Possible MCQ questions Flashcards
When were the first silicon hydrogel lenses launched?
1998
The Dk of a soft, non-silicone hydrogel contact lens with 55% water content is approx?
18
Dymed TM
a) is highly toxic
b) low molecular weight
c) low absorption into lens matrix
d) all of the above
has low absoprtion into lens matrix
A NaFl pattern under an RGP lens shows little NaFl along the horizontal meridian and more along the vertical meridian, especially towards the periphery. This pattern most likely represents a
a) flat, spherical RGP on a WTR toric cornea
b) steep, spherical RGP on an ATR cornea
c) back surface toric RGP fit on Ks of a WTR cornea
d) front surface toric RGP on a spherical cornea
flat, spherical RGP on a WTR toric cornea
The main reason to fit a toric, back surface, rigid lens in the case of an astigmatic cornea is
a) to improve vision
b) to improve fit
c) to allow lens flexure
d) none of the above
to improve fit
In general, ATR corneal astigmatism frequently creates problems with
a) poor lateral centration
b) poor vertical centration
c) lens falling out
d) difficulty with lens removal
poor lateral centration
The optimum lens of choice for a patient with spx Rx of -3.00DS with corneal astigmatism of -1.50 x 180 is
a) aspheric RGP
b) RGP with toric peripheral curves
c) spherical SCL
d) back surface toric RGP
a rigid gas permeable lens with toric peripheral curves
A patient complains of flare at night when driving with his RGPs. His -5.00 lenses are positioned 2.5mm superior temporal in BE. Which of the following combinations will best alleviate his symptoms?
a) flatten BC and increase TD
b) steepen BC and increase OZD
c) flatten BC and decrease OZD
d) steepen BC and decrease TD
steepen BC and increase OZD
Toric secondary peripheral RGPs are
a) toric in the front optic zone only
b) toric in the peripheral curves only
c) toric in the back optic zone and peripheral curves
d) toric in the back optic zone and spherical peripheral curves
toric in the peripheral curves only
A common characteristic of steep fitting RGP is
a) minimal vertical movement
b) central apical staining
c) lateral decentration
d) mid peripheral clearance
minimal vertical movement (?)
Dellen formation is commonly found
a) central cornea
b) peripheral cornea
c) nasal conj
d) temp conj
peripheral cornea
What is the conversion factor for a +1.25 and -1.00 respectively for extending the range of a keratometer
1.166 and 0.8575
Px complains lens is popping off. What is the least likely cause for his problem?
a) high edge lift
b) upper-lid attachment fitting
c) small TD
d) small OZD
upper-lid attachment fitting (?)
3 and 9 o’clock staining can be improved by increasing
a) Dk of material
b) lens diameter
c) wetting angle of material
d) edge thickness of lens
lens diameter
Which of the following factors puts an eye at the greatest risk of microbial keratitis?
a) poor compliance/hygiene
b) swimming with no goggles
c) no hand washing
d) overnight wear CL with insufficient oxygen permeability
d) overnight wear of CLs
