Macular Degeneration Exudative Eye Left Clinical Trial
Official title:
OCTA Versus Structural OCT: Quantitative OCTA Biomarkers of Remission in Neovascular AMD
The objective is to find if there is a relationship between the Fractal Dimension, the gap, vascular density (VD), the surface, the span ratio and the status of the choroidal neovessels to adjust the interval between 2 intravitreal injections nor on the qualitative aspect of Optical Coherence Structural Tomography but also on quantified quantitative and objective values.
This quantification is based on the analysis of fractal dimension (FD, without unit),
lacunarity (Lac, without unit), vascular density (VD,%) and surface area of choroidal
neovascular ( CNV, mm2).
The fractal dimension of a vascular structure corresponds to its degree of complexity.
Fractals are models found in nature and biological systems that show self-similarity at
different magnifications. It is obtained from the "box counting" method calculating the
number of vascular segments contained in squares of varied size. Normal retinal vessels have
a known and quantified complexity (FD = 1.7).
A neovascular tumor treated with anti-angiogenics will reduce vascular density, losing its
random architecture; the investigators observe a return to a model standardized. NVCs have a
random organization. The lower the FD, the more random the vascular architecture.
Lacunarity represents the texture or the homogeneity of a lesion, this one is heterogeneous
when it is little vascularized and homogeneous if the vascularization is very dense. The
lower the lake, the more homogeneous the lesion.
FD and Lac are obtained in Angiography Optical Coherence Tomography (OCTA) by the analysis of
the hypersignal detected on the cut of the external retina.
The image is automatically binarised and skeletonized. NVC delineation is automatic and
associated with automatic background noise processing. This software is fully automatic whose
inter and intra grader reproducibility will be evaluated.
;