Felipedia

1. Eyelid Agenesis (coloboma). Eyelid agenesis is a congenital defect of that occurs most frequently in cats. The upper temporal eyelid (lateral 1/3 to 2/3) fails to develop resulting in a full- or partial-thickness defect. Absence of eyelids results in secondary trichiasis and exposure keratoconjunctivitis. If the agenesis is mild, cryoepilation or entropion surgery can be performed to limit trichiasis. If severe, surgical correction requires use of grafting procedures, using the lower eyelid and the conjunctiva of the nictitating membrane as the donor site, to construct a functional eyelid.

2. Ankyloblepharon. Ankyloblepharon is adhesion of the eyelid margins to each other. Dogs and cats have physiologic ankyloblepharon until 10-14 days of age. If it persists past 15 days of age, infection of the conjunctival sac (ophthalmia neonatorum) may occur and is typified clinically by excessive swelling and/or discharge at the medial canthus (Figure 2). The eyelids should be separated using gentle (digital) traction. I recommend massaging the fused lids toward the medial canthus with a warm, wet cotton ball to effect separation. Exudate should be submitted for bacterial culture. The palpebral fissure should be flushed with sterile saline and a broad-spectrum antibiotic ointment applied topically q 6 h. Untreated neonatal conjunctivitis can lead to severe corneal scarring or loss of the globe.

3. Micropalpebral fissures. Narrowing of the palpebral fissures is usually associated with other concurrent congenital defects (entropion, microphthalmos) in the Shar Pei, Chow chow, Kerry blue terrier and Collie. Correction usually requires blepharoplastic surgical procedure in which conjunctiva is sutured to the incised eyelid surfaces to enlarge the fissure.

4. Macropalpebral fissures. Excessively large palpebral fissures is common in brachycephalic dog breeds with congenital exophthalmos (shallow orbits), the Bloodhound, St. Bernard, American and English Cocker spaniel. The dorsal sclera may be exposed and prominence of the globe may prevent closure of the eyelids while sleeping (nocturnal lagophthalmos). Secondary exposure keratitis may result in corneal pigmentation and fibrosis. Surgical shortening the palpebral fissure is indicated but must be performed where the abnormality exists (permanent lateral or medial canthoplasty).

5. Dermoid. A dermoid is a choristoma (normal tissue in an abnormal location). Dermoids may be present on the eyelid (Figure 3) but most frequently they are located on the lateral conjunctiva or cornea. Treatment requires surgical excision and is curative.

6. Conjunctivitis neonatorum. We now know that in kittens, conjunctivitis neonatorum is due to herpes virus infection. These kitties will benefit from appropriate antiviral medication. Cortisone medication should not be used in these patients. A lack of portions of the eyelid occurs in cats and is known as eyelid agenesis or eyelid coloboma. This condition is seen in the lateral portion of the upper eyelid. This condition will lead to scarring and blood vessels occurring in the cornea because tears are not spread normally and because hairs on the 'eyebrow' will rub the cornea. Surgery is necessary to correct this condition. An abnormality known as dermoids can occur along the conjunctiva (white of the eye) on the upper eyelid or along the lateral eyelid opening.


Conjunctivitis neonatorum	Agenesis (coloboma) of the upper lateral 2/3 of the eyelid is evident in this 6-month-old cat. Only the upper medial 1/3 of the lid is present. Trichiasis and fibrovascular keratitis are also present.