Ophtalmic examination

Question 1

What is the general structure of an ophtalmic exam?

Answer 1

look at both globe and adnexa
in a specific order: outside to inside or eyelids to retina
examine both eyes: comparison, bilateral/symmetry, systemic diseases

Question 2

What are important questions to ask during hx of an ophtalmic exam?

Answer 2

signalment: breed, age, use/work, etc.
reason for consultation: change in appearance, change in behaviours, loss of vision, ocular pain
duration of signs, ocular discharge, redness, discomfort, rubbing, affect vision
systemic signs/disease

Question 3

What do we look at during the hands off ocular exam?

Answer 3

behaviour - vision
size and position of globes
asymmetry of eyes and face
signs of discomfort (blink rate, tears, rubbing, etc.)
abnormal eyelid or 3rd eyelid conformation
ocular discharge

Question 4

What are the main things to look at during hand on general ocular exam?

Answer 4

palpation and gentle retropulsion of globes
closer exam of adnexa
external exam of globe: conjunctive, episclera, cornea
palpebral reflex
menace response
vestibulo-ocular reflex

Question 5

What is the schirmer tear test 1 how do we perform it?

Answer 5

semiquantitative method of measuring aqueous portion of precorneal tear film

fold strip while packed, insert tip in lower conjunctival fornix
1 minute per eye

Question 6

What values are normal vs abnormal with an STT?

Answer 6

in dogs 15 and above = normal reading
10 and under = low reading
if unclear repeat at a later time

• dog in pain will tear more

Question 7

What is a focal light examination?

Answer 7

multiple tests: dazzle reflex, PLR, swinging light test, retroilumination

Question 8

What is the dazzle reflex?

Answer 8

partial blink reflex in response to light

Question 9

What is the PLR?

Answer 9

pupillary light reflex
both pupils should constrict when light is in 1 of them (non lighted less than lighted)

Question 10

What is the swinging light test?

Answer 10

in dim light swinging light from 1 pupil to another
consensual light reflex

Question 11

What is retroilumination?

Answer 11

shining light to see the tapetal reflection
looks at pupillary size, shape and symmetry, presence and opacity within the visual axis

Question 12

What is the palpebral reflex?

Answer 12

touch corners of the eyes for them to blink

Question 13

What is the menace response?

Answer 13

moving hand slowly towards the eye, should blink

Question 14

What is the vestibulo-ocular reflex?

Answer 14

head rotation causing opposite eye movement

Question 15

What is dyscoria?

Answer 15

when the pupil shape is abnormal for that species

Question 16

What is synechia?

Answer 16

When there is adhesion between tissues in the eyes where there shouldnt be

Question 17

What is anisocoria?

Answer 17

coria = pupil
asummetry in the pupil size

Question 18

What is mydriasis?

Answer 18

anisocoria where there is one large pupil

Question 19

What is miosis?

Answer 19

anisocoria where there is one small pupil

Question 20

How do we know if there is one larger pupil?

Answer 20

turn lights off
retroiluminate
if the pupil is already big, it can’t get bigger
but the normal pupil will dilate = the sizes of pupils will be more similar in the dark

Question 21

How do we know if there is one smaller pupil?

Answer 21

turn off lights
retroiluminate
normal/bigger pupil will increase in size
small pupil can’t change much
difference in sizes between the pupils will become much bigger

Question 22

How does retroilumination allow to test for an opacity within the visual axis?

Answer 22

any opacity will obstruct the passage of light towards the tapetum lucidum and will obscure the tapetal reflex
helps us locate the opacity
differentiates between cataracts and nuclear sclerosis

Question 23

What is hypaema?

Answer 23

blood within the anterior chamber
will block the light going towards the tapetum

Question 24

How can we tell if the opacity is in the anterior or posterior chamber of the eye?

Answer 24

When moving an opacity in the anterior chamber will move away from us
an opacity in the posterior chamber will move towards us
and opacity in thee middle will not move

Question 25

What is nuclear sclerosis?

Answer 25

normal aging change, isn't blinding lens nucleus becomes compacted with time causing a refractive change within the lens, a blue/gray appearance

Question 26

What is a cataract?

Answer 26

any true opacity within the lens potentially blinding

Question 27

What should we examine on the eyelids?

Answer 27

hairless eyelid margin different degrees of pigmentation meibomian gland openings

Question 28

What do we examine on the ocular surface?

Answer 28

variable pigmentation but minimal vascularisation visible purkinje reflexes

Question 29

What is the purkinje reflex?

Answer 29

reflecting light source on the eye's surface and looking for a sharp and smooth reflection vs a dull and disrupted one

Question 30

How do we describe the location of corneal and iris lesions?

Answer 30

using a clock dorsal/lateral/medial/ventral cornea: periphery/paraxial/axial iris: periphery/peripuilary/pupil

Question 31

What is hypopion?

Answer 31

pus in the anterior chamber

Question 32

What is keratic precipitates?

Answer 32

WBC in anterior chamber

Question 33

What is the tyndall effect?

Answer 33

looking if there is continuation of a light beam within the anterior chamber, indicating there is more than just water

Question 34

What condition can the tyndal effect help confirm?

Answer 34

uveitis

Question 35

What is tonometry?

Answer 35

estimation of the intraocular pressure (IOP) high: glaucoma low: uveitis

Question 36

What is the normal range of IOP for SA?

Answer 36

10-25 mmHg high variability between individuals, technique used, time of day difference should be less than 20% between both eyes

Question 37

What are topicamide eye drops?

Answer 37

dilate the pupil

Question 38

What is direct ophtalmoscopy?

Answer 38

provides direct upright image of the fundus 19.5x magnification, limited field of view has both positive and negative dioptre lenses distant: retroilumination/pupil close: retina

Question 39

What is indirect ophtalmoscopy?

Answer 39

virtual inverted slightly magnified image pupils need to be dilated monocular: no depth perception binocular: depth perception

Question 40

What is the sclera?

Answer 40

most posterior layer of the eye collagen and some blood vessels

Question 41

What is the choroid?

Answer 41

marked pigmentation layer, large blood vessels

Question 42

What is the tapetum?

Answer 42

very shiny surface of the choroid colour and size depends on the animal/eye

Question 43

What is the RPE retinal pigmented epithelium?

Answer 43

monolayer cells between choroid and retina heavy pigmented cells

Question 44

What is the retina?

Answer 44

most inner layer containing retinal vasculature continuous with the optic nerve thick but transparent

Question 45

What is a fluorescein stain?

Answer 45

to test for corneal ulcers rinse of with saline, examine surface with blue light

Question 46

What is a jones test?

Answer 46

fluorescein stain not rinsed monitor flow to the nose after 4+ min blue light reaches nose: no blockage doesn't reach nose: blocked, indication for flushing

Question 47

What is the seidel test?

Answer 47

fluorescein test to determine if there is perforation of the eye use cobalt blue light monitor for aqueous humour leaks

Question 48

When is a corneal/conjunctival cytology indicated for?

Answer 48

purulent conjunctivitis inflammatory infiltrate cornea melting ulcer careful in case of a fragile eye