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An Urban Experience
E. Giuliano1
1University of Missouri- Veterinary Medical Teaching Hospital, Columbia- MO, USA
The health of the eyelids is intimately linked with the health of the globe. As small animal practitioners, it is critical that we remember the importance of eyelids in relation to the preservation of vision. Adnexal structures function to protect the globe, produce 2 of the 3 components of the precorneal tear film, spread the
tear film over the corneal and conjunctival surfaces, prevent tear evaporation, and promote normal tear drainage. Physical or functional abnormalities of the eyelids may result in chronic irritation and ocular pain, corneal pathology, and even decreased vision or loss of the globe.
Conformational and acquired eyelid abnormalities
are common in small animal patients, with dogs
much more frequently affected than cats. The goal of treatment, whether surgical, medical, or combination
of both modalities, is the restoration of normal eyelid structure and function, within the conformational constraints of the individual patient and breed-
specific characteristics. Corrective eyelid surgery should be undertaken only with appropriate ocular instrumentation and suture material. The complete ophthalmic examination should always be performed prior to undertaking any definitive surgical repair to carefully rule-out underlying ophthalmic disease that may be contributing to a conformational or acquired eyelid disorder. Look carefully for differences in eyelid position or function that may occur after instillation of topical anesthetic solution (e.g. avoid over-correction
of entropion by blocking the “spastic component” of conformational eyelid entropion with topical anesthetic).
A basic understanding of adnexal anatomy is essential for the practitioner performing eyelid surgery. The eyelids consist of a fibrous tarsal plate (which is
poorly developed in the dog), which provides some structural rigidity to the eyelid, muscles primarily involved in blinking, thin, mobile and pliable skin on the outer surface, and palpebral conjunctiva on the inner surface. A number of adnexal specializations, such as cilia (eyelashes) and glands, exist in our small animal patients. Although species variability exit, typically cilia are present on the outer surface of the upper eyelid margin in dogs, horses, cattle, pigs, and sheep. A few cilia also are present on the lower eyelids of horses, cattle, and sheep. Cats have no true cilia but do have
a line of modified hairs that function similarly. Cilia have a protective role and may improve the sensitivity of the eyelids to potentially noxious stimuli, thereby increasing the speed by which reflexive blinking protects the globe. The tarsal or meibomian glands are modified sebaceous glands that are present within the tarsal plate and
open at the eyelid margin immediately posterior to the cilia. Their orifices are visible grossly, and mebum— a grayish-white secretion rich in phospholipids that has a lower melting temperature than sebum on the skin— is expressed from them; their opening forms an important surgical landmark, referred to as “the gray line” by some ophthalmologists. This small ridge of lipid along the eyelid margins helps minimize overflow of tears (epiphora). Mebum forms the more superficial lipid layer of the precorneal tear film, which adds stability to and reduces evaporation of the aqueous layer of the tear film.
Importantly, any blepharoplastic procedure should only be performed by the veterinarian who has personally evaluated the awake, non-sedated affected animal.
This helps to ensure that the practitioner performing eyelid surgery has a complete understanding of eyelid conformation and function of the patient and has properly planned his/her surgical technique. Evaluation and pre-surgical planning must be done prior to
general anesthesia. A complete ophthalmic exam,
with acquisition of the “minimal ophthalmic data base” (menace response, direct and consensual pupillary light reflex, palpebral reflex, Schirmer tear test, fluorescein stain, and tonometry) should be acquired in any patient presenting with an eyelid disorder. There are general “trends” in eyelid diseases that are important to be aware of even prior to examining a small animal patient. For example, the combination of ptosis and entropion
of the upper eyelid is commonly seen in breeds with abundant forehead skin folds. Treatment options include surgical reduction of skin folds, suspending the brows, enforced secondary granulation of the upper eyelid, or a combination of procedures. Lid-shortening procedures reduce corneal exposure, improve functional blinking and reduce likelihood of traumatic proptosis.
In some dog breeds with a broad skull base and redundant fascial skin, it is not uncommon to
diagnose an involuted lateral canthus with entropion and in such cases, surgical correction of this eyelid abnormality may be by application of traction to the lateral canthus, or by resection of the lateral canthal ligament. A combination of entropion, ectropion and macroblepharon may result in the presence of diamond shaped eyelids (e.g. the Clumber Spaniel) and indeed may even be considered “standard for the breed” in some cases. Surgical correction of this type of highly involved eyelid abnormality may involve the combination

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