Week1- Approach to the investigation and Diagnosis of eye disease

Question 1

What is the function of mydriatic drops?

Answer 1

Dilates the pupil

Question 2

What is the function of nasalocrimal cannulae?

Answer 2

Used for flushing

Question 3

Name 5 bits of equipment that could be used in an opthamology exam

Answer 3

Direct opthalmoscope
Finhoff transilluminator
Converging lens
Tonovet/ Tonopen

Question 4

Name 5 consumables you might use in an opthalmic exam

Answer 4

1. Schirmer tear test
2. Mydriatics
3. Nasolacrimal duct cannula
4. Topical anaesthetic
5. Opthalmic dyes

Question 5

What is a goniolens?

Answer 5

Used to view drainage areas (iridocorneal angle)
any abnormalities that lead to glaucoma

Question 6

What is a binocular opthalmoscope used for?

Answer 6

Allows you to look at both eyes

Question 7

What is the palpebral fissure?

Answer 7

The space between the upper and lower eyelids

Question 8

What might you do during an external eye assesment

Answer 8

Gentle palpation of periorbital strcutures and bony orbit
* assess eyelids, conjunctiva and third eyelid
* note ocular discharge
assess the cornea and tear film

Question 9

What is the purkinjie reflex?

Answer 9

Refers to the light that is usually reflected off the eyes optical structures

Question 10

What is the schirmer tear test 1?

Answer 10

• Place the tear test strip in the fornix for 60 seconds
  measures reflex production of the aqueous component of the tear film

Question 11

What are the indications of the schirmer tear test 1 in dogs?

Answer 11

• Less than 5 = KCS
  5-10= suspicious if combined with clinical signs

Question 12

What are the indications of the schirmer tear test 1 in cats?

Answer 12

Variable, low readings must be interpreted with clinical signs

Question 13

What is Schirmer tear test 2 measured with?

Answer 13

usually measured with local anaesthesia applied- goes on to measure the basal tear production

animal cant feel so there is no additional tear production

Question 14

What eye disease are cats usually prone to?

Answer 14

Melanoma

Question 15

What is the function of tonometry?

Answer 15

Measures the intraocular pressure of the eye

Question 16

What is the function of a tonopen?

Answer 16

• local anaesthetic is needed
  applanation tonometry measures the force required to flatten an area of the cornea

Question 17

What is a tonovet?

Answer 17

Rebound tonometry measures the time for a small probe to propel and contact the cornea before rebounding to the instrument

Question 18

What is a schiotz tonometer?

Answer 18

Indentation tonometry measures the amount of corneal indentation produced by a given weight

Question 19

Why should you not put mydriatics in if the animal has glaucoma?

Answer 19

Pupil dilation decreases the drainage angle

Question 20

How much pupil dilation is required to complete an opthalmic examination?

Answer 20

Tropicamide 1%
(wait 20 minutes)

Question 21

What is lens luxation?

Answer 21

When the lens becomes dislocated from its original position

Question 22

What is the difference between indirect and direct opthalmoscopy?

Answer 22

Direct Ophthalmoscopy is best for detailed central retina examination, especially in clinics where quick checks are needed.

Indirect Ophthalmoscopy is superior for viewing the peripheral retina, detecting retinal detachments, hemorrhages, or tumors.

Indirect ophthalmoscopy is commonly performed with a head-mounted binocular device or a handheld lens.

Question 23

How would you do a corneoconjunctival culture?

Answer 23

• Roll a sterile swab on the corneal lesion or lower conjunctival sac
• place in the correct transport medium

Question 24

How would you do a corneoconjunctival cytology?

Answer 24

• Remove excess mucus before sampling
• Gently scrape conjunctiva with the blunt end of the scalpel blade or cytobrush
• If concerns over a corneal lesion, use a mini-tip swab

Question 25

What is fluorescein dye most commonly used for?

Answer 25

* Used to detect corneal ulceration * attaches to the exposed stroma as it is hydrophillic * Lipophobic so will not adhere to the corneal or conjunctival epithelium * Fluoresces more clearly using cobalt blue filter on direct opthalmoscope

Question 26

Name 4 **other ** uses of fluorescein

Answer 26

1. Detect conjunctival epithelial defects 2. To detect aqueous fluid leakage 3. Qualitatively test the tear film 4. assess nasalocrimal drainage

Question 27

What is rose bengal usually used for?

Answer 27

* Used to diagnose tear film disorders Useful for certain types of ulceration that dont stain as clearly with fluorescein * hepatic keratitis * Punctate keratitis * Preocular tear film disorders

Question 28

How would you perform a nasalocrimal flush?

Answer 28

* Cannulate the upper punctum and slowly irrigate with 3-5ml sterile saline * confirm patency of puncta and caniculi with fluid exiting from the lower punctum * Occlude the lower puncta and confirm patency of the nasalocrimal duct with fluid exiting from the ipsilateral nostril *cats may need sedation due to having small puncta*

Question 29

What are the indications for ocular imaging?

Answer 29

* eyelid or periocular swelling opacity of cornea, anterior chamber, lens or vitreous suspected trauma or foreign body

Question 30

What are the indications for orbital imaging?

Answer 30

* Exopthalmos * Strabismus * Suspected trauma or foreign body Periorbital disease Facial swelling or distortion