Multiply scattered light tomography and confocal imaging: detecting neovascularization in age-related macular degeneration

Abstract

A novel technique, Multiply Scattered Light Tomography (MSLT), and confocal Infrared Imaging are used to provide diagnostic information using a comfortable, rapid, and noninvasive method. We investigated these techniques in detecting neovascularization in age-related macular degeneration. The MSLT used a Vertical Cavity Surface Emitting Laser (VCSEL) at 850 nm, while the confocal imaging technique used either the VCSEL or a 790 nm laser diode. Both were implemented into the topographical scanning system (TopSS, Laser Diagnostic Technologies, Inc.) Confocal imaging with both lasers provided different information about neovascularization as a function of focal plane, and different also from MSLT.

Imaging translucent cell bodies in the living mouse retina without contrast agents

“…Our approach builds on earlier work from Elsner et al [9] who showed that the contrast of features obtained with a scanning laser ophthalmoscope could be enhanced by offsetting the confocal detection aperture, Chui and colleagues [10] incorporated this principle in an adaptive optics scanning laser ophthalmoscope (AOSLO) observing increased contrast at the blood vessel wall, and flowing blood cells within the vascular network. Sulai and colleagues [11] improved this method by blocking the center of the light distribution in the detector plane and capturing the remaining light to the left of the center in one detector, and the light to the right of center in another.…”

Imaging individual neurons in the retinal ganglion cell layer of the living eye

“…S1). The explanation for the difference between these modalities and conventional on-axis confocal imaging put forth by Elsner et al, is that shifting detection away from the optical axis increases the fraction of light reaching the detector that is multiply scattered by the retina (20,23,27). Here we sought through empirical investigations to better understand how detection can be optimized to image the nearly transparent inner retina.…”

Imaging a Child's Fundus Without Dilation Using a Handheld Confocal Scanning Laser Ophthalmoscope

“…The macula in children can have a striking bull'seye appearance due to the higher reflectance from the vitreoretinal interface along the foveal slope. 20 Although the margin of the disc is delineated in some cases, at other times it is indistinguishable from the coplanar retina. The presence of a peripapillary crescent clearly delineates the disc margin from the adjacent retina.…”

“…Failure to detect optic disc pallor was likely due to the similar reflectance of the 780-nm scanning light from the normal and atrophic discs. Future modification of the laser wavelength or the use of non-confocal scattered-light images 20,23 might allow for better assessment of optic nerve pallor.…”