CL 2-5: GP Modification Lecture Flashcards Preview

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Flashcards in CL 2-5: GP Modification Lecture Deck (45):
1

Lens Modification Techniques

1. 7 Things that can be modified..

1. OAD reduction

2. Secondary/Peripheral Curve FABRICATION

3. Edge/and Surface Polishing

4. Lens Repowering

5. Blending

6. CN Bevel

2

Modification: What can be done for each of the situations:

1. Lens Awareness

2. Dryness or Fluctuating Vision

3. Insufficient Lens Movement with the Blink

4. Decreased VA with Spherical O/R

1. Simple Edge Polish

2. Surface Polishing

3. Blend or Flatten Peripheral Curves

4. Re-Power the Lens

3

Advantages to Modification

1. Is it quick and easy to Perform?
a. Who can do it?

2. Does it save time and chair money?

3. Increase Pt Satisfaction: Why?

1. Yes
a. Trained Techs

2. Yes

3. Don't have to wait for lens re-order, wearing schedule not interrupted, instant improvement in vision/Comfort, Appreciated service to the patient.

4

When would Modification NOT be Helpful?

1. What situations?

2. If what changes are NEEDED?

3. If pt does what to their lens?

1. Complex situations...where you don't feel confident in re-performing the modification

2. multiple parameter changes are needed

3. can you remake it the same way again

5

Disadvantages to Modification

1. Risk Factors (3)

2. What is needed to do this?

1. Break Lens, Lose Lens, Ruin Lens Optics

2. Advanced techniques require skill and practice

6

What Lens Parameters can you Modify in your office?

(9)

1. OAD

2. OZD

3. Flatten 2ndary Curve Radius and width

4. Flatten Peripheral Curve Radius and Width

5. Increase a Blend

6. Edge Contour, Finish, Thickness

7. Surface Finish

8. Lens Power, if changing +0.50 DS to -0.75 DS from current lens power

9. Truncation

7

Parameters you CANT Modify In-Office ?

(11)

1. BC

2. Steepening any peripheral, secondary, or intermediate Curve Radii and Widths

3. Power changes past +0.50DS to -0.75 DS

4. CT

5. Decreasing a Blend

6. Increase OAD or OZD

7. ANY Lens made of MENICON Z or other HIGH-Dk material (polishing is OKAY THOUGH)

8. Any lens that's PLASMA TREATED

9. Any surface that's Toric, Aspheric, or contains a multifocal

8

What 3 Steps should be taken when doing lens Modification?

1. Verify Lens Parameters
a. Power/BC/PC/SC/IC widths/ Edge configuration/ CT/ Optical Clarity

2. Perform Modification

3. Re-Check Lens Parameters

9

Instruments to Verify Parameters

1. BCR? (3)

2. Power?
a. Which side do you measure?

3. Center Thickness?

4. OAD/OZD/PCW/SCW/ICW/Edge Contour of the CL?
a. What 2 things can be used for Edge Contours?
b. What else can be used for OAD measuring?

1. Lenscometer, Radiuscope, or Rediusgauge

2. Lensometer
a. The CONCAVE SIDE!

3. Thickness Gauge

4. 7x or 10x Measuring Reticule
a. Shadowscope and Hand Magnifier (7X)

b. V-Channel Guage

10

Parameter Tolerances

1. BC

2. BC-Warp

3. CL Power

4. OAD

5. OZD

6. CT

7. Edge

8. Surface Quality

9. Tint

10. Optical Quality

1. +/- 0.25 D (0.05 mm)

2. +/- 0.37 D (0.07 mm)

3. +/- 0.25 D

4. +/- 0.1 mm

5. +/- 0.1 mm

6. +/- 0.1 mm

7. accurate

8. Look for scratches/chips/ markings/ color/ intensity

9. Color/intensity

10. Distortion/Wavy Images

11

What are the main tools needed for Modification? (9)

1. Modification Unit

2. Water Bowl

3. Suction Cup ("GREENIE") or Spinner

4. Sponge Tools

5. Radius Tools (Brass, Plastic, or Delrin-Type)

6. Anterior Bevel Cone Tool

7. Tool Covering/Materials (velveteen, tape, baby blanket)

8. GP Lens polish and water

9. reticle Magnifier (7x or 10x)

12

Table Top Units
a. 2 Parts to them...

