Eye Injuries

Eye Injury

If you notice any of the following:

Your dog squinting, rubbing eye or excessive tear production.
Any suspected trauma to the eye.
Abnormal appearance to the eyeball.
Excessive redness to the white part of the eye – sclera “Red Eye”.
Any time the eyelids cannot cover the eyeball.

You should seek veterinary attention immediately as these signs can indicate potentially serious eye problems which can risk your dog’s vision.

How an eye works
Two oblique muscles, the dorsal and ventral, help apply tension, or rotation to the globe.

The superior oblique muscle results in rotating the globe in a downward direction.

Dogs also have retractor oculi muscle which enables them to retract the globe, a sign of ocular pain. This ability is limited in brachycepitalic dogs.

Muscle

Primary Action
Cranial Nerve Innervation

Dorsal Rectus
Upward Rotation
III (oculomotor nerve)

Ventral Rectus
Downward Rotation
III

Lateral Rectus
Lateral Rotation
VI (abducens nerve)

Medial Rectus
Medial Rotation
III

Dorsal Oblique
Rotation Downward & Inward
IV (trochlear nerve)

Ventral Oblique
Rotation Downward & Inward
III

Retractor Bulbi
Globe Retraction
VI

Basic clinical examination of eye:

Globe position – symmetry of globes: is each globe directed forward equally or is one globe deviated?
Squinting – known as “strabismus”: is it painful to the patient?

A good tip – examine eyes from above to help recognise exophthalmos and enophthalmus.

Remember that a bupthtalmic globe will show enlarged or anteriorly displaced, measure corneal diameter of eye globe.

Clinical Tip: If in doubt whether eye is enlarged or anteriorly displaced, measure corneal diameter of eye globe.

Retropulsion of globe: is one globe more resistant to retropulsion – possible space – occupying lesion of retrobulbar space.

Clinical Tip: If patient is co-operative, but in pain, without opening mouth use the index finger to “slide” under the upper lip to palpate the area behind the last upper molar tooth.

EXOPTHALMOS

This is a forward (rostral) displacement of the globe.
It must be differentiated from buphthalmos – an increase in size of globe.
The term proptosis usually refers to when the eye appears out of its socket.

Clinical Signs of Exophthalmos

Decreased vision (if retina/or optic nerve affected).
Ocular discharge
Squinting (strabismus) deviation of globe.
Protrusion of third eyelid.
Chemosis – Conjunctival and eyelid swelling.
Inability to close eyelids – lagophthalmas.
Exposure keratitis – typically affecting the cornea as a central or horizontal band.

Exophthalmus is one of the most common orbital problems in dogs.

Acute onset, painless bilateral exophthalmus in a dog may be a result of muscular problem known as extra-ocular polymyasites syndrome. Unilateral exophthalmus accompanied by pain, resistance to opening of the mouth, lethargy and inappetence may be due to retrobulbar infections, abscesses, cellulites from an anal cavity foreign body and require veterinary attention immediately.

Chronic, non painful exophthalmus is often a result of tumours (neoplasia), particularly in the elder patient. Approximately 91% of orbital tumours are malignant and most are primary.

ENOPHTALMOS

Is a recession of the globe into the orbit and must be differentiated from a small globe as in congenital microphthalmos or acquire shrinkage of the globe (pthtisis bulb).

Clinical Signs of Enophthalmos

Caudal displacement of globe.
Protrusion of III eyelid.
Narrowed palpebral fissure.
Increased space between globe and eyelids.
Accumulation of mucus in conjunctival fornix.

Causes of Enophthalmos

Commonly occurs in dogs with painful ocular lesions and is due to retraction of the globe by the retractor bulbi muscles. Recession of the globe into the orbit also occurs if orbital fibrosis develops after inflammation, trauma, haemorrhage, or surgery. Loss of orbital fat due to starvation, dehydration or metabolic disease will result in enophthalmos.

Horner’s syndrome, a disruption of the sympathetic innervation to orbital ocular smooth muscle, results in enophthalmos accompanied by:

Drooping of upper eyelids’ (ptosis).
Pupil in affected eye is more constricted than the fellow normal eye (this is known as miosis).
Third eyelid protrusion.
Slight sclera congestion.

PROPTOSIS OF THE GLOBE

When the globe protrudes from eye socket.

Brachycephalis breeds have shallow orbits with a flat, medial wall. Proptoisis of the globe is easily accomplished with only minor amount of digital pressure and commonly results from blunt trauma such as car accidents and arguments with other dog’s over food or favourite toys. An accompanying medial rectus muscle avulsion is common and leads to a lateral squint (strabismus) in addition to the proptosis.

When proptosis occurs, immediate management consist of keeping the globe moist and seek veterinary attention immediately.

Conditions such as trauma, glaucoma (increased intra-ocular pressure), and perforation of the cornea, serious infections, foreign bodies and auto immune diseases can all affect your dogs eye and may need medical attention.

NB: Take care not to get bitten when treating your dog and use a muzzle for safety.

What To Do

If an eye has been dislocated from the socket (proptosis), or the lids cannot close over the eyeball, keep the eyeball moist with contact lens solution, K-Y-Jelly, water or moist compress.
If an irritating chemical or other product accidently gets into the eye, flush it with running water, contact lens solution or homemade saline solution squeezed from a compress, or a sponge for a minimum of 15 minutes (saline: dissolve 2 teaspoons of salt in 2 pints of water).
Always seek immediate veterinary attention. Eyes are quite fragile and just a few minutes could mean the difference between sight and blindness. Referral to an eye specialist may be required in more serious conditions.

What Not To Do

Do not attempt to treat eyes, or remove foreign bodies yourself.
Do not try to push proptosed (dislocated eyeball) back into socket. This must be done under general anaesthesia so as not to cause further damage to the eyeballs interior.