From inflammation of the ciliary body, choroid or retina. Pupil
copperas green with white points, lines or patches, move in opposite
direction from the eye, liquefied vitreous, crystals of cholesterine,
scintillance, opacity. Treatment.
Opacities visible with the ophthalmoscope usually come from effusion of
blood into the vitreous, or inflammation of the retina, choroid, or
ciliary body. Blood thrown into the vitreous will usually leave some
permanent turbidity. In choroiditis or retinitis the ophthalmoscope may
reveal the changes in these structures. A turbidity appearing in the
anterior portion of the vitreous, without any apparent cause, is
probably due to cyclitis which cannot be seen with the ophthalmoscope,
but may cause special tenderness around the sclero-corneal zone. It is
common in recurrent ophthalmia of the horse and in irido-choroiditis in
animals generally, and may be a distinct feature of glaucoma. The
general reflection of the pupil is copperas green, but gray or white
points, lines, bars or patches may often be recognized. These being back
of the lens and axis of the eye, move in the opposite direction from the
line of vision, thus if the eye looks upward they descend, if it looks
downward they ascend, if it turns to the right, they turn to the left
and vice versa. Tested by a burning candle the three reflections remain
clear and distinct unless lens or cornea are affected.
Not infrequently the vitreous is found abnormally fluid, and among its
solid particles in affected horses have been found crystals of
cholesterin (Jacobi) and tyrosin (Möller). In the illuminated vitreous
such crystals may be seen to reflect the light like a shower of sparks
(synchysis scintillans). Opacity of the vitreous has been seen in cases
of amaurosis in horses (Hertwig) and glaucoma in lambs (Prinz).
_Treatment_ is rarely satisfactory, though in some recent cases, and in
the absence of any other irremovable lesion, reabsorption of a slight
exudate may take place, in connection with the use of mild saline
laxatives and diuretics.