SPOTTING AN OPHTHALMIC EMERGENCY is easy: any pet coming into the practice with eyes that are non-responsive, red, painful, discharging or otherwise abnormal should be viewed as needing immediate assessment and treatment, VNs were told at VetsSouth 2017 in February.
Pip Boydell, a neuro-ophthalmologist at the Animal Medical Centre referral centre in Manchester, warned the nurses to take no risks when dealing with such emergencies.
“In some clinical disciplines you can often put right any mistakes that you make in your early management of a case, but where the eyes are concerned you may not get a second chance,” he said.
VNs may not be allowed to diagnose or treat ophthalmic emergencies, but they can have a pivotal role in determining whether an animal receives the treatment it needs – and in good time, he suggested.
As revealed by a range of slides from his casebook, the extent of the visible changes in the eyes due to disease or injury can have little relationship with their potential consequences for the organ’s function. So it is highly unlikely that pet owners will have a clear understanding of the urgency with which they should seek treatment, he said.
So it is important for nurses to answer in the affirmative if called by a client and asked if they should bring in the pet for an ophthalmic consultation and to encourage owners to attend should they change their minds after having called for an ophthalmic appointment.
“The classic scenario is a new puppy that gets on the wrong side of a resident cat and gets a swipe. The owners comfort the puppy, it eventually calms down and they make a mental note to have the eyes checked over later.
“What they don’t know is that the scratch can set off an inflammatory pathway leading to uveitis and secondary glaucoma. Those changes may not be obvious for maybe 10 days by which time the puppy is glaucomatous and blind and there is nothing we can do about it. We must get about 20 cases like that every year at our clinic.”
Clients should be encouraged to seek early treatment even for conditions that would not normally be viewed as an emergency – and for which the owner may have even had some prior warning could occur.
“Luxated lenses, for example, is an inherited condition and in time it is likely that it will develop in both eyes. Unfortunately, I am often sent cases in which it’s the second eye that needs treatment – it’s already too late for the first.”
But even when an ophthalmology case is seen by a clinician, there is still no guarantee that it will always receive the right treatment.
Dr Boydell noted that few first opinion practitioners have the experience and equipment needed to make a full examination of the back of the eye.
“When an animal appears with a painful, inflamed eye, there is a temptation to regard it as a straightforward conjunctivitis case and treat accordingly. But many conditions can involve the retina and other structures deep within the eye and so I would encourage inexperienced clinicians to ask a colleague in the practice or outside to have a look.”
Whatever condition is diagnosed, the clinical staff should be ready to provide immediate treatment to relieve pain and attempt to control any degenerative changes.
In cases of “melting ulcers”, the corneal damage can progress at a startlingly fast rate. The condition may be treated by blocking the production of the collagenase enzymes produced by the damaged cells or by Pseudomonas bacteria with anti-collagenase agents such as EDTA, acetylcysteine, heparin or autologous serum.
Meanwhile, for a broad range of conditions affecting the eyes of both dogs and cats, the most versatile treatment is one of the oldest ocular drugs, atropine. Dr Boydell encouraged all practices to have the drops ready to dilate the pupil, prevent the development of uveitis and help in providing relief from pain.
Dr Boydell coaxed responses from his audience on their approach to dealing with a range of different ocular conditions, including the worst-case scenario of an animal presenting in the middle of the night belonging to their own mother-in-law.
He showed that the apparent severity of traumatic injury might be unrelated to the urgency needed in the response. In many cases, when an animal is presented out-of-hours the best option may be appropriate intensive medication rather than attempting surgery.
He also warned that there is no point in carrying out an intricate surgical procedure when there is no chance that the animal will retain any vision in the affected eye.