A rapid response needed!

 This 2 year old Springer spaniel has gone blind suddenly in this red painful eye. What is the lilely diagnosis and what is the necessary emergency treatment?

Note the hazy cornea and the moderately dilated pupil. A red painful eye could be uveitis or glaucoma but even if you haven’t a tonometer to measure the intraocular pressure, the dilated pupil tells you its glaucoma rather than uveitis. The intraocular pressure actually was 56mmHg.

In the old days we would have used intravenous mannitol to reduce the pressure, but these days the topical prostaglandin analogue Xalatan has a wonderful effect, opening new drainage channels in the choroid and reducing the pressure rapidly. One drop lowered the intraocular pressure to 16mmHg within fifteen minutes, with a concurrent miosis of the pupil too.

 The nice thing is that the owners can monitor the response to treatment easily without recourse to a tonometer. A small pupil indicates an acceptable intraocular pressure while a mydriastic pupil shows that another drop of Xalatan is needed. We do have to worry that the other eye may develop the condition too, so a drop of Xalatan before bedtime will push back any such an event by a long time.