Opthalmic Examination Flashcards
How should you broadly approach an ophthalmic examination?
Outside to inside
(Look at the orbits and facial symmetry, then go inside the eye and work back until you get to the retina and optic n
What is tonometry?
Measuring IOP
What is the normal IOP for a dog and cat?
15 - 20 mmHg
What key features should be obtained in the history for an ophthalmic exam?
Signalment
Reason for consult - change in appearance? Loss of vision? Ocular pain?
Duration of signs
Systemic signs of dz?
What should you do after the clinical history has been take?
Hands off examination
- facial symmetry
- size and position of eye
- watch them walking
- BCS estimate
- Discharge
- Abnormal eyelid or third eyelid?
When would you not perform retropulsion of the globes?
if a rupture is suspected
What do you expect to see from retropulsion of the globes?
Eyes should go back a little in the orbit as there is a fat pad which sits behind the eye
What should be performed during the hands on examination?
Palpation and gentle retropulsion Closer examination of the adnexa External examination of the globe - Conjunctiva and episclera + cornea Palpebral reflex Menace response Vestibulo-ocular reflex
What nerves does touching the medial and lateral canthus test?
MEDIAL - ophthalmic branch of CNV
LATERAL - maxillary branch of CNV
When should you perform the Schirmer tear test?
Why?
BEFORE you shine any light in the eye, manipulate the eye or apply topical solution
- shining light (etc) in the eye can make eyes water
What does the STT assess?
The reservoir of tears normally in the conjunctiva and the reflex production from mild corneal stimulation
What is the normal range for STT readings?
15mm/min + = normal
15-20
What can you assess using focal light examination?
Dazzle reflex, PLR, Swinging light test
Retro illumination - pupillary size and shape, Presence of opacity
Dark room - eyelids, ocular surface, iris, anterior chamber, lens
What is the dazzle reflex?
Shine light across eye
Blink and head turn
How should you position yourself for performing retro illumination?
Why?
At arms length, lower than the eye
So you can see the dorsal retina
- if not, see the non tapetal fundus which is black
What term is used to describe pupils of different sizes?
Anisocoria
What is Dyscoria?
Abnormal shape of the pupil
What can cause dyscoria?
Adhesions between the iris and the lens
How can you tell which pupil is abnormal when a patient presents with anisocoria?
An abnormally large pupil will make the anisocoria become LESS evident in the DARK as the other pupil dilates
An abnormally small pupil will make the anisocoria become MORE obvious in the DARK as abnormal pupil can’t dilate
What glands produce the tear film?
Meibomian glands
What is the role of tear film?
Helps maintain corneal clarity
What makes the cornea clear?
No BVs, pigment or myelinated nerves
How should light normally reflect from the eye?
Smooth reflection of light
What might a broken up, mottled reflection of light from the eye indicate?
Potentially dry surface
Where would you find an axial corneal lesion?
In the CENTRE
Where would you find a paraxial lesion in the cornea?
Between the centre and the periphery
What is Hyphaema?
Blood in the anterior chamber
What is hypopion?
WBCs in the anterior chamber
What are keratic precipitates?
Specks of debris on the corneal endothelium
What do keratic precipitates indicate?
chronic uveitis
What is the Tyndall effect?
How can this be assessed?
Aqueous flare
Focal light examination - no gap in light beam as it passes through anterior chamber
(Should be gap)
What diagnostic value does tonometry have?
IOP changes in:
Glaucoma
Uveitis
Keratitis, conjunctivitis, scleritis and orbital cellulitis
What components of the fundus should you look for?
Optic n. Retinal vasculature/ tapetum Tapeto- non tapetal junction Non tapetal fundus Periphery fundus
What is the difference between direct and indirect opthalmoscopy?
Direct: - just using the scope -
Upright image of the fundus
Limited but detailed field of view
Indirect: - looking through a lens -
Virtual Inverted
Pupils need to be dilated
What is the Jones test?
Apply fluorescein
Wait for around 4 mins
If dye can be seen in nose, nasolacrimal duct isn’t blocked (look with UV)
