Rod system impairment is connected with ON-pathway deficiencies. As a result, the ON pathway function may serve as a proxy marker for the rod system. For a study, researchers employed an iOS tablet application named ‘EyeSpeed’ to measure the ON and OFF pathway impairments in individuals with known retinal disorders. The research included 26 individuals (19 men and 7 women). Based on fundus findings, history, and/or electroretinographic results, the patients were classified as having rod-dominated illness [n=14; retinitis pigmentosa (12), rod monochromatism (2)] or cone-dominated disease [n=12; Stargardt’s disease (5) or cone dystrophy (7)]. The participants ranged in age from 10 to 46 years. The inclusion criteria were N24 or more excellent near vision and the absence of any other ocular illness. The aim for the participants is to identify the number of black/white targets contained in a noisy binary backdrop. Outcome variables were outcome variables: reaction time, accuracy, and performance index [accuracy*(1/reaction time)] were outcome variables. 

The mean difference in reaction times (dark – light) for rod-dominated disease was substantially larger than for cone-dominated disease [[-0.65s (0.23)]; unpaired t-test, P=0.019]. However, the mean variations in accuracy and performance index between dark and bright targets were not substantially different between the two groups. When compared to OFF-pathway deficiencies, ON pathway deficits were more evident in rod-dominated illness.

Reference:jov.arvojournals.org/article.aspx?articleid=2778481