![]() ![]() Earlier surgical removal of prolapsed third eyelid gland (cherry eye) can predispose to later KCS. KCS can occur uni-or bilaterally, and is most often due to an immunologic reaction in the tear glands, but can also be connected with systemic disease and occur as a drug-related reaction (especially sulphonamides). Although KCS can be seen in dogs of any breed, there is a certain breed predisposition. Keratoconjunctivitis sicca is caused by lowered or absence of tear fluid. Based on the primary cause, topical steroids may be added. Chalazion is treated by curettage followed by topical antibiotics. Neoplasms of the eyelid should be resected surgically through a wedge-shaped incision and submitted for histopathology. Chalazion is a granuloma formation at the rim of the eyelid caused by retained meibomian secretions and may be associated with chronic blepharitis. An important differential diagnosis to tumors of the eyelid is chalazion. In general, tumors of the upper eyelid produce most obvious clinical signs, as the upper eyelid is more involved in blinking and the third eyelid helps in protecting the cornea from tumors on the lower eyelid. A benignant: malignant ratio of 3:1 has been reported for eyelid tumors. Tumors of glandular origin (adenoma or adenocarcinoma) are most common, followed by melanomas. Severe pain may cause enophthalmos and miosis and is an important differential diagnosis to Horner's syndrome.Įyelid neoplasms occur most frequently in older dogs, with a mean age of 9-10 years. The result may, however, be difficult to interpret. The level of injury can be diagnosed medically, by observing the time until pupil dilation after instillation of topical epinephrine. A thorough examination to identify the primary cause is indicated. Idiopathic Horner's syndrome occurs in middle aged and old dogs with a breed predisposition in the Golden Retriever. In the dog, some sympathetic fibers may also innervate the smooth muscles in the eyelids and periorbita.Ĭlinical signs in Horner's syndrome include enophthalmos and drooping of eyelids (ptosis), in addition to miosis due to lack of tone in the extraocular smooth muscles. From here the pupillomotor fibers enter the cavernous sinus and join the trigeminal nerve, pass through periorbita and enter the globe via the long ciliary nerve. Within the middle ear the sympathetic fibres join a branch of the glossopharyngeal nerve and cross the middle ear. At the level of T1 to T3 the nerve leaves the spinal cord, extends along the thoracic sympathetic trunk and synapses in the cranial cervical ganglion near the tympanic bulla. The sympathetic nerve fibres arise from the hypothalamus, pass through the brainstem and follow the cervical spinal cord to synapse with preganglionic cell bodies in the gray matter. Horner's syndrome is caused by an affection of the sympathetic nerve. In most breeds a congenital malformation of the drainage angle is present (goniodysgenesis) with further clogging of the angel with age. Several breeds may be affected, including the American Cocker Spaniel, Basset Hounds, Samoyed, Welsh and English Springer Spaniels, Bouvier des Flandres, Siberian Husky and Norwegian Elkhound. Primary glaucoma is a breed related disease, with bilateral clinical manifestation occurring in middle aged to older dogs. Examination of the oral cavity should always be performed in dogs with space-occupying orbital lesions. Orbital ultrasound is useful in diagnosis, preferably combined with a fine-needle aspirate. In contrast, in glaucoma the globe itself is enlarged and the increase in intraocular pressure is usually more significant, the exception being concurrent uveitis where the intraocular pressure may be reduced even in buphthalmic eyes. Venous compression may lead to slightly elevated intraocular pressure in neoplasia-induced exophthalmos. Exophthalmos caused by orbital neoplasia must be distinguished from buphthalmos caused by glaucoma. Neoplasms are not initially painful, in contrast to orbital inflammatory disease. Lateral deviation is most frequent, most often with a concurrent protrusion of the third eyelid. Unless the tumor is positioned straight behind the globe, a deviation of the eye may be noted. Orbital neoplasms cause slowly progressive exophthalmos. In comparison, orbital abscesses most commonly occur at a younger age, with a mean age of about 4 years. Orbital neoplasms in general occur in older animals, the mean age being approximately 9.5 years. Thus, it is important to identify and treat underlying conditions if present, and a general examination should always be included in the work-up of an ocular condition. Ocular disease in the aging dog may be divided into primary ocular disease, and ocular signs of systemic disease. The animals' quality of life relies in part on our skills in identifying and treating these conditions. Older animals may suffer from ocular conditions that may be of slight discomfort, painful or vision threatening. ![]()
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