Two Types of Curved Hyperreflective Structures on Optical Coherence Tomography Images of the Outer Retina of Eyes with Different Macular Disorders

Abstract

Hyperreflective materials on Spectral-Domain Optical Coherence Tomography (SD-OCT) images of eyes with different retinal disorders may have diverse shapes and origins and are a prognostic marker of disease progression. This study documents using SD-OCT the presence of Curved Hyper Reflective Structures (CHRS) in the outer macula of eyes with different retinal disorders. A retrospective case series of 22 eyes of 21 patients with CHRS is described. In addition, 12 eyes of 12 patients with other kinds of intra retinal hyperreflective structures were investigated. CHRS, which form curved thin lines or broad bands between the outer plexiform layer and external limiting membrane (ELM) in the macula, were found in eyes without edema. Thin CHRS were secondary to dry age-related macular degeneration (AMD; n=10 eyes), glaucoma (n=2), wet AMD, chorioretinitis, macular scarring, anterior ischemic optic neuropathy, proliferative diabetic retinopathy, adult-onset foveomacular vitelliform dystrophy, and ocular ischemia (each n=1), respectively. Broad CHRS were caused by hemorrhages in the inner foveal layers (n=3). CHRS were associated with focal photoreceptor layer defects. The defects were present before the formation of thin CHRS and during or after the formation of broad CHRS. The retina of eyes with edema showed hyper reflective foci and cystoid cavities which contained hypoor medium-reflective fluid and hyper reflective material, but not CHRS. It is concluded that CHRS in the outer macula are found in eyes with different retinal disorders without edema. Thin CHRS likely develop after photoreceptor damage from the ELM. Broad CHRS are caused by hemorrhages within the inner foveal layers.