Page 1214 - Problem-Based Feline Medicine

1206 PART 15 CAT WITH EYE PROBLEMS

Ocular larval migrans The degree of hemorrhage varies from focal areas of
Diagnosis is based on appearance of the suspicious blood in the vitreous or on the retina, to frank bleeding
fundoscopic lesions, or by observation of the parasite in throughout the vitreous and retina.
the anterior chamber. Severe cases may have a dilated pupil.

Vision loss will be determined by the extent of the
BLUNT OR PENETRATING TRAUMA* injury and the degree of hemorrhage within the eye.

Classical signs
● History of trauma to the head and/or eye. Diagnosis
● A focal or diffuse red coloration seen
Diagnosis is based on a history of trauma, and signs
through the pupil.
of hemorrhage in the eye.
● Varying degrees of vision loss will occur
depending on the severity of the injury. It is important to try to visualize the fundus, to deter-
● The conjunctiva and adnexal tissue may mine if there is detachment or tears of the retina.
show hemorrhage.
Ocular ultrasound is a very useful tool to determine
the state of the retina when it cannot be visualized
Clinical signs through the pupil. Retinal detachments are seen as
a bulging line away from the sclera. The integrity of the
When blunt or penetrating trauma causes retinal
scleral coat can be checked, and also the state of
hemorrhage, there is usually a history of trauma to the
the orbit behind the globe. In some cases the sclera may
head or eye, and a red appearance behind the pupil. The
be ruptured, and if this is the case, this will give a grave
conjunctiva and adnexal tissue may show hemorrhage.
prognosis for vision in an affected eye.
There may be hyphema causing diffuse redness of the
In severe ocular trauma, radiology of the orbit is indi-
anterior chamber, vitreal hemorrhage or retinal hem-
cated to check for fractures.
orrhage seen as a red eye through the pupil. The red
color through the pupil may be diffuse through the pos- CT scan and MRI are other tools that may be useful in
terior chamber (vitreal hemorrhage) or seen as retinal difficult cases. The shape, size and position of the globe
hemorrhage. When the red color is obvious, it is usually within the orbit can be compared to the other eye.
caused by hemorrhage from the retina into the vitreous. Orbital fractures can be demonstrated.

RECOMMENDED READING
Barnett KC. A Colour Atlas of Veterinary Ophthalmology. Wolfe Publishing Ltd, London, 1990.
Gelatt Kirk N (ed). Veterinary Ophthalmology, 2nd edn. Lea & Febiger, Philadelphia, 1991.
Gelatt Kirk N. Veterinary Ophthalmology, 3rd edn. Lippincott, Williams and Wilkins, Philadelphia, 1998.
Gelatt Kirk N. Essentials of Veterinary Ophthalmology. Lippincott Williams and Wilkins, Philadelphia, 2000.
Gelatt Kirk N. Colour Atlas of Veterinary Ophthalmology. Lippincott Williams and Wilkins, Philadelphia, 2001.
Gelatt Kirk N, Gelatt JP. Handbook of Small Animal Ophthalmic Surgery, Vol. 1 Extraocular Procedures. Permagon
Veterinary Handbook Series, Florida, 1994.
Gelatt Kirk N, Gelatt JP. Handbook of Small Animal Ophthalmic Surgery, Vol. 2. Intra-ocular Procedures. Permagon
Veterinary Handbook Series, Florida, 1995.
Ketring KL, Glaze MB. Atlas of Feline Ophthalmology. Trenton, NJ, Veterinary Learning Systems, 1994.
Peiffer RL, Petersen-Jones S. Small Animal Ophthalmology, A Problem Oriented Approach, 3rd edn. Saunders,
Philadelphia, 2001.