A recent study has identified a novel retinal condition, termed hyperacute outer retinal dysfunction, which affects pediatric patients following febrile illness. In a multicenter case series, researchers investigated the clinical characteristics, retinal imaging findings, and prognosis of children who presented with sudden, severe bilateral vision loss accompanied by diffuse disruptions in the ellipsoid zone and external limiting membrane.

Yizhe Cheng, MD, of the Guangdong Provincial Clinical Research Center for Ocular Diseases in Guangzhou, China, and colleagues analyzed 8 pediatric patients (6 boys and 2 girls; 16 eyes) from north and south regions of China who experienced acute bilateral vision loss following febrile illness.

Patients were evaluated between November 2022 and May 2023; their symptoms included nyctalopia, visual field constriction, and color vision abnormalities, as well as difficulty descending stairs and otherwise walking independently. All patients underwent comprehensive ophthalmic evaluations, including multimodal imaging, electroretinography (ERG), and systemic laboratory testing, to exclude other potential etiologies, as detailed in the researchers’ recent JAMA Ophthalmology article.

Patients were a mean age of 5.1 years of age. Vision loss occurred an average of 16.1 days after fever onset. At presentation, best-corrected visual acuity (BCVA) was at counting fingers or worse for most patients. All 16 eyes showed diffuse ellipsoid zone (EZ) and external limiting membrane (ELM) loss.

Macular recovery began around week 4. At 1-year follow-up, 7 of 8 patients (88%) had BCVA of 20/40 or better, and 4 patients (50%) achieved 20/25 or better.

Initial optical coherence tomography (OCT) revealed early-stage intraretinal hyperreflective dots, peripheral vascular sheathing, and diffuse outer retinal layer disruption. Over time, the macular EZ and ELM showed partial recovery, though the extrafoveal regions remained deficient.

ERG revealed extinguished rod and cone responses in all patients at the time of diagnosis; multifocal ERG remained absent despite visual acuity improvements. Laboratory workups did not indicate infectious causes, but elevated inflammatory markers were observed in some cases.

All patients were treated with corticosteroids (intravenous or oral). Two patients were treated with immunosuppressive therapies (ie, cyclosporine A or methotrexate), while 7 patients were given intravenous immunoglobulin. Treatment was initiated at symptom onset in 3 patients, 1 week after onset in 2 patients, and 2 to 3 weeks after onset for the remaining 6 patients. However, their efficacy remains unclear because treatment strategies were inconsistent and there was no control group.

This study suggests that hyperacute outer retinal dysfunction (HORD) is a distinct clinical entity that primarily affects young children after fever. The condition presents with acute, severe vision loss but demonstrates notable recovery of central vision in most cases, unlike non-paraneoplastic autoimmune retinopathy (np-AIR), which was originally in the differential diagnosis.

The investigators also considered retinitis pigmentosa (RP). “However,” they wrote, “HORD differs from RP because of its hyperacute onset, identifiable triggers, and lack of genetic background typically associated with RP. These distinctions suggest that HORD is not a subtype of RP. Understanding whether these patients will eventually recover, stabilize, or worsen requires careful long-term follow-up and is a key question for future investigation.”