High-Resolution Imaging by Adaptive Optics Scanning Laser Ophthalmoscopy Reveals Two Morphologically Distinct Types of Retinal Hard Exudates.

Muneo Yamaguchi,Atsunobu Takeda,Shizuo Mukai,Shintaro Nakao,Tatsuro Ishibashi,Yoshiyuki Kobayashi,Yasuhiro Ikeda,Yuji Oshima,Yoshihiro Kaizu,Takahito Nakama,Mitsuru Arima,Koh-Hei Sonoda,Shigeo Yoshida

doi:10.1038/srep33574

Muneo Yamaguchi, Atsunobu Takeda + Show 11 more

Open Access

https://doi.org/10.1038/srep33574

Copy DOI

Journal: Scientific Reports	Publication Date: Sep 19, 2016
Citations: 18	License type: CC BY 4.0

Affiliation: Kyushu University

Abstract

Histological studies from autopsy specimens have characterized hard exudates as a composition of lipid-laden macrophages or noncellular materials including lipid and proteinaceous substances (hyaline substances). However, the characteristics of hard exudates in living patients have not been examined due to insufficient resolution of existing equipment. In this study, we used adaptive optics scanning laser ophthalmoscopy (AO-SLO) to examine the characteristics of hard exudates in patients with retinal vascular diseases. High resolution imaging using AO-SLO enables morphological classification of retinal hard exudates into two types, which could not be distinguished either on fundus examination or by spectral domain optical coherence tomography (SD-OCT). One, termed a round type, consisted of an accumulation of spherical particles (average diameter of particles: 26.9 ± 4.4 μm). The other, termed an irregular type, comprised an irregularly shaped hyper-reflective deposition. The retinal thickness in regions with round hard exudates was significantly greater than the thickness in regions with irregular hard exudates (P = 0.01 →0.02). This differentiation of retinal hard exudates in patients by AO-SLO may help in understanding the pathogenesis and clinical prognosis of retinal vascular diseases.

Highlights

Retinal imaging techniques have undergone rapid and significant improvements in recent years
In this study, we investigated the morphological characteristics of hard exudates in patients with retinal vascular diseases using adaptive optics scanning laser ophthalmoscopy (AO-SLO), in an attempt to correlate these findings with clinical characteristics and histological data previously described in the literature
AO-SLO observation showed hard exudates as hyper-reflective patterns, and two distinct morphologies of hard exudates could be seen even though they could not be distinguished by color fundus photograph or by spectral domain optical coherence tomography (SD-OCT) (Fig. 1A,B,D,E)

Summary

Introduction

Retinal imaging techniques have undergone rapid and significant improvements in recent years. In this study, we investigated the morphological characteristics of hard exudates in patients with retinal vascular diseases using AO-SLO, in an attempt to correlate these findings with clinical characteristics and histological data previously described in the literature. AO-SLO observation showed hard exudates as hyper-reflective patterns, and two distinct morphologies of hard exudates could be seen even though they could not be distinguished by color fundus photograph or by SD-OCT (Fig. 1A,B,D,E).

Results

Conclusion