A Case Series of Angular Sign of Henle Fiber Layer Hyperreflectivity (ASHH): A Novel Optical Coherence Tomography (OCT) Biomarker

The angular sign of Henle fiber layer (HFL) hyperreflectivity (ASHH) is a newly described optical coherence tomography (OCT) biomarker of acute macular photoreceptor injury. It appears on OCT as a hyperreflective band along the oblique HFL, extending from the outer plexiform layer (OPL) to the ellipsoid zone (EZ). ASHH occurs in macular disorders of ischemic, inflammatory, or mechanical/traumatic origin. This case series describes three patients with ASHH in distinct conditions and discusses its clinical relevance. A 24-year-old man with acute posterior multifocal placoid pigment epitheliopathy (APMPPE) presented with acute bilateral painless central vision loss and placoid macular lesions after a respiratory infection. OCT showed an ASHH indicative of photoreceptor disruption. A 28-year-old man sustained blunt ocular trauma from an ice projectile with commotio retinae. Early OCT revealed an ASHH in the macula, indicating acute photoreceptor axon injury. An 11-year-old boy sustained blunt ocular trauma from a thrown stone, causing a choroidal rupture. Acute OCT presented an ASHH, highlighting severe outer retinal damage. ASHH was identified in all three cases at presentation and co-localized with clinically affected macular regions. Serial OCT demonstrated reduction of hyperreflectivity over time in each case, with variable structural sequelae and favorable prognosis for the ultimate visual acuity. Across cases, documenting ASHH improved clinic-imaging correlation and provided a reproducible anchor for monitoring recovery. The HFL may be disrupted in various inflammatory, ischemic, and traumatic retinal conditions. In APMPPE, inner choroidal ischemia and inflammation lead to photoreceptor injury. In contusion injuries, force transmission causes photoreceptor axonal swelling and HFL disruption. ASHH typically resolves over weeks, often leaving outer retinal thinning or retinal pigmented epithelium changes with some visual sequelae. Recognizing ASHH as an OCT biomarker across diverse conditions may guide diagnostic procedures and therapeutic interventions.