Imaging of vascular wall fine structure in the human retina using adaptive optics scanning laser ophthalmoscopy.
OBJECTIVE
To improve the ability to image the vascular walls in the living human retina using multiply-scattered light imaging with an adaptive optics scanning laser ophthalmoscope (AOSLO).


METHODS
In vivo arteriolar wall imaging was performed on eight healthy subjects using the Indiana AOSLO. Noninvasive imaging of vascular mural cells and wall structure were performed using systematic control of the position of a 10× Airy disk confocal aperture. Retinal arteries and arterioles were divided into four groups based on their lumen diameters (group 1: ≥100 μm; group 2: 50-99 μm; group 3: 10-49 μm; group 4: <10 μm).


RESULTS
Fine structure of retinal vasculature and scattering behavior of erythrocytes were clearly visualized in all eight subjects. In group 1 vessels the mural cells were flatter and formed the outer layer of regularly spaced cells of a two (or more) layered vascular wall. In the vessels of groups 2 and 3, mural cells were visualized as distinct cells lying along the lumen of the blood vessel, resulting in a wall of irregular thickness. Vascular wall components were not readily identified in group 4 vessels.


CONCLUSIONS
Our results show that retinal vascular mural cells and wall structure can be readily resolved in healthy subjects using AOSLO with multiply scattered light imaging for retinal vessels with a lumen diameter greater than or equal to 10 μm. Our noninvasive imaging approach allows direct assessment of the cellular structure of the vascular wall in vivo with potential applications in retinal vascular diseases such as diabetes and hypertension.
School of Optometry, Indiana University, Bloomington, Indiana.
Toco Y P
TY
Chui
Thomas J
TJ
Gast
Stephen A
SA
Burns
D000293:Adolescent; D000328:Adult; D001160:Arterioles / Q000033:anatomy & histology; D042783:Endothelial Cells / Q000166:cytology; D005260:Female; D006801:Humans; D008297:Male; D055806:Microvessels / Q000033:anatomy & histology; D008875:Middle Aged; D032389:Myocytes, Smooth Muscle / Q000166:cytology; D009887:Ophthalmoscopy / Q000379:methods*; D012171:Retinal Vessels / Q000033:anatomy & histology*; D014699:Venules / Q000033:anatomy & histology; D055815:Young Adult
adaptive optics scanning laser ophthalmoscope; blood vessels; dark field imaging; endothelial cells; pericytes; retina