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OPD: Beginner cataract

A patient has a feeling of decreased vision in one eye (right eye), while his acuity without correction 10/10 and 12/10 with a very slight correction ofastigmatism myopic: plan (-0.25 x 0 °). The patient reported a few symptoms compatible with those of a debutante cataract (glare, difficulties in against day).

Examination to the lamp (biomicroscope) slot, there is a discreet opalescence of the center of the lens (nuclear opalescence) of the right eye.

opalescence beginner cataract

Appearance in the review to the lamp (biomicroscope) slot of the anterior segment of the eye: note the discreet opalescence of the central part (core) of the lens (arrow).

The aberrometrique survey with the OPD SCAN 3 shows that there is a slight elevation of the optical irregularity, seemingly original internal, since the cornea does not have irregular astigmatism (red box).

OPD beginner cataract

Statement aberrometrique OPD SCAN 3: left, map OPD (variations of the refraction in the pupil), in the Center, corneal topography (axial mode), right: refraction related to the internal dioptres (later of the cornea and crystalline face). The red box shows that there is a rise in the rate of eye aberrations of internal origin (since the corneal aberrations rate is close to zero)

It was noted that the quality of the stigma (maps of the) PSF (: Point Spread Function, framed black and white next to the maps in color) is less in terms of the internal dioptres for the cornea.

An expansion of these images confirms it:

Point spread function (PSF) cataract debutante fovea cones

The only comparison between images PSF (Point Spread Function; the point spread function) for the entire eye (left), the anterior cornea (in the Center) and the internal dioptres (right). The magnification of the PSF of the entire eye shows that sprawl of the image of a point source (which in one eye 'optically perfect', should be almost limited) concerns only a number limited to photoreceptors (the yellow wire represents the mosaic of the cones in the fovea).

To better interpret them, we can overlay the mosaic of photoreceptors (cones) in the image of bright sprawl (at the bottom of the image above): we found that the spatial extension of this light spread (PSF) is low, which allows a good resolution, but results in a lower contrast of the retinal image.

The study of fluctuations of the refractive power shows a slight "myopisation" Central: it is certainly induced by an increase in the refractive index of the lens (index myopia) that often accompanies the appearance of cataract.

map OPD beginner cataract

This map shows the fluctuations of the refraction within the pupil for the entire eye: an increase of the (Central myopisation: myopia of index in this context).

This suggests the beginner cristalliniennes opacities responsibility in the genesis of these disorders: it is a "pre cataract", or a beginning of nuclear cataract. There is no formal operative indication due to the gene that is moderate, and the preservation of Visual acuity. A measure of the light distribution (collection of the OSI: 'Optical Scatter Index', performed with the instrument) OQAS) is indicated: this technology allows to objectify the effects of the loss of transparency of the lens on the Visual function (see article on) indicators provided by the OQAS and cataract)


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