Multimodal imaging of ASHH in a case of Scrub Typhus Retinopathy

PURPOSE: To report a case of scrub typhus retinopathy presenting with angular sign of Henle layer hyperreflectivity (ASHH) on optical coherence tomography (OCT). METHODS: This is a retrospective case report with multimodal imaging. RESULTS: A 43-year-old Indian man presented with sudden, painless diminution of vision in both eyes,(left more than right) following a febrile illness. He was diagnosed with scrub typhus based on positive IgM ELISA. Fundus examination revealed scattered intraretinal haemorrhages in both eyes and a yellowish foveal lesion in the left eye. Optical coherence tomography (OCT) demonstrated angular sign of Henle layer hyperreflectivity (ASHH) in both eyes, with a hard exudate clump at the fovea in the left eye and corresponding areas of blocked fluorescence on fluorescein angiography. A diagnosis of scrub typhus retinopathy was made. After treatment with oral corticosteroids, at one-month follow-up, visual acuity, with marked resolution of haemorrhages and regression of ASHH on OCT. CONCLUSION: Scrub typhus can present with retinopathy associated with ASHH, a marker of deep retinal ischemia. Multimodal imaging, particularly OCT, plays a crucial role in identifying ischemic retinal changes and may help in assessing disease severity and visual prognosis.