Written by Dr Michelle Trevan
If your pet has a sore eye, the “wait and see” rule does not apply. Eyes are an extremely important organ to look after. Not only do they allow our pets to see their doting owners, but they are a valuable tool for finding the food bowl, seeing their playmates and more importantly navigating the world around them!
A normal pet eye is clear, free of discharge and the sclera (or the whites of the eyes) are just that, white. Signs of a sore eye can include squinting, redness, rubbing at the eye, abnormal or increased discharge, changes in size of the eye and even changes in behaviour. As well as a thorough history, there are a range of eye tests that are performed, on your pet, to aid in a diagnosis.
Flouroscein is a special stain that can be applied to your pet’s eye to highlight any damage to the cornea. This stain turns an ulcer or a scratch bright green, making it easy for everyone to see. Once the ulcer has been identified, local anaesthetic drops may be applied, to numb the eye and allow us to check for, and flush out, any foreign bodies (eg grass seeds) lurking behind the eyelids. In many cases, some eye drops and pain relief will be prescribed to encourage healing of the cornea, but in more serious cases, surgery can be required to cover the ulcer while it heals.
A schirmer tear test is another important test that allows us to measure the amount of tear production in your pets eyes. A lack of tear production can result in gritty, sore, irritated eyes and pets will often rub at their eyes, or have repeat bouts of conjunctivitis. Occasionally this lack of tear production can be due to the immune system destroying the cells that produce tears, a condition called Keratoconjunctivitis sicca (KCS). If this is the case, a special eye cream is required that will lubricate the eye and aim to increase the tear production over time.
If we have concerns about glaucoma (or high pressure within the eye), it is very important that we check your pet’s intraocular pressure (IOP). To do this, we have a special instrument, called a Tonovet. It gives us an immediate reading and requires no sedation - just a gentle cuddle. Pressure increases, as seen with glaucoma, are a major concern, as if left untreated, they can lead to irreversible blindness and in some cases, rupture of the eye itself!
Other common eye changes can include a haziness or milky appearance to the eyes. Sometimes this can be a normal ageing-related change, called benign nuclear sclerosis, which just requires ongoing monitoring, but other cases it can be due to cataracts. It is important to differentiate between the two, as surgery can be performed to correct cataracts.
We are also fortunate enough, to have a visiting eye specialist (from Melbourne) come to the Animal Medical Centre every 2-3 months to see more complicated eye cases and referrals.