner-Retina Neural and Glial Saturated Responses in Lens-Induced Myopia

Ablordeppey,

Nieu,

Lin

et al. 2024

Trans. Vis. Sci. Tech.

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Purpose Myopic marmosets are known to exhibit significant inner retinal thinning compared to age-matched controls. The purpose of this study was to assess inner retinal activity in marmosets with lens-induced myopia compared to age-matched controls and evaluate its relationship with induced changes in refractive state and eye growth. Methods Cycloplegic refractive error (Rx), vitreous chamber depth (VCD), and photopic full-field electroretinogram were measured in 14 marmosets treated binocularly with negative contact lenses compared to 9 untreated controls at different stages throughout the experimental period (from 74 to 369 days of age). The implicit times of the a-, b-, d-, and photopic negative response (PhNR) waves, as well as the saturated amplitude ( V max ), semi-saturation constant (K), and slope (n) estimated from intensity-response functions fitted with Naka-Rushton equations were analyzed. Results Compared to controls, treated marmosets exhibited attenuated b-, d-, and PhNR waves V max amplitudes 7 to 14 days into treatment before compensatory changes in refraction and eye growth occurred. At later time points, when treated marmosets had developed axial myopia, the amplitudes and implicit times of the b-, d-, and PhNR waves were similar between groups. In controls, the PhNR wave saturated amplitude increased as the b + d-wave V max increased. This trend was absent in treated marmosets. Conclusions Marmosets induced with negative defocus exhibit early alterations in inner retinal saturated amplitudes compared to controls, prior to the development of compensatory myopia. These early ERG changes are independent of refraction and eye size and may reflect early changes in bipolar, ganglion, amacrine, or glial cell physiology prior to myopia development. Translational Relevance The early changes in retinal function identified in the negative lens-treated marmosets may serve as clinical biomarkers to help identify children at risk of developing myopia.

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Section: Introductionsupporting

confidence: 69%

Early Alterations in Inner-Retina Neural and Glial Saturated Responses in Lens-Induced Myopia

Ablordeppey,

Nieu,

Lin

et al. 2024

Trans. Vis. Sci. Tech.

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“…The amplitude of the a-wave is proportional to the number of functioning photoreceptor cells in the retina as well as to their sensitivity to light. In addition, we also observed a decrease in the amplitude of the scotopic b-wave, which reflects the function of bipolar cells in the retina [41]. The loss of photoreceptor cells can also lead to a reduction in the amplitude of the scotopic b-wave in ERG recordings, reflecting the function of bipolar cells in the retina, suggesting a loss of bipolar cell function during AMD.…”

Section: Discussionsupporting

confidence: 50%

Prevention of Inflammation, Neovascularization, and Retinal Dysfunction by Kinin B1 Receptor Antagonism in a Mouse Model of Age-Related Macular Degeneration

Bhat,

Shirzad,

Fofana

et al. 2023

JCM

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The kallikrein-kinin system (KKS) contributes to vascular inflammation and neovascularization in age-related macular degeneration (AMD), particularly via the kinin B1 receptor (B1R). The aim of the present study was to determine the protective effects of the topical administration of the B1R antagonist (R-954) on inflammation, neovascularization, and retinal dysfunction in a murine model of neovascular AMD. Choroidal neovascularization (CNV) was induced in C57BL6 mice using an argon laser. A treatment with ocular drops of R-954 (100 μg/15 μL, twice daily in both eyes), or vehicle, was started immediately on day 0, for 7, 14, or 21 days. CNV, invasive microglia, and B1R immunoreactive glial cells, as well as electroretinography alterations, were observed within the retina and choroid of the CNV group but not in the control group. The staining of B1R was abolished by R-954 treatment as well as the proliferation of microglia. R-954 treatment prevented the CNV development (volume: 20 ± 2 vs. 152 ± 5 × 104 µm3 in R-954 vs. saline treatment). R-954 also significantly decreased photoreceptor and bipolar cell dysfunction (a-wave amplitude: −47 ± 20 vs. −34 ± 14 µV and b-wave amplitude: 101 ± 27 vs. 64 ± 17 µV in R-954 vs. saline treatment, day 7) as well as angiogenesis tufts in the retina. These results suggest that self-administration of R-954 by eye-drop treatment could be a promising therapy in AMD to preserve retinal health and vision.

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“…While the effect of myopia on outer retina function is mixed, the preponderance of the evidence in human and animal studies report decreased photopic a-wave amplitudes with no effect on implicit time in physiological myopia. 79 , 80 A possible explanation may be the direct effect of myopia on photoreceptors, suggesting that myopic growth results in phototransduction and mitochondrial metabolic dysfunction, 81 and substantial deleterious changes to photoreceptor morphology. 82 It could also be argued that changes in electrical resistance may explain the differences observed in the a-wave amplitude.…”

Section: Discussionmentioning

confidence: 99%

Choroidal Morphology and Photoreceptor Activity Are Related and Affected by Myopia Development

Ablordeppey,

Lin,

Song

et al. 2024

Invest. Ophthalmol. Vis. Sci.

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Purpose The choroid is critical for the regulation of eye growth and is involved in the pathogenesis of myopia-associated ocular complications. This study explores the relationship among choroidal biometry, photoreceptor activity, and myopic growth in marmosets ( Callithrix jacchus ) with lens-induced myopia. Methods A total of 34 common marmosets aged 92 to 273 days old were included in this study. Axial myopia was induced in 17 marmosets using negative soft contact lenses and 17 marmosets served as untreated controls. Cycloplegic refraction (RE) and vitreous chamber depth (VCD) were measured using autorefraction and A-scan ultrasonography, respectively. Choroidal scans were obtained using spectral-domain optical coherence tomography and binarized to calculate subfoveal choroidal thickness (ChT), total choroidal area (TCA), luminal area (LA), stromal area (SA), choroidal vascularity index (CVI), and LA/SA. To assess photoreceptor activity, the a-wave of the full-field electroretinogram was measured. Regression models were used to investigate the relationship between outcome measures. Results Eyes induced with axial myopia (RE = −7.14 ± 4.03 diopters [D], VCD = 6.86 ± 0.39 mm) showed significant reductions (4.92–21.24%) in all choroidal parameters (ChT, TCA, LA, SA, CVI, and LA/SA) compared to controls (RE = −1.25 ± 0.60 D, VCD = 6.58 ± 0.26 mm, all P < 0.05), which changed as a function of refraction and vitreous elongation, and were associated with a decrease in the a-wave amplitude. Further, multiple regression showed that a combination of ChT and CVI could well predict RE and VCD. Conclusions This study reports the existence of significant alterations in choroidal morphology in non-human primate eyes induced with myopia. The changes in choroidal anatomy were associated with reduced light-adapted a-wave amplitude. These findings may represent early markers for reduced visual performance and chorioretinal complications known to occur in eyes with large degrees of myopia.

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Flash Electroretinography as a Measure of Retinal Function in Myopia and Hyperopia: A Systematic Review

Cited by 4 publications

References 59 publications

Early Alterations in Inner-Retina Neural and Glial Saturated Responses in Lens-Induced Myopia

Early Alterations in Inner-Retina Neural and Glial Saturated Responses in Lens-Induced Myopia

Prevention of Inflammation, Neovascularization, and Retinal Dysfunction by Kinin B1 Receptor Antagonism in a Mouse Model of Age-Related Macular Degeneration

Choroidal Morphology and Photoreceptor Activity Are Related and Affected by Myopia Development

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