Ophthalmology

Question 1

Actions of the oculomotor nerve

Answer 1

Elevation
Depression
Adduction
Extorsion

Question 2

Actions of the superior oblique

Answer 2

Intorsion (in primary positon)

Depression (when adducted)

Question 3

Actions of the lateral rectus

Answer 3

Abduction

Question 4

Ductions

Answer 4

The range of movement of each eye

Question 5

Versions

Answer 5

Conjugate movements of both eyes

Question 6

Principles of diplopia analysis

Answer 6

1. Images will spread out as the eyes move in the direction of pull of the weak eye muscle
2. The more peripheral image is from the eye with the weak muscle

Question 7

CN III palsy

Answer 7

Ex: aneurysm (PCA/SCA), trauma, neoplasm
Sx:
-Eye is down and out
-Large blown pupil
-ptosis

Question 8

CN IV Palsy

Answer 8

Ex: Head trauma (long course so easily disrupted)
Sx: Difficulty with intorsion and depression
Head tilt to unaffected side

Question 9

CN VI Palsy

Answer 9

Ex: microvascular (DM), Increased ICP stretches, neoplasm (cavernous sinus), trauma
Sx: difficulty with eye abduction, head turn to realign eyes

Question 10

One and a half syndrome

Answer 10

Lesion of CN 6 and MLF
Results in ability to abduct the unaffected side eye
Lose all other horizontal movements

Question 11

Red flags for tearing in a child

Answer 11

1. No mucopurulence
2. Light sensitivity
3. Cloudy corneas

Question 12

Nasolacrimal Duct defects

Answer 12

Congenital obstruction of nasolacrimal duct
Sx: tearing, mucopurulence
Tx: clean lids and lashes, massage
Most spontaneously resolve around 1 year

Question 13

Abnormal visual behaviour in a child

Answer 13

Delayed social smile
Poor eye contact
Nystagmus age <4 mo
Increased light sensitivity
Staring at bright lights
Pressing on eyes

Question 14

Three catogories of amblyopia causes

Answer 14

1. Poor clarity- retinal image transmission
2. Poor focus- refractive errors
3. Poor aim- strabismus