Test 100   (eye miscellaneous)

1. In a normal eye, the following will increase intraocular pressure:

a. respiratory obstruction

b. hypoxia

c. atropine

d. hypercarbia

e. phenylephrine

Answera.F   b.T  c.F  d.T  e.F
Unless the patient has shallow angle, atropine and phenylephrine do not increase the intraocular pressure.
Hypoxia, hypercarbia, raised blood pressure and 
increased venous pressure can cause raised intraocular pressure in normal patients.

2. Retrobulbar block causes:

a. decreased lacrimation

b. papilloedema

c. raised intraocular pressure

d. proptosis

e. mydriasis

Answera.F   b.F   c.T   d.T  e.F
Increased volume in the retrobulbar space increases the intraocular pressure and proptosis.

3. The following structures are blocked by retrobulbar anaesthesia:

a. short ciliary nerve

b. abducent nerve

c. facial nerve

d. mandibular nerve

e. oculomotor nerve

Answera.T   b.T  c.F  d.F  e.T
Facial nerve and mandibular nerve are not found in the retrobulbar space.

4. Lesion of the trigeminal nerve causes:

a. decreased blinking

b. decreased corneal sensation

c. lower lid ectropion

d. decreased reflex tear production

e. mydriasis

Answera.T  b.T  c.F  d.T  e.F
The trigeminal nerve is involved in the blink reflex and corneal sensation.
Reflex tear production is reduced if the corneal sensation is impaired.

5. True statements about toxocariasis include:

a. it is caused by a protozoan

b. the pathogen lives in the intestines of dogs

c. human contracts the disease through ingesting the eggs

d. most patients are less than six years of age

c. bilateral ocular involvement is common in ocular 
    toxocariasis

Answera.F  b.T  c.T  d.T  e.F
It is caused by a nematode T. Canis. The natural host 
includes the dogs and foxes where it lives in the intestines. Excretion of eggs in the faeces by dogs and ingesting of 
eggs by human is the most common form of transmission. 
Ocular involvement is uncommon and even rarer is bilateral involvement.

 
 

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