Contact Lens Exam 2

Front 1

In which contact lenses are infectious corneal ulcers more common?

Back 1

Soft

Front 2

What's the biggest disadvantage to RGP lenses?

Back 2

initial comfort

Front 3

T or F: environmental dust is an indication to use RGPs

Back 3

F! it's a disadvantage

Front 4

As oxygen permeability (Dk) increases, _____ decreases and is less stable.

Back 4

wettability

(traditional wisdom)

Front 5

PMMA lenses have all of the following except (1 answer):

good hardness, durability, optics, oxygen permeability, wettability

Back 5

they have poor Oxygen Permeability

Front 6

A teteracurve lens has how many zones outside of the OZD?

Back 6

3

a tricurve has 2 zones outside of the OZD

Front 7

When is back vertex power and front vertex power significant?

Back 7

plus lenses

Front 8

What does a v-gauge measure?

Back 8

OAD only

Front 9

What does the Contact lens identification kit use to identify the lens material?

Back 9

different solutions of different specific gravities

Front 10

What principle does the Radiuscope use to measure the BCR?

Back 10

Drysdale principle

measures the distance between the real and aerial images

Front 11

Which blend on RGPs has the most polishing?

Which blend on RGPs is assoc with discomfort and poort physiological response?

Back 11

heavy

light

Front 12

Which RGP edge shape is NOT associated with decreased comfort

Back 12

smooth or well-tapered (in the middle of the three)

Front 13

T or F: ideal edge is smoothyly tapered with apex 1/2 - 2/3 posterior

Back 13

T

Front 14

RGPs:

1. empirical or diagnostic fit better?
2. What's the average OAD?

Back 14

1. diagnostic
2. 9.20-9.50mm

Front 15

Would you fit a flat cornea with plus refractive error in a larger or smaller diameter RGP?

Back 15

larger

Front 16

What is better for RGP centration: WTR or ATR astigmatism?

Back 16

WTR

Front 17

If the patient has <= .50D corneal cyl, what Base curve should you start with?

Which corneal cyl amounts should you start "on K"?

Which corneal cyl amount should you do a bitoric or back toric design instead of spherical?

Back 17

0.50-0.75 FTK

1.25-1.50

>2.50

Front 18

The BCR is flatter/steeper for a lid attachment fit than for an interpalpebral fit.

Back 18

flatter

Front 19

T or F: it is better to use a viscous GP solution for evaluating fluorescein patterns than a soft multipurpose solution (on a RGP lens)

Back 19

F!!!

soft multipurpose and saline indicated

Front 20

What is another name for an alignment fit?

(what characteristic should it have)

Back 20

Minimal apical clearance

Front 21

T or F: there are three zones you need to pay attention to when evaluating fluorescein patterns

Back 21

T: central, mid-peripheral, peripheral

Front 22

If you have an over-refraction of >=____D, you need to vertex it before you add it to the diagnostic RGP power that you're trialing

Back 22

4.00D

Front 23

Which of the following are NOT considered minimum info for rigid lens ordering:

OZD, OAD, BCR, CT, power, material, color, PCS design, "dot" on OD or OS

Back 23

OZD, CT, PCS design, dot

Front 24

High oxygen demands (such as what two conditions) benefit from high/low Dk F-S/A materials.

Back 24

high plus lenses, sleeping in lenses

high

Front 25

T or F: coverage, centration and movement are three things to evaluate in an RGP fit

Back 25

F! no coverage!

centration, movement, fitting philosophy, NaFl pattern, fitting philosophy (LA, IP or modified LA)

Front 26

How much change is significant:

1. BCR
2. OAD
3. PCR
4. PCW

Back 26

1. .10 increments
2. .50 increments
3. 1.0 increments
4. .20 increments

Front 27

For a high minus spherical RGP, what edge is best?

Low minus?

Back 27

CN bevel and (+) lenticular

(-) lenticular

Front 28

T or F: soft contact lens solutions can be used with GPs, but GP solutions can't be used with soft contacts

Back 28

T

(scl absorbs everything and will absorb toxic chemicals)

Front 29

How are you supposed to clean RGP lenses?

Back 29

left-right action (not circular)

Front 30

F-S/A RGP: ___ deposit problems

SA: more likely to have ____ deposits

Back 30

High Dk F-S/A: lipid

SA: protein

Front 31

Boston Original does/doesn't have biguanide.

What "preservative" does Lobob Optimum use?

Back 31

doesn't

alcohol (not true preservative)

Front 32

Can Boston Simplus Multi action solution be used with high dk Menicon lenses?

How long do you have to store the RGPs in Lobob Optimum to disinfect?

Menicon progent is a ___ cleaner.

Back 32

yes (other boston's can't)

6 hours (boston's = 4 hours)

periodic (weekly)

Front 33

T or F: Walgreen's Daily Cleaner is approved for daily use in RGP lenses

Back 33

F! (used as extra-strength laboratory cleaner)

Front 34

If the patient experiences flare with RGPs, what's the solution?

Back 34

increase OZD (OAD) and improve centration

Front 35

If the patient has a low-riding lens and has a lid attachment fit, what should you do to the:

1. BCR
2. OAD
3. Mass/thickness of lens

Back 35

1. flatten
2. increase
3. decrease

Front 36

Lens adhesion with RGPs is due to flat/steep BCR, large/small OZD, or flat/steep PCR

Back 36

steep, large, steep

Front 37

___ cornea may decenter high or low

____ cornea may decenter temporal or nasal

Back 37

WTR

ATR

Front 38

____-based laboratory cleaners can be used to help "cure" lens surface dry spots/ poor wettability

Back 38

alcohol

Front 39

____-based solvents can cause crazing

Back 39

alcohol