Test 30

1. The following wavelengths are correct:

a. nd:YAG   1,064nm 

b. blue-green argon   488nm 

c. green argon   532nm

d. diode laser   647nm

e. excimer laser   193nm
 

Answer

a.T   b.T   c.T   d.F   e.T
Krypton laser has a wavelength of 647nm whereas diode laser has a variable wavelength of between 780 - 850nm.

 
 

2. Lasers work in the following ways:
 

a. photodisruption

b. denature of protein

c. photocoagulation

d. breaking the molecular bond

e. photoablation
 

Answer
a. T   b.T   c.T   d.T   e.T
Photoablation breaks the molecular bonds. Photocoagulation causes denature of protein.

 

3. Induced hyperopia occurs in:

a. cystoid macular oedema

b. wearing of RGP lens

c. presbyopia

d. nuclear sclerosis

e. posterior dislocation of the lens

 
Answer
a.T   b.T   c.T   d.F   e.T
Nuclear sclerosis induces myopic shift. Wearing of RGP lens causes flattening of the cornea and hence hyperopia.
 
 

4. A chin up posture is seen in: 

a. double elevator palsy

b. bilateral sixth nerve palsy

c. Brown's syndrome

d. chronic progressive external ophthalmoplegia

e. A pattern exotropia
 

Answer
a.T   b.F   c.T   d.T   e.F
Bilateral sixth nerve palsy only affects the horizontal muscles. V pattern exotropia rather than A pattern exotropia causes chin up posture.

5. Kimsky reflex:

a. requires the use of a prism and a light source 

b. is used to estimate the amount of heterophoria

c. if on the pupil margin is equivalent to 30 prism dioptre

d. if between the pupil and the limbus is equivalent to 60 
    prism dioptre

e. if on the limbus is equivalent to 80 prism dioptre
 

Answer
a.F   b.F   c.T   d.T   e.T
Only a light source is needed. It estimates the amount of tropia.

 

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