When you notice something is happening to your pet's eyes, we will carry out a physical examination, not only of the eyes but also of the rest of the body. This is because, although most eye problems are primary, that is they start and finish in the eyes, others are secondary. They started elsewhere or involve other systems. For example, a single constricted pupil may mean eyeball damage but can also indicate nerve or brain injury. Allergy can cause conjunctivitis but often involves the skin, respiratory or digestive tracts. Sudden blindness in cats can be caused by high blood pressure. We usually use a combination of one or more of these diagnostic methods to determine the cause of your pet's eye condition.
Response To Treatment
Many conditions are reasonably self-evident to us. A complete response to treatment is both a cure and a confirmation of the diagnosis.
The ophthalmascope magnifies the surface of the eye, allowing us to see otherwise invisible corneal damage. The light from the ophthalmoscope shines on the retina, giving us a view of its texture and blood supply. When there are changes to the lens, such as cataract formation, the ophthalmascope helps us define exactly what is happening.
Even with an ophthalmoscope, corneal damage may be invisible. A sterile paper strip containing fluorescent dye is applied to the eye. Dye is retained by damaged corneal tissue, outlining the exact region and extent of injury.
Tear Production Measurement
Another sterile paper strip, when applied to the eye, soaks up tears. This can be used for measuring increased or decreased tear production.
Glaucoma is due to increased pressure within the eyeball. A tonometer measures pressure changes.
Tear Duct Flushing
Tears may overflow for a variety of reasons. We may choose to flush fluorescent dye into the nasolacrimal duct to see if it is patent.
Bacterial Culture And Sensitivity
If there is a green-yellow discharge, a bacterial culture and sensitivity may be taken to determine the best antibiotic to use in treatment.
A variety of blood tests are undertaken to determine the primary cause of eye conditions such as anterior uveitis.
If a mature cataract in the lens prevents the retina from being seen via an ophthalmoscope, electroretinography reveals the health of the retina. This form of diagnostics is usually carried out by Professor Peter Bedford.