OPACITY OF THE VITREOUS. 



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, scintiHance, opacity. 

 Treatment. 



Opacities visible with the ophthahiioscope usually come from 

 effusiou of blood into the vitreous, or iuflannnation of the retina, 

 choroid, or ciliary body. Blood thrown into the vitreous will 

 usually leave some permanent turbidity. In choroiditis or re- 

 tinitis the ophthalmo.scope may reveal the changes in these 

 structures. A turbidity appearing in the anterior jiortion of the 

 vitreous, without any apparent cause, is probably due to cyclitis 

 which cannot be seen with the ophthalmoscope, but may cause 

 special teirderncss around the sclero-corneal zone. It is common 

 in recurrent ophthalmia of the horse and in irido-choroiditis in 

 animals gen-erally, 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 thej' ascend, if it 

 turns to the right, they turn to the left and vice versa. Tested 

 by a burning candle the three refiectious remain clear and 

 distinct unless lens or cornea are affected. 



Not infrequently the vitreous is found abnormalh' fluid, and 

 amoug its solid particles in afTected hor.ses have been found crys- 

 tals of cholesterin (Jacobi) and tyrosin (Moller). In the illumi- 

 nated vitreous such crystals may be seen to reflect the light like a 

 .shower of sparks (synchysis .scintillans). Opacity of the vitre- 

 ous has been seen in cases of amaurosis in horses (Hertwig) and 

 glaucoma in lambs ( Prinz). 



Treatmeiit is rarely satisfactory, though in some recent cases, 

 and in the ab.sence of any other irremovable lesiou, reab.sorption 

 of a .slight exudate may take place, in connection with the use of 

 mild saline laxatives and diuretics. 



437 



