EQUINE OCULAR EXAMINATION(first lecture)

Question 1

First 3 things to do equine ocular exam?

Answer 1

I. History
II. Brief general examination
III. Ocular examination

Question 2

Describe the 4 ocular examination?

Answer 2

1. Head+adnexa (inspection, palpation)
2. Preliminary exams
    dPLR / iPLR (pupillary light reflex)
    STT (Schirmer Tear Test)
    Sample taking
    Visual tests
3. Detailed ocular exam in dark
   Anterior+posterior segment
4. Additional exams

Question 3

History?

Answer 3

PPE, claim for compensation, syst dx

Question 4

Brief general examination?

Answer 4

Temp, HR, RR, lymphnodes, MMs
syst. dx  ocular sign, neurological investigation!

Question 5

Ocular examination?

Answer 5

1. Head+adnexa (inspection, palpation)
   symmetry, scar, pain
   globe size, movement, position
   eyelids, conjunctiva, eyelashes
   blepharospasm
   en-/exophthalmos
   lacrimation/discharge

Question 6

?

Answer 6

Phtisis bulbi

Question 7

Answer 7

Ventromedial deviation of the bulb

Question 8

Answer 8

Prominent nicitans

Question 9

Answer 9

Eyelid sarcoid

Question 10

Preliminary exams?

Answer 10

dPLR (iPLR if pupil is not visible)
Afferent: retinaoptic n.chiasmaoptic tract
80% optic tractnucl. geniculatus lat.visual cortex
20% optic tractnucl. pretectalis n. oculomot. parasimp. nucl.
Efferens: EW parasimp. nucl. ganglion ciliare (orbita)
m. sphincter pupillae
d/iPLR, anisocoria, dyscoria, polycoria

Question 11

Name 12 Cranial nerves?

Answer 11

CN I. Olfactory Oh
CN II. Optic Oh
CN III. Oculomotor Oh
CN IV. Trochlear To
CN V. Trigeminal Touch
CN VI. Abducent And
CN VII. Facial Feel
CN VIII. Vestibulocochlear Virgin
CN IX. Glossopharyngeal Girls
CN X. Vagus Vaginas
CN XI. Accessory And
CN XII. Hypoglossal Hymens

Question 12

Describe what occurs during blinking?

Answer 12

Blinking due to bright light (twinkle)
Afferent: CN IIrostral colliculus (retino-collicular reflex)
Efferent: CN VII eyelid muscles (squinting, blink)
Subcortical reflex (midbrain-hypothalamus )+other:
vestibulo-, audio-, eye movement reflex
Not in the cortex, not a visual test!

Question 13

What are the 4 neurons of the impulse conduction?

Answer 13

1. rods+cones;
2. bipol cells;
3. ganglion cells;
4. CGL neurons

Question 14

describe the Menance response?

Answer 14

Menace response
Within some days after birth (horse).
Afferent: retina  CN II visual cortex
Efferent: CN VII eyelid muscles
Retino-geniculo-cortical projection
If menace is absent, test eyelid reflex!

Question 15

Describe the eyelid reflex?

Answer 15

Eyelid reflex:
Afferent: periorbital skin  CN V  brainstem
Efferent: CN VII  eyelid muscles

Question 16

Describe the Maze test?

Answer 16

Visual tests
Maze test
In light, in dark (photopic, scotopic)
1 eye blindfolded (monocular)
Through obstacles, labyrinth

Question 17

Name and describe visual tests/ reflexes?

Answer 17

Reflexes, visual tests

• eyelid reflex
  (aff: skin trigeminal n.brainstem, eff: facial n.)
• dazzle reflex
  (aff: optic n.dors. colliculus, eff: facial n.)
• menace
  (aff: optic n. visual cortex, eff: facial n.)
• maze test

Question 18

?

Answer 18

Tonometry

Rebound-TonoVet
Applanation-Tonopen

(cornea surface)

Question 19

Describe Tonometry?

Answer 19

electronic (Tono-pen, TonoVet)
IOP normal: 17-28 mmHg,
difference bw OU 5 mmHg
Affect:- sedation (xylazine 25% )
- blepharospasm
- auriculopalp. n. block
- corneal pathology
- time of day
- head position

Question 20

Why do we take sampling from horse eye?

Answer 20

bacteriological, fungal culture

• smear: cytology, fungus?
• biopsy
• corneal ulcer, conjunctiva, eyelid
• topical anesthesia +/-
• evaluation: normal flora!

Question 21

Describe the detailed ocular examination in dark?

Answer 21

Sedation+ analgesia: 2 recepror agonists
Topical an.: proparacain / oxibuprocain eyedrops
Auriculopalpebral n. block
(n. facialis, motor block, orbicular oculi m.)

Question 22

Instruments used for ocular examination?

Answer 22

Portable slit lamp biomicroscope
Finoff transilluminator
Direct ophthalmoscope
Indirerct ophthalmoscope
Panoptic

Question 23

Answer 23

. Detailed ocular exam in dark
Anterior segment
Cornea, limbus: pectinate ligament insertion
(gray line medial/lateral),
medially wider
linear keratopathy

Question 24

A, B C?

Answer 24

A Focal illumination

B Indirect illumination

C Retro illumination

Question 25

Answer 25

KPs

wbc and fibrin accumulates inner part cornea

Question 26

Describe the anterior chamber?

Answer 26

Anterior chamber

• turbid AH – protein content (aqueous flare)
• WBC  hypopion
• blood  hyphema

Question 27

Direct focal illumination?