title: High-Resolution Imaging by Adaptive Optics Scanning Laser Ophthalmoscopy Reveals Two Morphologically Distinct Types of Retinal Hard Exudates.
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 = 0.02). This differentiation of retinal hard exudates in patients by AO-SLO may help in understanding the pathogenesis and clinical prognosis of retinal vascular diseases
authors.affiliation: Department of Ophthalmology, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan.
authors.forename: Muneo
authors.initials: M
authors.lastname: Yamaguchi
authors.affiliation: Department of Ophthalmology, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan.
authors.forename: Shintaro
authors.initials: S
authors.lastname: Nakao
authors.affiliation: Department of Ophthalmology, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan.
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Kaizu
authors.affiliation: Department of Ophthalmology, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan.
authors.forename: Yoshiyuki
authors.initials: Y
authors.lastname: Kobayashi
authors.affiliation: Department of Ophthalmology, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan.
authors.forename: Takahito
authors.initials: T
authors.lastname: Nakama
authors.affiliation: Department of Ophthalmology, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan.
authors.forename: Mitsuru
authors.initials: M
authors.lastname: Arima
authors.affiliation: Department of Ophthalmology, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan.
authors.forename: Shigeo
authors.initials: S
authors.lastname: Yoshida
authors.affiliation: Department of Ophthalmology, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan.
authors.forename: Yuji
authors.initials: Y
authors.lastname: Oshima
authors.affiliation: Department of Ophthalmology, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan.
authors.forename: Atsunobu
authors.initials: A
authors.lastname: Takeda
authors.affiliation: Department of Ophthalmology, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan.
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Ikeda
authors.affiliation: Retina Service, Department of Ophthalmology, Massachusetts Eye and Ear Infirmary, Harvard Medical School, Boston, Massachusetts, USA.
authors.forename: Shizuo
authors.initials: S
authors.lastname: Mukai
authors.affiliation: Department of Ophthalmology, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan.
authors.forename: Tatsuro
authors.initials: T
authors.lastname: Ishibashi
authors.affiliation: Department of Ophthalmology, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan.
authors.forename: Koh-Hei
authors.initials: KH
authors.lastname: Sonoda