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Ocular Examination

Key Point: Performing an ocular exam illustrates the

systematic procedure needed to perform a thorough

and effective physical examination.

V.2.3

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Examination of the Eyes

⮞V.2.3 PowerPoint: Ocular Exam

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Eyelids and Eyelashes

Medial canthus

Lateral canthus

Nictations or third eyelid

Pupil

Iris

⮞V.2.3 PowerPoint: Ocular Exam

The canthus (plural canthi, palpebral commissures) is either corner of the eye where the upper and lower eyelids meet. More specifically, the inner and outer canthi are, respectively, the medial and lateral ends or angles of the palpebral fissure.

During the subjective or observation portion of the physical examination of the eyes, the examiner will look at the eye and surrounding structures without using hands to physically examine the eyes. The examiner will pay attention to the pupil, iris and anterior or aqueous chamber of the eye. The examiner will note how the eyelids “lie” on the eye and will examine the third eyelid, as well. The examiner will also note any discharges, swelling, discoloration or anatomical abnormalities that may be present.

Reference:

Kallerna. (n.d.). Eye of Horse [Photograph]. In Creative Commons Attribution Share Alike 3.0 Unported license.

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Prolapse of the accessory tear gland from behind the third eyelid

“Cherry Eye”

⮞V.2.3 PowerPoint: Ocular Exam

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Entropion of the lower eyelid with secondary scarring of the cornea

⮞V.2.3 PowerPoint: Ocular Exam

Entropion

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Eye or globe

Upper eyelid

Lower eyelid

Conjunctiva

⮞V.2.3 PowerPoint: Ocular Exam

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Infectious Conjunctivitis in this kitten is caused by feline viral rhinotracheitis infection.

⮞V.2.3 PowerPoint: Ocular Exam

Infectious Conjunctivitis

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cornea

Eye

Anatomy

⮞V.2.3 PowerPoint: Ocular Exam

suspensory ligaments

This cross-section of the eye shows the internal anatomy of the eye. The lens and its suspensory structures divide the eye into a large posterior vitreous chamber and a small anterior aqueous chamber. Vitreous humor is a gel-like substance that fills the vitreous chamber. It is static and does not change in volume over the life of the animal. The aqueous humor that fills the anterior or aqueous chamber is dynamic. It is constantly produced and constantly drains from the eye.

The cornea is a continuation of the sclera. These two structures make up the outer covering or tunic of the eye.

The middle tunic of the eye includes the choroid and iris. The middle tunic is considered to be the vascular tunic of the eye.

The retina is the inner tunic of the eye and is a neural structure. The optic nerve is the beginning of the pathway of nerves that carry visual stimuli to the brain.

Reference:

Hortsch, M. Anatomy of the Eye [Drawing]. The Second Look Series. Open.Michigan/ MichiganeHistology

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Corneal ulcer stained with fluorescein stain

Corneal Ulcer

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What do you see?

⮞V.2.3 PowerPoint: Ocular Exam

Observations

Notice any abnormal findings with the eyes of the cat in the picture up above. Students should notice the following:

⮞ Miosis: This is a smaller pupil size in the right eye.

⮞ Ptosis: This is droopy lids or closed lids in the right eye.

⮞ Enophthalmos: This is a shrinking of the right eye further into the socket.

⮞ Prolapse of the nictitans or third eyelid: Students might recognize that as the globe of the right eye shrinks further into the socket, it allows the third eyelid to move more prominently across the eye. This will be the hardest change for students to appreciate.

This condition is called Horner’s Syndrome, and it is typically caused by an inflammation of the middle ear. Some nerves that supply the eye run very close to the middle ear and can be affected by the change in the middle ear. If a veterinarian successfully treats the ear problem, the Horner’s Syndrome will resolve itself.

Reference:

Uploaded by Aqwis. (n.d.). Horner’s Syndrome. Retrieved from <div xmins:cc=“http:// creativecommons.org/ns#" xmlns:dct="http://purl.org/dc/terms/" about="http:// open.umich.edu/education/med/resources/second-look-series"><span property ="dct:title">The Second Look Series</span>(<a rel="cc:attributionURL" property="cc:attributionName" href="http://open.umich.edu/education/med/ resources/second-look-series">Michael Hortsch</a>) / <a rel="license" href=“ http://creativecommons.org/licenses/by-nc/4.0/">CC BY-NC 4.0</a></div>–The Second Look Series (Michael Hortsch)/CC BY-NC 4.0 Creative Commons CC BY SA 3.0 license