2. Modification Unit should have what?

1. a. Bowl that should be cleaned (soap and water) after each use

and a Motor

2. a Spindle and the Water Bowl

13

DMV Stronghold Suction Cup

1. What's the FLAT end used for?

2. What's the CONCAVE end used for?

3. We can place this tool into what?

4. What else is needed during the process?

1. Attach to the BACK surface of the GP

2. attach to the FRONT surface of the GP

3. Into a SPINNER TOOL

4. Water and Polish

14

Sponge Tools

1. 2 types of FLAT Sponge tools?

2. What other Sponge tools are there?

1. 3 inch or 1 inch

2. a Cone and a Hollow Sponge Tool

15

Radius and Cone Tools

1. 4 Types

a. Each are Available in what mm Steps?

1. Brass (Radius

2. Plastic

3. Delrin (Conforma) (Radius and Sponge)

4. Diamond (Cut-down Cone, Radius)


a. 0.2 to 0.3 mm steps

16

Brass Radius Tools

1. They have a smooth/rough surface?

2. Do they have to be covered with anything? If so, what?

1. SMOOTH

2. YES. A Soft Material

Silk Tape

Baby Blanket

Velveteen

Moleskin

17

Diamond Radius Tools

1. Do they have a Smooth/Rough Surface?

a. What is on it?

1. ROUGH

a. the Rough surface is FINE DIAMOND DUST IMPREGNATED into the tools surface

18

Radius & Cone Tools

1. WHAT MUST BE DONE WITH THESE SURFACES?!

1. THEY HAVE TO STAY WET!

19

Radius & Cone Tools

1. Diamond Impregnated tools are KEPT WET with WHAT?

2. What about Polishing Sponges and Pads?

3. Failure to do these things will do what?

1. with WATER ONLY

2. First with WATER, then Thoroughly saturated with POLISH

3. Allows too much heat to build and can DAMAGE the Lens surface

20

Tool Covering Materials

1. The more COARSE/HARD the modification tool, or the material covering it, the MORE it will do what to a CL?

2. From Hardest to softest, what are the materials/tools? (7)

1. the Faster it will MODIFY (or ruin) a CL.

2. Diamond > Brass > Tape > Velveteen > Moleskin > Baby Blanket > Sponge

21

Tool Covering Materials

1. They have to BE COMPENSATED when choosing a Radius:

a. Velveteen Pads

b. Surgical Tape

c. Moleskin

d. Baby Blanket

2. Thickness of a Material MUST be added/subtracted to know the true radius to be applied?

1. a. 0.4 mm Thick

b. 0.2 mm Thick

c. 0.625 mm thick

d. 0.275 mm thick

2. ADDED!

22

Polish (1)

1. Polish Brands Specifically Made for GPs (6)

2. Forms: 2 Types

1. a. Alox
b. Boston Polish
c. Polish Brite
d. Polysheen
e. SilO2 Care
f. X-Pal

2. a. Pre-mixed

b. Powder (mixed w/Distilled H2O)
i. Some use GP Conditioning Solution: Leads to INCREASED Viscosity and Stays on Tools Longer

23

Polish (2)

1. Suspension of Fine, Abrasive Particles in Solution (4)

2. Applying Polish to Tools
a. When is it Applied?
b. What 2 things does Polish Prevent?

1. a. Aluminum Oxide
b. Coolants
c. Surface Wetting Enhancers
d. Suspending Agents

2. a. While the Tool is Rotating

b. Prevents Damage to the Motor, AND Prevents Liquid from Seeping Down into the Spindle

24

What are 4 Potential Problems of having a Lens De-centered on the Suction cup?

1. Oval OZD

2. Uneven Edge Polish

3. Uneven Surface Polish

4. Compromised Lens Optics

25

Diameter Reduction

1. What 2 tools could be used?

a. OAD of the TOOL should be how much LARGER than the Final desired OAD?

b. Leaves material for what 2 things?

1. Conical Abrasive tool or Diamond Impregnated Tool

a. 0.2 mm larger than final desired OAD

b. For finishing and Polishing lens Edge

26

Peripheral Curve Application

1. Attach the Lens to a Suction Cup: Which side should be out? (Convex or Concave)?

2. Choose Appropriate Radius tool and Attach what to it?

3. Turn on the Motor and Wet the Tool Head with what?

4. How should the Lens be held?

5. Hold the lens Vertical to the Radius tool and rotate it how?

6. After how many seconds should you add polish and rotate the greenie?

7. Check lens with what and verify what?

1. CONCAVE side out

2. a Soft Material Pad or Tape

3. with WATER, then APPLY POLISH (Reapply polish throughout the process)

