Presentacion

EXOPHTHALMOS IN VETERINARY MEDICINE: THE DIAGNOSIS AND MANAGEMENT OF RETROBULBAR DISEASE EXOFTALMÍA EN MEDICINA VETERINARIA: DIAGNÓSTICO Y TRATAMIENTO DE LA ENFERMEDAD RETRO BULBAR
Ron Ofri DVM, PhD, Diplomate ECVO. Associate Professor in Veterinary Ophthalmology. Koret School of Veterinary Medicine. Hebrew University of Jerusalem. Israel

Exophthalmos can be defined as a normal eye that ispushed forward in the orbit due to a space occupying retrobulbar (orbital) disease (Figure 1). The presentation of exophthalmos can be quite dramatic and distressing. In some cases it is acute and very painful. Other cases may be accompanied by signs of general malaise or neurological disease. In cases of extreme exophthalmos the eyelids can not close over the eye, resulting in corneal exposure andkeratitis, or possible ulceration or perforation. The aim of this paper is to provide the clinician with guidelines for the diagnosis and management of the exophthalmic patient.

La exoftalmía se puede definir como un ojo normal que se protruye hacia adelante de la órbita debido a la invasión de ese espacio por enfermedad retro-bulbar (orbital) (Figura 1). La presentación de la exoftalmía puedeser absolutamente dramática y angustiante. Es, en algunos casos, aguda y muy dolorosa. En otros casos, puede acompañarse por malestar general o enfermedad neurológica. En casos de exoftalmía extrema los párpados no pueden cerrarse sobre el ojo, resultando en queratitis corneana, con posible ulceración y perforación. El objetivo de esta publicación es proveer al clínico de las pautas para eldiagnóstico y manejo del paciente exoftálmico.

Figure 1 A dog with exophthalmos due to a retrobulbar abscess caused by a foreign body. Swelling of periorbital tissue and protrusion of the third eyelid are evident Figura 1 Canino con exoftalmos debido a absceso retrobulbar causado por un cuerpo extraño. Son evidentes la hinchazón del tejido periorbital y la protrusión del tercer párpado.DIFFERENTIAL DIAGNOSIS The most common causes of exophthalmos are retrobulbar abscess/cellulitis and retrobulbar neoplasia. Together with retrobulbar traumatic hematoma, they account for more than 90 percent of all exophthalmos cases. There are a number of other causes for the presentation, including myositis of the extraocular muscles, and salivary cysts/mucoceles. However, as these are less common, theirworkup and management will not be discussed in this paper. It is worthwhile noting that some clinicians may be confused between exophthalmos and buphthalmos. The latter is a globe that is enlarged due to elevation in intraocular pressure (i.e., glaucoma), but one that is situated normally in the orbit. However, despite differences in globe size, globe position and causes, clinicians may find itdifficult to differentiate between the two syndromes, as both present with an asymmetric appearance of the globe. A number of tests can be used to distinguish exophthalmos from buphthalmos. The easiest is probably to evaluate the patient’s orbit from the side or above to detect the forward displacement of the globe in exophthalmos. Estimating the corneal curvature, which is increased in buphthalmos,is also an easilyperformed test and a reliable indicator. However, ultimate differentiation between exophthalmos and buphthalmos relies on measurement of intraocular pressure, or ultrasound/CT imaging of a retrobulbar disease process.

DIAGNÓSTICO DIFERENCIAL Las causas más comunes de la exoftalmía son absceso/inflamación y neoplasia retro bulbar. Junto con el hematoma traumático retro bulbar,explican el 90 por ciento de todos los casos de exoftalmía. Hay un número de otras causas para la exoftalmia, incluyendo la miositis de los músculos extra oculares y quistes/mucoceles salivales. Sin embargo, como éstos son menos comunes, no los trataremos en este informe. Vale la pena observar que algunos clínicos pueden estar confundidos entre exoftalmía y buftalmos. Este último representa un...