What is causing the red eye and ocular irritation in this Cocker Spaniel?
Now some of you will have noticed the tell-tale aphakic crescent on that first picture with diffuse illumination, but here on this one, taken as you might see it with distant direct ophthalmoscopy, its much more obvious. The lens has slipped down, allowing a crescent of bright light shining through where there is no lens to absorb any of it. This dog has a lens luxation with a cataractous lens and lens-induced uveitis (note the dark iris more obvious on the first picture) which have all conspired together to give an intraocular presure of 48mmHg. Treatment was difficult as the dog was old and thus we chose a medical rather than surgical option in this case and lowered the pressure successfully with Trusopt. The case shows, I hope, the value of the simple technique of distant direct ophthalmoscopy to view the lens against the tapetal reflection rather than just with incident light.