Repeatability of photopic negative response parameters in normal subjects using Diopsys®NOVA™

Abstract

Purpose : Photopic negative response (PhNR) has been utilized to evaluate the optic nerve and ganglion cell layer function. However, the general application is limited due to the complexity and long duration of the standard protocol using traditional electroretinography devices. Diopsys®NOVA™ is a new user-friendly electroretinography device which is capable of measuring PhNR parameters more rapidly. In this prospective case series, we evaluated the repeatability of PhNR measurements in normal subjects (no known ocular disease).

Methods : A total of 36 eyes of 18 healthy subjects were included in the study. PhNR and its related parameters, including MVAIndex (an AI-assisted index devised by the device company to predict the abnormality of PhNR), latency (for PhNR, A-wave, and B-wave), and amplitude (for PhNR, A-wave, and B-wave) were measured using Diopsys®NOVA™. The measurements were performed 3 consecutive times, with 10-minute intervals, during the same session by a single examiner. The statistical test of repeatability [intraclass correlation coefficient (ICC)], was calculated using R (version 4.1.3).

Results : The mean age of the subjects was 30.94 ± 4.59 years old. MVAIndex and PhNR latency showed good-to-excellent repeatability [0.614-0.853 (p < 0.0001)], [0.397-0.741 (p < 0.0001)], respectively; however, PhNR amplitude values demonstrated poor repeatability [-0.065-0.353 (p = 0.105)]. Using the ICC, A and B waves latencies had excellent repeatabilities [0.624-0.858 (p < 0.0001); 0.798-0.930 (p < 0.0001)]. A-wave and B-wave amplitude had good-to-excellent [0.413-0.748 (p < 0.0001)] and excellent [0.677-0.883 (p < 0.0001)] repeatability, respectively.

Conclusions : The majority of PhNR and its related parameters measurements using Diopsys®NOVA™ in subjects with no known ocular disease showed a good-to-excellent level of repeatability. Based on this finding, Diopsys®NOVA™ may be considered as an alternative and rapid method for measuring the PhNR parameters.

This abstract was presented at the 2023 ARVO Annual Meeting, held in New Orleans, LA, April 23-27, 2023.