Henle fibre layer haemorrhage: clinical features and pathogenesis

Area of Science:

• Ophthalmology
• Retinal Imaging
• Vascular Biology

Background:

• Deep retinal hemorrhages in the macula, specifically in the Henle fiber layer (HFL), present unique clinical and imaging characteristics.
• Understanding the diverse etiologies and pathogenesis of these hemorrhages is crucial for diagnosis and management.

Purpose of the Study:

• To describe the clinical presentation and characteristic imaging features of deep retinal hemorrhages located in the Henle fiber layer (HFL) of the macula.
• To present the spectrum of etiologies and a comprehensive theory of pathogenesis for these specific retinal hemorrhages.

Main Methods:

• Retrospective, multicenter case series evaluating eyes with retinal hemorrhages in the HFL.
• Utilized multimodal imaging, including fundus photography and optical coherence tomography (OCT) for cross-sectional and en face views.
• Collected data on clinical features, etiology, risk factors, and visual acuity.

Main Results:

• Thirty-three eyes from 23 patients exhibited HFL hemorrhages secondary to various causes including trauma, Terson's syndrome, anesthesia, hypertension, decompression retinopathy, postvitrectomy, retinal vein occlusion, myopic degeneration, macular telangiectasia, and polypoidal choroidal vasculopathy.
• Clinical features included deep retinal hemorrhages with feathery margins and petaloid patterns radiating from the fovea.
• OCT revealed hyper-reflectivity within the HFL, delineated by obliquely oriented fibers.

Conclusions:

• The characteristic petaloid-shaped, deep intraretinal hemorrhage with a feathery margin in the HFL is associated with a variety of disorders.
• Proposed terminology 'Henle fiber layer hemorrhage (HH)' to describe these clinical and OCT findings.
• Pathogenesis may involve abnormal retinal venous pressure from systemic/local retinovascular disorders or choroidal vascular abnormalities.