Eye Medicine

Ophthalmology

Diagnosis of eye problems requires use of a variety of techniques. Some of these, like the use of thermography illustrated here, are only occasionally required.

Horner's syndrome in a dog

Accurate assessment requires detailed visual examination of the surrounding structures and the accessible external surfaces of the eye itself, plus examination of the inside of the eye. For this various types of ophthalmoscope are used along with slit lamps. Extra eyelashes like those seen here are a common cause of corneal irritation and damage, but they are rarely this obvious.

Corneal damage allows special stains to penetrate into the surface aiding in detection of the problem and determination of its extent. Here there is a large corneal erosion, a common problem in boxer dogs.

Corneal ulcers of various types are also detected using fluorescein staining. Below is a stained dendritic ulcer viewed using ultraviolet light.

Not all eye problems are due to infection or damege. A variety of developmental conditions are recogniesed such as the persistence of parts of the pupillary membrane which should disapear before birth (below).

When theer are problems within the eye these can often be viewed using an ophthalmoscope. The surface texture, colouration and pattern of blood vessels within the retina can all indicate whether or not there are problems there.

The fluffy appearance of the optic disc shown here indicates that this dog, which had sudden onset blindness, has optic neuritis.

It is not always possible to see through the eye to the retina. Cataract (below right), inflammatory discharge, haemorrhage etc. within the eye can all obscure the view. When this is the case a combination of ultrasound scanning (bleow left) and electroretinography may be required to identify the location of problems within the eye.

Laser profilometry of the optic disc and retina

Once a diagnosis has been made, treatment can begin. This may just involve application of medications, but many eye problems require surgery.

It is not just cats and dogs that get eye problems! The picture below shows cataract in a Harris hawk.