Electroretinographic evaluation of single vision contact lenses with non-refractive opaque features

Clinical relevance: Electroretinography provides insights into how optical interventions, e.g., contact lenses (CLs), may influence retinal function. Understanding acute retinal responses is important for the ongoing development of myopia control strategies.

Background: To investigate the acute effects of single-vision (test) soft CLs incorporating non-refractive opaque elements on retinal function. These lenses are designed to modulate retinal ganglion cell activity through Active Reconfiguration in Retinal Encoding of Spatio-Temporal signalling with a potential for myopia control.

Methods: In a randomised, contralateral-eye study, 30 participants (18 to 25 years; refractive error: 0.00D to -5.50D) wore single-vision test and control CLs. Electroretinograms were recorded at baseline, 10, and 40 minutes using red flash stimuli (38 Troland-seconds at 3.8 Hz) on a blue background (380 Trolands). Time-amplitude and Discrete Wavelet Transform analyses quantified changes in retinal response. Metrics included a-wave and b-wave peak times and amplitudes, Photopic Negative Response (PhNR) amplitude and timing, P-ratio, W-ratio, and OFF/ON pathway coefficients.

Results: TTest lenses induced significant delays in a-wave (mean difference [MD]: 0.26 ms, p = 0.008) and b-wave (MD: 0.26 ms, p < 0.001) peak times, with no significant amplitude changes. PhNR amplitude was significantly reduced (MD: 0.42 µV, p = 0.01), and peak time was delayed (MD: 0.51 ms, p = 0.02). P ratio (MD: –0.04, p = 0.001), and W-ratio (MD: –0.04, p = 0.004) significantly suppressed with test lenses. Time-frequency analysis revealed selective suppression of OFF-pathway activity (40Hz coefficient, MD: –0.89 µV-s, p = 0.02) with test lenses, while ON-pathway components remained stable. 80Hz oscillatory potentials were significantly reduced with test lenses (MD: –1.35 µV-s, p = 0.02).   

Conclusion: Non-refractive opaque features within an otherwise single-vision CL can induce short-term changes in retinal signalling, characterised by temporal shifts in post-receptoral signalling, potentially suggesting pathway-specific modulation of inner retinal circuits. Additional studies are needed to confirm the preliminary findings to facilitate insights into the retinal mechanism of action with such interventions.