Integral-geometry characterization of photobiomodulation effects on retinal vessel morphology

Abstract

Abstract:The morphological characterization of quasi-planar structures represented by gray-scale images is challenging when object identification is sub-optimal due to registration artifacts. We propose two alternative procedures that enhances object identification in the integral-geometry morphological image analysis (MIA) framework. The first variant streamlines the framework by introducing an active contours segmentation process whose time step is recycled as a multi-scale parameter. In the second variant, we used the refined object identification produced in the first variant to perform the standard MIA with exact dilation radius as multi-scale parameter. Using this enhanced MIA we quantify the extent of vaso-obliteration in oxygen-induced retinopathic vascular growth, the preventative effect (by photobiomodulation) of exposure during tissue development to near-infrared light (NIR, 670 nm), and the lack of adverse effects due to exposure to NIR light. Willett, and L. E. H. Smith, "Quantification of oxygen-induced retinopathy in the mouse: a model of vessel loss, vessel regrowth and pathological angiogenesis," Nature Protocols 4(11), 1565-1573). 28. F. Matheron, Random Sets and Integral Geometry (John Wiley & Sons Inc, Feb. 1975 1591-1595 (1996). 36. L. D. Cohen and R. Kimmel, "Global minimum for active contour models: A minimal path approach," Int.

The dark art of light measurement: accurate radiometry for low-level light therapy

“… Turrioni et al [ 94 ] No info Source, LED (InGaN); wavelength, 450, 630 and 840 nm; power, –; frequency, –; beam area, – Irradiance, 88 mW/cm 2 ; time, 1 min 20 s and 8 min 40 s; energy, –; radiant exposure, 4 and 25 J/cm 2 The infrared LED irradiation at an energy density of 4 J/cm 2 and red LED at an energy density of 25 J/cm 2 were the most effective parameters for transdentinal photobiomodulation of cultured ondontoblast-like cell. Barbosa et al [ 95 ] No info Source, –; wavelength, 670 nm; power, –; frequency, –; beam area, – Irradiance, –; time, 3 min; energy, –; radiant exposure, 9 J/cm 2 Morphological image analysis was used to quantify the extent of vaso-obliteration in oxygen-induced retinopathic vascular growth, the preventive effect (by photobiomodulation) of exposure during tissue development to near-infrared light (670 nm) and the lack of adverse effects due to exposure to NIR light. Tang et al [ 97 ] No info Source, –; wavelength, 670 nm; power, –; frequency, –; beam area, – Irradiance, –; time, 160 s/day (2–9 months); energy, –; radiant exposure, 25 J/cm 2 Photobiomodulation potentially offers a non-invasive and cost effective therapeutic option for patients with non-centre-involving diabetic macular oedema.…”

Red Light Treatment in an Axotomy Model of Neurodegeneration

“…Treatment with 670 nm light has provided protection against cell loss in various rodent models of photoreceptor damage while demonstrating the safety of using 670 nm light with an irradiance of 60 mW cm −2 on this light‐sensitive tissue . Also, 670 nm light provided protection in other models retinal damage or dysfunction . In particular, treatment with 670 nm light in a rat model of partial axotomy (optic nerve transection) resulted in an improved vision, 7 days post injury .…”

Mean-intercept anisotropy analysis of porous media. II. Conceptual shortcomings of the MIL tensor definition and Minkowski tensors as an alternative

“…The Minkowski functionals and tensors are robust, efficient, and versatile structure measures, which have been successfully applied in physical 19,46 and biological systems 47,48 on all length scales from nuclear physics, 49,50 over condensed and soft matter 51,52 or plasma, 53 to astronomy and cosmology, [54][55][56] and to pattern analysis. 57 The Euler characteristic has already been widely applied in medical physics to characterize the connectivity of trabecular bone, 4,28,58,59 and R€ ath et al 60 have also used the other Minkowski functionals to characterize the structure of trabecular bone.…”