Imaging of vascular wall fine structure in human retina using adaptive optics scanning laser ophthalmoscopy.

Investigative Ophthalmology & Visual Science

PubMedID: 24071955

Chui TY, Gast TJ, Burns SA. Imaging of vascular wall fine structure in human retina using adaptive optics scanning laser ophthalmoscopy. Invest Ophthalmol Vis Sci. 2013;54(10):7115-24.
Purpose: 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 8 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 10x Airy disk confocal aperture. Retinal arteries and arterioles were divided into 4 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 8 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 Group 2 and 3 vessels, 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 normal subjects using AOSLO with multiply scattered light imaging for retinal vessels with a lumen diameter =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.