Electroretinogram abnormalities in non‐infectious uveitis often persist

PURPOSE: In uveitis, a prolonged implicit time of the cone b‐wave is a characteristic electroretinogram (ERG) abnormality. We investigated whether this can improve or deteriorate over time and which clinical factors are associated with change. METHODS: Prospective cohort study. Patients with a non‐infectious uveitis were included. An ERG was measured in the first year of uveitis onset and a follow‐up ERG one year later. Changes in the implicit time of the cone b‐wave were investigated in relation to clinical parameters including the following: demographics, uveitis characteristics, treatment, best‐corrected visual acuity, optical coherence tomography parameters and fluorescein angiography scores. RESULTS: Of 98 eyes (63 patients), 40 showed a prolonged cone b‐wave on the first ERG, which improved in 10 eyes. Eyes with an improved ERG more often had a panuveitis with initially a higher incidence of cells in the anterior chamber during the first ERG, which resolved at the time of their follow‐up ERG. Five of the 58 eyes with a normal first ERG had a deteriorated follow‐up ERG. These eyes had more frequently an active uveitis at the time of the follow‐up ERG. Of the 78 eyes with a stable cone b‐wave, 16 had a quiescent inflammation during follow‐up. There were no differences in age or treatment. CONCLUSION: In most patients with non‐infectious uveitis, ERG abnormalities appear to be irreversible, even when the inflammation becomes quiescent. However, some ERGs improved, which was associated with reduction in inflammation of the anterior chamber due to panuveitis. In contrast, a worsened ERG was associated with a persistence of inflammation.