Test Reviews Flashcards
If a rigid lens decenters off of the cornea:
A. gently massage the lens back to center through the lids
B. gently pop it off with a fingernail
C. place a finger directly on the lens and slide it back on
D. all of the above
All of the above
Post fit evaluations will show
A. Hypoxia
B. solution reactions
C. mechanical problems
D. all of the above
all of the above
On a compromised cornea, such as one that has undergone a corneal graft, what lens characteristic
would be most beneficial?
high Dk/t
On a true aspheric lens it is not possible to measure the …
Optical zone
When fitting soft contact lenses, one should aim to fit the _____lens possible that will provide adequate
coverage.
A. largest
B. flattest
C. smallest
D. steepest
Flattest
Poor GP insertion or recentering techniques may result in:
A. the lack of a fulcrum at 3 & 9 o’clock
B. 3 & 9 staining
C. arcuate staining
D. coalesced SPK
Arcuate Staining
Which of the following lens designs would most likely be used for correction of residual astigmatism?
A. spherical
B. bitoric
C. back toric
D. front toric
Front toric
Which of the following medications may affect successful contact lens wear?
a. Antacids
b. Antihistamines
c. Aspirin
d. Laxatives
Antihistamines
- The cornea receives nutrients from:
1) Aqueous humor
2) Tears
3) Limbal blood vessels
4) Orbicularis occuli
1) Aqueous humor
2) Tears
3) Limbal blood vessels
If the manufacturer’s guidelines suggest a minimum of 4 hours for disinfection, what would you suggest to the patient?
a) Never leave lenses in disinfectant overnight
b) 2 to 3 hours is probably enough
c) Use surfactant cleaner and preserved saline
d) A minimum of 4 hours is required
d) A minimum of 4 hours is required
- Which auxiliary trial lens will extend the keratometer to approximately 30.00 D?
a) +1.00 D
b) +1.25 D
c) -1.00 D
c)-1.00 D
- Which auxiliary trial lens will extend the keratometer to approximately 30.00 D?
a) +1.00 D
b) +1.25 D
c) -1.00 D
By placing a -1.00 D lens over the aperture of the keratometer, you can extend the low-end range from 36.00 D to
30.00 D.
The following is an example of what type of astigmatism? K’s 44.00 @ 180 / 44.50 @ 90
Rx -3.00 -2.50 x 180
a) Lenticular astigmatism
b) Against-the-rule astigmatism
c) Irregular astigmatism
d) Oblique astigmatism
Lenticular astigmatism
Lenticular astigmatism is present when there is significantly more astigmatism in the patient’s refraction (2.50 D) than
on their corneal surface (0.50 D). In this case, the astigmatism is not represented on the cornea and is most likely
found in the crystalline lens.
Ocular signs, of aging include:
1) Tear film abnormalities
2) Reduced lid elasticity
3) Lens opacities
4) Loss of accommodation
a) 1 only
b) 1 & 3
c) 2 & 4
d) All of the above
All of the above
Epithelium, Bowman’s membrane, Stroma, Descemet’s membrane, Endothelium
In alpha out
The normal cornea is transparent due to the pump action creating proper fluid balance. Which layer of the cornea
is most responsible for maintaining this function?
a) Endothelium
b) Basal membrane
c) Epithelium
d) Bowman’s membrane
Endothelium
A normal tear break up time is:
a) 6 –7 seconds
b) 10 – 12 seconds
c) Less than 5 seconds
d) None of the above
10-12 seconds
A whitish haze in the peripheral corneal stroma which does not stain and is often seen in the elderly is known as:
a) Neovascularization
b) Dellen
c) Arcus Senilus
d) Fuch’s Dystrophy
c) arcus senilus
- The following Rx represents: OD +2.00 = 20 / 20
OS -3.00 -2.00 x 180 = 20 / 20
a) Presbyopia
b) Anisometropia
c) Amblyopia
d) Emmetropia
anisometropia
The anisometropia patient will best achieve stereopsis with which of the following modalities?
a) Contact lenses
b) Spectacles
c) IOL
d) Scleral lenses
contact lenses
The keratometer is an instrument used to measure:
a) Corneal curvature
b) Lens power
c) Lens diameter
d) Lens thickness
Corneal curvature
An instrument used to evaluate corneal irregularity by reflecting concentric circles from the patient’s cornea is
called a:
a) Burton Lamp
b) Con-Ta-Chek
c) Topogometer
d) Placido Disk
Placido Disk
A Burton lamp evaluates fluorescein patterns in the absence of a slit lamp. A Con-Ta-Chek is an attachment to the
keratometer that enables one to read the base curve in the absence of a radiuscope.
