Advantages of Optical Coherence Tomography as a High Dynamic Range Imaging Modality in Subretinal Hyperreflective Material.

Abstract

We aim to describe the utility of high dynamic range optical coherence tomography (OCT) imaging to study subretinal hyperreflective material (SHRM) in patients with age-related macular degeneration (AMD). We retrospectively reviewed clinical information including visual acuity (VA) and OCT images (Heidelberg Engineering Inc., Germany) of patients undergoing antiangiogenic treatment for neovascular AMD and showing SHRM at baseline. We increased contrast between strong signal structures (high dynamic range image) re-classifying SHRM as hyperreflective, isoreflective and hyporeflective. We evaluated the patients at baseline, 3, 6 and 12-months follow-up. Forty-four eyes were classified as 15 hyperreflective (34.1%); 21 as isoreflective (47.7%); and 8 as hyporeflective (18.2%). During follow-up, hyporeflective SHRM disappeared in all cases, isoreflective SHRM faded in 16 cases (76,2%); hyperreflective SHRM remained in all cases. Hyporreflective SHRM showed a greater VA improvement than hyperreflective SHRM group (p=0,033). After 12-month follow-up only the hyporeflective and isoreflective groups significantly reduced the presence of fluid in 37,5% (p=0,250) and 46,62% (p=0,006) of the patients respectively; and outer retinal layers were disrupted more frequently in the presence of hyperreflective SHRM (ellipsoid zone, p=0,16; external limiting membrane, p=0,007). Contrast-enhanced OCT images enabled us to classify SHRM according to its reflectivity showing groups with different disappearance rates, visual acuity improvement and outer retinal layer disruption. This easy to access tool may be helpful as a prognostic factor in neovascular AMD cases.