The clinical relevance of hyper-reflective foci in the inner retina at the diagnosis of multiple sclerosis

Background: Hyper-Reflective foci (HRF) increased in the inner retina (IR) of patients with Multiple Sclerosis (pwMS). Objective: To evaluate the risk of therapeutic failure, based on HRF count at baseline. Methods: Fifty-seven pwMS were included in this retrospective, cohort, single-centre study. All patients were enrolled at clinical onset and were treatment-naive, with no evidence of optic nerve involvement. Patient were divided at baseline based on the MS treatment in platform-therapy pwMS (PTpwMS) and as High efficacy therapy pwMS (HETpwMS). Then, all PTpwMS were followed up (87.6±31.2 months) to evaluate the time to therapeutic switch for lack of efficacy on outcomes. HRF count was expressed as the sum of both eyes in Ganglion Cell-Inner Plexiform Layer (GCIP), Inner Nuclear Layer (INL) and Inner Retina (IR, GCIP + INL). Results: Survival analysis confirmed an increased risk of therapeutic switch in those patients with a higher HRF-INL count (Log-Rank p < 0.0001, H.R. 7.9, 95%CI 2.6-24.5). PTpwMS switching during the follow up had significantly higher HRF count in INL compared to not-switching (45.80 ± 10.32vs 31.75 ± 6.27, p < 0.05). Conclusions: HRF might be a useful marker to predict the risk of acute demyelination in MS and might give help Neurologist in therapeutic decision.