A variety of external or intraocular conditions may be responsible. Excessive lacrimation results from irritation to the eye. The clinical signs include a milky, watery discharge and a crusting of the facial hair near the medial corner (canthus) of the eye. Important ocular disorders of the rabbit include epiphora, conjunctivitis, blepharitis, uveitis, and glaucoma.Įpipora is either caused by excessive tearing or inadequate tear drainage. They are often scared and reluctant to move in the examination room. Vision assessment in rabbits can be difficult. Topical anesthesia and dilating agents can be used to facilitate the examination. This means behind the eye there is a mass of veins important to note when contemplating removing the eye (enucleation).Įxamination of the eye by your veterinarian may include a Schirmer tear test (checking tear production quantity), a fluorescein stain test (checks for corneal ulcers and NL duct patency), and tonometry (measurement of eye pressure). To visualize the optic disc, your veterinarian must look up, rather than straight back into the eye with instruments.Ħ. An extensive orbital venous plexus. Another species variation of the rabbit is the location of the optic disc. This is called a holoangiotic retina.ĥ. The optic disc is known for having abundant myelination (myelin is analogous to insulation around an electrical wire). Dogs and cats have blood vessels throughout the retina. This would be a species variation from the dog and cat that your veterinarian would take note of on examination. This muscle is not visible in the human, dog, cat.Ĥ. Retinal blood vessels which are present only medially and laterally to the optic nerve head (disc). This muscle is responsible for rotating the eye upward. The NL duct drains tears from the eye into the nose/mouth.ģ. A visible dorsal (superior) extraocular (rectus) muscle through the dorsal (top) conjunctiva. This punctum is the opening to a tortuous nasolacrimal (NL) duct of variable diameter. These glands contribute to the tear filmĢ. A single, large, inferior nasolacrimal punctum opening. These are called the lacrimal, gland of the nictitating membrane (third eyelid), Harderian gland, and intraorbital gland. normal variation) include the following:ġ. Four orbital glands within the orbit. Anatomical ophthalmic features unique to the rabbit (i.e. The eyelids open in the rabbit about 10 days after birth. This gives the albino rabbit a normal, reddish reflection from within the eye. Albino rabbits lack pigment in their iris and choroids. The rabbit also has the following basic mammalian eyeball structures: iris, pupil, lens, ciliary body, vitreous, choroid, and retina. The cornea is clear so light can enter the eye and a visual image can be formed. The cornea is the clear continuation of the fibrous sclera. Compared to some species, such as man, the rabbit sclera is not very visible. The sclera gives the globe shape and has the very important job of protecting the intraocular contents. ![]() ![]() The sclera is the fibrous, white outer layer of the globe. The conjunctiva is a vascular, protective tissue that lines the eyelids and the sclera. The upper, lower, and third (nictitans) eyelids protect the eyeball, particularly the cornea. The extraocular muscles on the surface of the eye are responsible for eye movement. The orbit typically does a superb job of protecting the eye. The orbit is made of numerous bones and soft tissue structures (fat, glands, muscle). The eyeball (globe) is housed within the orbit. The more common etiologies (causes) of eye problems in the rabbit include nutritional deficiencies, infections, environmental and management problems, genetic influences, and congenital malformations. ![]() These ophthalmic conditions are often different than eye diseases of the dog, cat, or other pet rodents. Pet rabbits may experience a variety of ophthalmic diseases.
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