Our results assured the presence of functional association between the
pigment epithelium (P.E) and photoreceptors of eye retina of lacerta laevis. The
continuous effect of He-Ne laser on eye produce dangerous structure changes
(according to studi
es by transmission electron microscope) led to damage of
parts and organelles of pigment epithelium and photoreceptors of eye retina.
The displacement of the epithelium from the photoreceptors layer was the first
dangerous results on vision (Retinal detachment). This detachment conduced to
no protection of photoreceptors from high intense light (which usually
maintained by melanin pigments spread in epithelium cells surrounding the
outer segments [O.S] of photoreceptors) so that the outer segments of
photoreceptor became under the influence of intense light of He-Ne laser which
conduced to damage of cytoplasmic membrane of outer segment disks and
damage of chemical structure of visual pigments (pigment necessary for
discrimination of color in cones) so the photo sensible pole lost its function in
transferring the sign of light necessary for vision. The lesion happened by the
influence of He-Ne laser in the cones, associated by dangerous changes in the
retardation of nucleus size and damage of chromatin material and the absence
of organelles responsible for biological synthesis of cellular protein, and
deconstruction of glycogen molecules (energy mols.). The most dangerous thing
is the resulted damage of synaptic pedicle of cones (lost of connection between
bipolar nerve cells and synaptic ribbons) so the neurotransmission pole lost its
function in neurotransmission across the layer of neurosynapsis of retina. The
damaged photoreceptor cells (cones) (which were almost dead) became disables
to do their function in vision.
This paper proposes a new approach for the segmentation of the retina images to obtain the optic nerve and blood vessels regions. We used retinal images from DRIVE and STARE databases which include different situations like illumination variations, d
ifferent optic nerve positions (left, right and center). Illumination problem has been solved by preprocessing stage including image histogram-based illumination correction. Next, some morphological operations were used to filter the preprocessed image to obtain the ROI region, then, the center and radius of optic nerve were determined, and the optic nerve region was extracted from the original image. In blood vessels segmentation, we applied the illumination correction and median filtering.Then the closing, subtraction and morphological operations were done to get the blood vessels image which was thresholded and thinned to get the final blood vessels image.
The aim of this paper is to test the influence of the laser brightness on the
retina of eye of lacerta laevis, and the value of the distortion or damage in the
construction of photoreceptors (Cones), which are responsible of the viewing
process or
in the pigmentary epithelial layer which protect from the high light
intensity.
On the other hand, the continuation of the exposure to the He- Ne laser
beam the number of the damaged cells, that causes the loss of entire
photoreceptor layer. The results show similar effects at specular reflection.
Hence, it is very important to pay attention to the hazard emerged from the
laser beam in visible range, which requires to apply the special goggles, as well
as to keep the laser pointers out of reach of children.
