Test 22

1. The following can be used to reliably measure the thickness of 
     the retinal nerve fibres:

a. scanning laser polarimetry

b. Heidenberg retinal tomography

c. B-scan ultrasound

d. MRI scan

e. optical coherence tomography
 

Answer
a. T   b.T   c.F   d.F   e.T
Scanning laser polarimetry (SLP), Heidenberg retinal tomography (HRT) and optical coherence tomography (OCT) can be used to measure the thickness of the retinal nerve fibres and monitor glaucoma patients.

2. The advantages of automated perimetry over the manual 
    perimetry include:

a. the results can be subjected to statistical analysis

b. both static and kinetic perimetry can be performed

c. a larger visual field can be tested

d. no technician is needed

e. the blind spot can be tested
 

Answer
a.T   b.F   c.F   d.F   e.F
Both automated and manual perimetries can be used to perform static and kinetic perimetry. The manual perimetry such as Goldmann perimetry can test a larger visual field than the automated perimetry which typically tests the central 30 degrees. Technicians are needed for both tests.

3. Optic nerve drusen can be identified with:

a. monochromatic blue light

b. MRI scan

c. CT scan

d. plain X-ray

e. ultrasound

Answer
a.T   b.F  c.T   d.F   e.T
MRI scan does not show the calcification well. 
Plain X-ray does not give enough resolution to 
show the calcification. 
Monochromatic blue light can reveal autofluorescence.

4. Features of optic neuritis include:

a. central scotoma

b. colour defect

c. invariable decrease of visual acuity

d. relative afferent pupillary defect

e. optic disc pallor in the early stage
 

Answer
a.T   b.T   c.F   d.T   e.F
Visual acuity may be normal. Optic disc pallor is 
a late sign. In optic neuritis, the optic disc may be 
normal if the lesion is retrobulbar or swollen if the optic nerve head is involved.
 

5. The following situations will give rise to a falsely high intraocular 
    pressure with applanation tonometry:

a. corneal oedema

b. post LASIK

c. Sturge-Weber's syndrome

d. too much fluorescence dye

e. high myopia

 
Answer
a.T   b.F   c.F   d.T   e.F
A thicker cornea than normal will give a falsely high intraocular pressure. To much fluorescence increases the thickness of the half circle and can give a falsely high pressure when the two circles overlap.

 

More MCQs