![]() Impairment of the optic nerve and the optic chiasm resulted in mydriasis and blindness.ĭiseases of the feline eyelids are similar to those that occur in the dog, but inherited defects are far less frequent. (D) Orbital lymphoma in this cat resulted in exophthalmos, deviation of the globe off its axis, and exposure. (C) Orbital extension of squamous cell carcinoma from the nasal passages resulted in exophthalmos in this cat. (B) This cat had a neoplasm in the ventral floor of the orbit that extended from the oropharynx and resulted in dorsal deviation of the globe and elevation of the nictitans. It is unilateral or bilateral.įigure 14.4(A) Orbital neoplasms are often squamous cell carcinomas that arise from the eyelids and conjunctiva, as in this cat, and subsequently invade the orbit. Orbital lymphosarcoma is a common orbital tumor in cats. Others arise in the nasal passages and invade outward into the orbit. Many of the tumors arise from the conjunctiva, nictitating membrane, or eyelids and invade the orbit from there. About 90% are malignant, and about 60% of these tumors are squamous cell carcinomas ( Figure 14.4). Orbital neoplasia occurs in cats, but reports are less frequent than in dogs. Note the exophthalmos, conjunctival swelling and hyperemia, and the dull, dry central cornea (the result of exposure). (B) Another example of orbital cellulitis in a cat. The signs for orbital cellulitis in cats are much more subtle than in the dog. Treatment is the same as for the dog.įigure 14.3(A) Orbital cellulitis in a cat presented as exophthalmos, swollen eyelids, and secondary iridocyclitis (miosis). Both bacteria and fungus ( Penicillium sp.) have been isolated. As the orbital space is more limited in cats, orbital inflammations rapidly cause protrusion of the nictitans, conjunctival hyperemia, localized orbital pain, and limited exophthalmos ( Figure 14.3). The clinical signs and treatment of orbital inflammations in cats are similar to those in dogs. The prognosis for the return of vision in cats is poor. Replacement of the globe and short‐term complete temporary tarsorrhaphy should be performed as soon as possible. The prognosis for successful globe replacement and return of vision is very poor. The pupil is dilated and unresponsive to light. ![]() Note the marked drying and desiccation of the unprotected cornea. Damage to the contralateral optic nerve can result in blindness of the fellow eye.įigure 14.2(A) Marked proptosis in a cat of several hours duration. Optic nerve damage (extending to involve the optic chiasm) can be a complication from the trauma with stretching and inflammation. ![]() The cornea undergoes rapid desiccation with malacia, and perforation is likely if not addressed promptly. Orbital hemorrhage can compound the globe luxation. It is usually associated with considerable head trauma, and often mandibular symphysis fractures are present. Proptosis or the traumatic displacement of the eye from the orbit is a serious disease in the cat ( Figure 14.2). (B) Symblepharon, or adhesion of the conjunctiva to the eyelids, the cornea, and to itself, in this kitten is obscuring visualization of a normal‐sized globe. The microphthalmia causes the exposure of the dorsal sclera within the palpebral fissure. Generally there is no treatment.įigure 14.1(A) Microphthalmia affecting both eyes in a kitten. Vision is usually present unless the cataract formation is advanced. Breeds affected include the Domestic Shorthair and Persian. Microphthalmia is a rare condition in kittens, but often these globes have multiple anomalies ( Figure 14.1).
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