4. Lightly against the Tool with the CONCAVE surface facing the tool

5. in a Figure 8 Design

6. Every 5 Seconds

7. with Reticle Magnifier. Verify WIDTH and QUALITY of the Curve you're applying, and clean lens thoroughly prior to viewing w/the magnifier

27

Blending Curves

1. Unblended Junctions
a. What do they do to Tear Exchange?
b. Are they Comfortable?

2. Blended Junctions
a. What 2 things happen?

1. a. Inhibit it.
b. No. Cause Discomfort

2. a. Promote Tear Exchange and Increase Lens movement

28

Blending Curves

1. Tool Selection
a. Radius should be HALFWAY b/w that of what?

b. If the Optic Zone Junction is to be Blended, you should NEVER select a tool that's what...?
i. Why? (2 things)

1. a. halfway b/w that of the 2 curves to be blended

b. that's LESS than the BCR of the Lens

i. BC could WARP, and BC could quickly FLATTEN

**REVIEW SLIDE 73!!

29

Blends

1. Light
a. Time of Blend?
b. Transition Zone?

2. Medium
a. Time of Blend?
b. Transition Zone?

3. Heavy
a. Time of Blend?
b. Transition Zone?

1. a. 5 Seconds
b. Transition Zone is EASILY seen with a MEASURING MAGNIFIER

2. a. 10 Seconds
b. It's seen, but SHADOWS start forming at PERIPHERAL JUNCTIONS

3. a. 15-20 seconds
b. only seen as SHADOWS; Measurement of Curve Widths is VERY DIFFICULT and can only be estimated by MEASURING SHADOWS

30

Edge Polish

1. What tool is used?

a. What happens if we use incorrect polish techniques on this tool?

1. Sponge tool with CENTRAL HOLE

a. It can ALTER LENS POWER!

31

Front Surface Polish (1)

1. What tool is used?

a. What 2 types of polishes can be done?

1. Flat Sponge Tool

a. Mid-Peripheral to Peripheral Front Surface polish

and

Center Front Surface Polish

32

Front Surface Polish (2)

1. Mid-Peripheral to Peripheral Polish

a. Attach and center lens on a Suction Cup w/Convex/Concave side out?

b. Wet the flat sponge tool first with what?

c. Apply what to the rotating sponge thruout the procedure?

d. Place the lens halfway b/w what?

e. Hold the lens at what Angle for Mid-peripheral?

f. Hold the lens at what angle for Peripheral?

g. When doing this procedure, you should CONTINUOUSLY do what?

h. Depress the lens into the sponge how far and for how long?

1. a. CONVEX

b. with WATER thoroughly and place it on the spindle

c. Polish

d. b/w the Center and Edge of the Sponge

e. 60-degree angle

f. 45 degree angle

g. Rotate the lens in the OPPOSITE direction of rotation of the tool

h. about 1/8 of an inch for 10-15 seconds

33

Front Surface Polish (3)

1. Center Polish

a. Hold the suction cup how to the sponge?

b. Depress the Lens in and out of the Sponge center how many times?

c. The Lens should be in contact w/the sponge for how long each time to prevent optical distortion or power changes?

1. a. PERPENDICULAR

b. 10-12 times

c. for Only 1 Second at a time

34

Edges

1. +

2. Knife

3. A-Cut

4. Round

5. Butt

6. V-cut

1. Apex of a Plus lens is biased toward the back surface of the lens and shows a thin, smooth apex

2. edge is very sharp and Excessively thinned at the lens edge apex

3. when a lens is placed Concave up in a 90 degree cutdown tool, this is the resultant edge

4. round lens edge is bulky and round w/the majority of the edge mass sitting in the middle of the edge profile

5. an unfinished, uncut lens w/a blunt flat edge

6. lens is placed CONCAVE down in a 90 degree cutdown tool, this is the resultant edge

35

Back Surface Polish

1. What tool is used?

2. Mont the lens on a suction cup Convex/Concave side out?

3. Moisten Cone Sponge w/what?

4. Add what frequently thru the procedure while the spindle is rotating?

5. Place the lens where?

6. Depress the lens into the sponge how far and rotate how?

7. Then do what?

1. Cone-shaped Sponge Tool

2. CONCAVE

3. Water and place on spindle

4. Polish

5. just off of the center of the sponge

6. 1/8-inch; Rotate Opposite the Spindle Rotation for 10 to 15 seconds

7. Inspect the lens and repeat the procedure if necessary

36

Lens Re-Powering: Minus

1. SUCTION CUP + FLAT SPONGE METHOD

a. Mount and center the lens Convex/Concave side out on a suction cup?

b. Place the Flat sponge tool (covered with what) on the spindle, wet it thoroughly w/water and polish

c. Place the lens how far from what?

d. The lens must be held how to the tool surface at ALL TIMES?

e. Apply what pressure?

f. What should be added to the surface of the tool during the procedure?

g. After HOW MANY ROTATIONS do you CHECK the Power to get an idea how fast the power is changing?

h. 1-4 ROTATIONS normally will add what?

i. The limit of minus power addition with this method is what? Why?

