Opthamology Flashcards
Define: Miosis
Small or constricted pupil
Define: Mydriasis
Dilated pupil
Define: Anisocoria
Different sized pupils (one pupil is larger or smaller than the other). May suggest trauma or neurologic disease
Define: Pupillary Light Reflex (PLR)
Pupils should constrict in light and dilate in dark
Define: Enucleation
Surgical eye removal (removing the globe)
Define: Proptosis
An eye that has popped out of the socket
Define: Hyphemia
Blood in the anterior chamber of the eye
Define: Hypopion
Pus in the anterior chamber of the eye
Define: Entropion
Rolling in of the eyelids
Define: Cherry eye
- Prolapsed gland of the third eyelid.
- The gland should never be removed surgically or dry eye will occur.
- The gland is typically replaced or “tacked down” surgically back under the third eyelid.
Define: Canthus
- Refers to the corner of the eye
- Medial canthus is the corner toward the nose
- Lateral canthus is the corner toward the ear
Define: Palpebrae
Proper name for eyelids
What is the orbit?
The hole in which the eye sits surrounded and formed by the maxilla, zygomatic, frontal, and ethmoid bones
What is the conjunctiva
- Membrane that lines the insides ofthe eyelids and eye itself
- It secretes mucus which helps to lubricate the eye
What is the function of the lacrimal gland
- To make tears which are secreted through the lacrimal duct
- It is also connected to the nasal passage via the nasolacrimal duct
What is the Third eyelid? Where is it located
- The Nictitating membrane.
- It is located near the medialcanthus and sometimes protrudes if the eye is painful, from trauma, or if the animal is sedated
Define: Sclera
White part of the eye
Define: Corena
3 facts
Forms the anterior part of the eye
- Clear and retracts light
- It has no vessels
- It is made up of 10 layers
Define: Uvea
What are the 3 parts that make it up + their function?
Definition: The vascular tunic
Made of:
1. The Choroid: Helps guard against glare
- Ciliary body: Helps to focus the eye
- Iris: The colored part of
the eye
Pupil:
- Location
- Function
- Location: central part of Iris
- Function: Light passes through it
Retina:
- Function
- Made of
- Made of: Rods and cones (mostly rods in dogs, which are best suited for night vision)
- Function: Forms images
Tapetum:
- Function
Reflective layer at the back of the eye which helps animals see in dim light
Fundus:
- Made of
- Location
Made of:
1. The optic disc (head of the optic nerve)
2. The neurosensory
3. Retina
4. Retinal pigment epithelium
5. Andchoroid
Location: Part of the posterior eye segment that is viewed with the ophthalmoscope
Lens:
- Define
- How do ciliary muscles play a roll in the lens?
A circular and transparent disc made of protein with no blood supply.
Ciliary Muscles: Moderates shape, helps with focus and distance
Define: Cataracts
Deposits on the lens
What are the 3 chambers of the eye?
- Anterior chamber
- Posterior chamber
- Vitreous
Where is the Anterior chamber located?
- What fluid does it have, and its function?
Between the front of the lens and cornea
Filled with aqueous humor (fluid) which is directly related to intraocular pressure
Where is the Posterior chamber located?
Between iris, lens, and ciliary body
Where is the Vitreous located?
- What fluid does it have, and its function?
Between the retina and iris
It has vitreous humor which has more of a jelly- like consistency instead of fluid to help keep the retina intact
What is the Schirmer Tear Test?
- Purpose
- How it works?
- Normal range?
Purpose: Tests tear production. Testing for Keratoconjunctivitis Sicca
(KCS).
- How it works: A small strip of designated STT paper is placed under the lower lid of each eye. The dye in the paper will begin to turn color as tears are produced
- Normal tear
production is greater than 15 mm in 60 seconds.
What is a Fluorescein Eye Stain?
- Purpose
- How it works?
- Test for a corneal ulcer or abrasion
- A small amount of yellow fluorescein stain is applied to the eyes
- If there is a
corneal defect or scratch, the dye will glow under a blue light
What is Tonometry
- What does it test for
- Normal values
- What do high/low values suggest
- Tonopen is used to measure intraocular pressures.
- Tests for glaucoma
- Normal pressures are less than 25 at less than 5% error. The reading should be taken 3 times or more to ensure accuracy.
- High pressures suggest glaucoma
- A low pressure suggests uveitis, or inflammation in the eye.
