Ophthalmic examination in horses

Question 1

What is the Granula iridica

Answer 1

• Cap to protect eye on pupil

Question 2

How is distant direct ophthalmoscopy carried out?

Answer 2

• Lens set on 0
• Arms length
• Opacities appear as dark silhouettes against bright tapetum

Question 3

How is close direct ophthalmoscopy carried out?

Answer 3

• 2-3cm from eye
• 0 to -3D = Fundus
• +2D to +6D = vitreous
• +7D to +8D = lens
• +10D = cornea

Question 4

What ocular reflexes should be examined? When?

Answer 4

• BEFORE SEDATION
• PLR - direct + indirect
• Dazzle reflex
• Menace response
• Palpebral reflex
• Corneal reflex

Question 5

What nerve blocks can you give to examine the eye?

Answer 5

• Auriculopalpebral nerve block
• Frontal nerve block - if upper eyelid painful

Question 6

What are other techniques to assess the eye?

Answer 6

• Tonometry
• Ocular ultrasound
• CT + MRI
• Electro-retinography (ERG)