1. a. CONVEX

b. Covered with BABY BLANKET or VELVETEEN

c. about 1 inch from the Peripheral Edge of the Spinning Sponge

d. PERPENDICULAR

e. Light pressure and revolve the lens around the tool opposite the rotation of the tool (maintain lens about 1 inch from the PERIPHERAL EDGE)

f. Polish

g. 1 ROTATION

h. -0.50 D to the lens

i. -0.75D due to risk of Optical Distortion

37

Lens Re-Powering: Minus (2)

1. SPINNER + ROUND SPONGE TOOL METHOD

a. Why would this method be more advantageous?

1. a. More MINUS power can be added w/o causing optical distortion (1D to 2D) as opposed to the Flat Sponge Method

38

Lens Re-Powering: Plus

1. FLAT DRUM TOOL and SUCTION CUP

a. Cover the Sponge tool with what?

b. Wet tool surface w/water and add what?

c. Lens is Convex/Concave side out on the suction cup?

d. How should it be placed in contact with the tool?

e. Using MILD PRESSURE, lens is rotated how?

1. a. Velveteen or Baby Blanket

b. Polish to the rotating tool frequently during the procedure

c. CONVEX

d. placed at the Center of the Drum tool in a PERPENDICULAR orientation

e. BOTH Clockwise and Counterclockwise

39

CN Bevel

1. Edge design?

2. Form of what?

3. Easy for Lab to manufacture using what tools?

4. Usually Rxed starting at what power?

5. Prevents what?

6. When is F1 COUNTOURING DONE?

a. How is it done?

1. Anterior tapered edge design

2. of Plus Lenticular

3. using Cone Tools

4. starting at -5.00 D Power

5. Prevents aggressive lid attachment in HIGH MINUS LENSES

6. when the CL is TOO THICK, which CAUSES DISCOMFORT and POOR EDGING

a. A VELVETEEN PAD or TAPE is placed w/in a BRASS CONE TOOL to create the CN BEVEL

40

Fenestration

1. What is it?
a. What 3 THINGS does it PROVIDE?

2. Some LARGER OAD Trial LENS SETS Arrive how?

1. SMALL HOLE Drilled thru GP Lens

a. IMPROVE Tear Exchange, Improve O2/Gas Exchange, Decrease Suction

2. arrive already FENESTRATED

41

In-Office Fenestration

1. Hole Formed with what?

2. Fenestration Opening is what?

3. Opening is Polished with Felt tipped cone tool and what?

4. Performed on what?

1. with 1 mm HAND-Held Drill Bit (carefully)

2. is BEVELED

3. and COPIOUS AMTS of POLISH

4. on BOTH SIDES of the LENS

42

Truncation

1. What portion of the Lens is removed?
a. About how much?

2. Lens stabilizes via alignment of what?

3. Common in translating what?

1. INFERIOR PORTION
a. 0.5-1.5 mm

2. of Thicker edge w/lower lid margin

3. GP Multifocal Designs

43

To LOOSEN a Tight Lens

1. What 2 things can you REDUCE?

2. What 2 things can you FLATTEN?

3. What can you Widen?

4. What can you INCREASE?

1. Optic Zone and OAD

2. BC and Peripheral Curves

3. Peripheral Curves

4. the Blend b/w the Peripheral Curves

*All of these Can be done IN OFFICE EXCEPT for Flattening the BC!

44

To Tighten a Loose Lens

1. What 2 things can you increase?

2. What 2 things can you Steepen?

3. What can you reduce?

4. What about Blend?

1. Optic Zone and OAD

2. BC and Peripheral Curves

3. Width of the Peripheral Curves

4. Order No Blend

45

Modification Bottom Line

1. GP Patients will what?

2. ROI for modification is GOOD!
a. New equipment cost?

b. Can charge how much per polish?

c. Can polish Lenses how many times a year?

d. Can save yourself from what?

1. EXPECT you to perform this service for them

2. a.