CL 2-5: GP Modification Lecture Flashcards
Lens Modification Techniques
- 7 Things that can be modified..
- OAD reduction
- Secondary/Peripheral Curve FABRICATION
- Edge/and Surface Polishing
- Lens Repowering
- Blending
- CN Bevel
Modification: What can be done for each of the situations:
- Lens Awareness
- Dryness or Fluctuating Vision
- Insufficient Lens Movement with the Blink
- Decreased VA with Spherical O/R
- Simple Edge Polish
- Surface Polishing
- Blend or Flatten Peripheral Curves
- Re-Power the Lens
Advantages to Modification
- Is it quick and easy to Perform?
a. Who can do it? - Does it save time and chair money?
- Increase Pt Satisfaction: Why?
- Yes
a. Trained Techs - Yes
- Don’t have to wait for lens re-order, wearing schedule not interrupted, instant improvement in vision/Comfort, Appreciated service to the patient.
When would Modification NOT be Helpful?
- What situations?
- If what changes are NEEDED?
- If pt does what to their lens?
- Complex situations…where you don’t feel confident in re-performing the modification
- multiple parameter changes are needed
- can you remake it the same way again
Disadvantages to Modification
- Risk Factors (3)
- What is needed to do this?
- Break Lens, Lose Lens, Ruin Lens Optics
2. Advanced techniques require skill and practice
What Lens Parameters can you Modify in your office?
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- OAD
- OZD
- Flatten 2ndary Curve Radius and width
- Flatten Peripheral Curve Radius and Width
- Increase a Blend
- Edge Contour, Finish, Thickness
- Surface Finish
- Lens Power, if changing +0.50 DS to -0.75 DS from current lens power
- Truncation
Parameters you CANT Modify In-Office ?
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- BC
- Steepening any peripheral, secondary, or intermediate Curve Radii and Widths
- Power changes past +0.50DS to -0.75 DS
- CT
- Decreasing a Blend
- Increase OAD or OZD
- ANY Lens made of MENICON Z or other HIGH-Dk material (polishing is OKAY THOUGH)
- Any lens that’s PLASMA TREATED
- Any surface that’s Toric, Aspheric, or contains a multifocal
What 3 Steps should be taken when doing lens Modification?
- Verify Lens Parameters
a. Power/BC/PC/SC/IC widths/ Edge configuration/ CT/ Optical Clarity - Perform Modification
- Re-Check Lens Parameters
Instruments to Verify Parameters
- BCR? (3)
- Power?
a. Which side do you measure? - Center Thickness?
- 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?
- Lenscometer, Radiuscope, or Rediusgauge
- Lensometer
a. The CONCAVE SIDE! - Thickness Gauge
- 7x or 10x Measuring Reticule
a. Shadowscope and Hand Magnifier (7X)
b. V-Channel Guage
Parameter Tolerances
- BC
- BC-Warp
- CL Power
- OAD
- OZD
- CT
- Edge
- Surface Quality
- Tint
- Optical Quality
- +/- 0.25 D (0.05 mm)
- +/- 0.37 D (0.07 mm)
- +/- 0.25 D
- +/- 0.1 mm
- +/- 0.1 mm
- +/- 0.1 mm
- accurate
- Look for scratches/chips/ markings/ color/ intensity
- Color/intensity
- Distortion/Wavy Images
What are the main tools needed for Modification? (9)
- Modification Unit
- Water Bowl
- Suction Cup (“GREENIE”) or Spinner
- Sponge Tools
- Radius Tools (Brass, Plastic, or Delrin-Type)
- Anterior Bevel Cone Tool
- Tool Covering/Materials (velveteen, tape, baby blanket)
- GP Lens polish and water
- reticle Magnifier (7x or 10x)
Table Top Units
a. 2 Parts to them…
- Modification Unit should have what?
- a. Bowl that should be cleaned (soap and water) after each use
and a Motor
- a Spindle and the Water Bowl
DMV Stronghold Suction Cup
- What’s the FLAT end used for?
- What’s the CONCAVE end used for?
- We can place this tool into what?
- What else is needed during the process?
- Attach to the BACK surface of the GP
- attach to the FRONT surface of the GP
- Into a SPINNER TOOL
- Water and Polish
Sponge Tools
- 2 types of FLAT Sponge tools?
- What other Sponge tools are there?
- 3 inch or 1 inch
2. a Cone and a Hollow Sponge Tool
Radius and Cone Tools
- 4 Types
a. Each are Available in what mm Steps?
- Brass (Radius
- Plastic
- Delrin (Conforma) (Radius and Sponge)
- Diamond (Cut-down Cone, Radius)
a. 0.2 to 0.3 mm steps
Brass Radius Tools
- They have a smooth/rough surface?
- Do they have to be covered with anything? If so, what?
- SMOOTH
- YES. A Soft Material
Silk Tape
Baby Blanket
Velveteen
Moleskin
Diamond Radius Tools
- Do they have a Smooth/Rough Surface?
a. What is on it?
- ROUGH
a. the Rough surface is FINE DIAMOND DUST IMPREGNATED into the tools surface
Radius & Cone Tools
- WHAT MUST BE DONE WITH THESE SURFACES?!
- THEY HAVE TO STAY WET!