Ophthalmic Examination Flashcards
Systemic conditions of the eye usually present…..
bilaterally
What is important to take note of in a Hands off Ophthalmic Examination? (5)
Behaviour- Vision, blink rate
Size and position of globe
Asymmetry
Ocular Discharge
Eyelid conformation
What are the three main reflexes tested in a hands on examination?
Palpebral reflex
Menace response
Vestibulo-ocular reflex
What does the Schirmer test do?
measuring aqueous portion of precorneal tear film- dry eye
What is classed as a normal reading in a Schirmer test?
What is abnormal?
15mm/min and above are normal
10mm/min and less is abnormal
What is tested during a focal light examination? (3)
Dazzle Reflex
PLR (pupillary light reflex)
Swinging Light Test
What structure does Retroillumination illuminate (lol)?
Tapetum Lucidium causes a green illumination behind the eye (like a mirror)
What does Retroillumination aim to examine?
- Pupil Shape
- Pupil Size & Symmetry
- Presence of Opacity
What is dyscoria?
abnormal pupil shape- can be due to trauma, masses etc.
What is aniscoria?
asymmetry in pupil size
What is the difference between Mydriasis and Miosis?
Mydriasis- large pupil
Miosis- small pupil
In the dark, with an abnormally large pupil…
the aniscoria becomes less obvious
In the dark, with an abnormally small pupil…
the aniscoria becomes more obvious
How does Retroillumination help detect opacities?
any opacity will obstruct the passage of light towards the tapetum lucidum and will obscure the tapetal reflex- we can use this to help us locate the opacity
What is Hyphaema?
blood in the anterior chamber
An opacity in the posterior segment of the eye….
moves in the same direction as the examiner
What is the difference between cataracts and nuclear sclerosis?
Nuclear Sclerosis- normal aging change where the lens nucleus becomes compacted with time to cause a blue/grey appearance on the lens- does not cause visual impairement
Cataracts is a true opacity in the lens that is potentially blinding
What is the Tyndall effect?
Aqueous fluid in the anterior chamber is usually clear- when there are proteins present inside the fluid, the light may reflect in multiple directions, leading to the scattering of light. This is called the Tyndall effect and shows the presence of inflammatory cells in the fluid.
What is Tonometry?
estimation of intraocular pressure
What are the three different methods of Tonometry?
- Indentation
- Applanation
- Rebound
What is the normal IOP of an animal?
10-25mmHg (varies between individuals and between eyes but shouldn’t have more than 20% difference)
What is Tropicamide?
eye drops to dilate the pupil
What is the difference in the views of Direct and Indirect Ophthalmoscopy?
Direct- upright (but limited) field of view of the fundus
Indirect- virtual, inverted and magnified (bigger field of view)
What is needed to be done before performing Indirect ophthalmoscopy?
pupils need to be dilated
How does monocular and binocular indirect ophthalmoscopy differ?
Include advantages/ disadvantages.
Monocular- lens is held by examiner- no depth perception but has a low cost
Binocular- lens is positioned on a headband , larger depth perception but equipment can be very expensive to purchase
What is Fluorescein stain used for?
To examine corneal ulcers
Jones Test- blockages in the lacrimal system
Seidal Test- uses cobalt blue light to monitor for aqueous humour leaks
When would you perform corneal/ conjunctival cytology?
Purulent Conjunctivitis
Melting Ulcers
Inflammatory infiltrates in the cornea