A topogometer is also an attachment for the keratometer and is used to define the corneal apex
Which auxiliary trial lens will extend the keratometer to approximately 61.00 D?
a) -1.25 D
b) +1.25 D
c) -1.50 D
d) D.+1.50 D
+1.25 D
Wearing lenses in high attitudes and dry environments may result in complaints of all but the following:
a) Photophobia
b) Chalazion
c) Grittiness
d) Burning sensation
Chalazion
Patients with which of the following occupations can successfully wear contact lenses?
a) Arc welders
b) Firefighters
c) Teachers
d) All of the above
all of the above
Transient keratometric mire distortion is usually due to:
pre-ocular tear film
Irregular mires on a keratometer may be indicative of:
a) Dry eyes or excessive mucoid secretions
b) Keratoconus
c) Contact lens induced corneal warpage
d) All of the above
all of the above
Dry eyes with rapid tear film break-up time will cause the keratometer mires to blur and appear irregular soon after a
blink, as the tear film breaks up. Mucoid secretions will create an irregular surface on the cornea. Patients with
keratoconus have irregular astigmatism and therefore irregular mires, as do patients with contact lens induced corneal
warpage.
In an alignment lid attachment RGP fit, the fluorescein pattern should show:
A thin, even layer of fluorescein and less than 180 degrees of bearing in the mid-periphery
This allows for good tear exchange with each blink
In an RGP wearer, an arcuate stain on the cornea may be due to:
Poorly blended secondary curves
an RGP wearer has 3 and 9 o’clock staining because
failure to close the lids completely when blinking
An RGP lens fit excessively flat would cause…
Apical staining
What would usually cause a very fine, diffuse superficial punctate keratitis (SPK) from
limbus to limbus in an RGP wearer
Solution Sensitivity
In a Schirmer I test
A patient with an unanesthetized eye and normal tear output should wet at least 15 mm of the filter paper in
5 minutes
In a Schirmer II test:
An anesthetic drop is instilled before the Schirmer strip is inserted to eliminate the reflex tearing caused by the
filter paper
Rose Bengal test
Will stain devitalized conjunctival epithelial cells brightly
A patient wearing a high horizontal prismatic correction for a motility problem
May experience diplopia when fit with contact lenses
A pre-presbyopic myopic patient who is still able to read with single vision glasses may find that:
They are unable to see fine print when fit with contact lenses
Contact lenses require myopic patients to use more accommodation and convergence than spectacles. Patients who are
approaching presbyopia may find that their near vision is still adequate with glasses but cannot see small print when
fit with contact lenses.
Amy’s +8.50 D spectacles sit 12 mm from the cornea. The power of a soft contact lens for Amy, properly
vertexed, would be:
+9.50 D
Which of the following choices would work best for the patient’s visual needs, given the following information:
K’s 44.00 @ 180 / 45.25 @ 90
Rx -3.00 +0.25 x 90
Spherical soft lens
The patient’s refractive astigmatism is 0.25 diopters, which is essentially a spherical correction.
A soft spherical lens will correct this although corneal astigmatism is present
Which of the following set of lens specifications would best simulate an intrapalpebral RGP fitting given the
following information: K’s 42.00 @ 180 / 43.00 @ 90
Rx -2.00 -1.00 x 180
Upper lid positions 2 mm above the superior limbus
a) 42.50 -2-50 8.5
b) 42.00 -2.00 9.5
c) 41.50 -1.50 8.5
d) 41.50 -1.50 9.5
42.50 -2.50 8.5
An intrapalpebral fit is a small diameter, steep fitting lens designed to center between the upper
and lower eyelids. The other choices are either large diameter or flat fitting lenses.
Which contact lens would best correct this patient’s visual needs, given the following information:
K’s 46.00 @ 180 / 45.50 @ 90
Rx -3.00 -1.50 x 90
Soft toric lens
RGP lenses tend to decenter on against-the-rule corneas. There is not enough corneal toricity for an RGP lens with toric curves on the back surface to
stabilize.
