CL 2-4: GP Fitting 2

Question 1

Before Putting a Lens on:

1. What do you look for?
   a. What do you use to inspect the lens?

Answer 1

1. Surface Quality; Any Scratches or Breaks

a. Reticle Magnifier

Question 2

Before Putting the Lens on

1. CLEAN and CONDITION!
   a. Two-Bottle System (Do what 3 steps)
   b. 1 Step System (what 2 steps)
   c. Oxidative System (What 2 steps)

Answer 2

1. a. Rub, Saline Rinse, Condition
   b. Rub, Rinse and Condition, all with the Same solution
   c. Rub, Rinse and Neutralize

Question 3

Cause of Non-Wetting Lens

1. Why does the lens become non-wetting?
   a. This requires the use of 1 of 2 things?

Answer 3

1. Due to CURVE CUTTING AND Polishing being done w/Lathe
   a. use of PITCH or SOFT WAX
   i. Pitch = Vegetable Tar Product (Leaves Residue)

Question 4

Lid Position and Fitting Goal

1. Upper Lid Position Relative to Superior Limbus
   a. Above
   b. At
   c. Below

Answer 4

1. a. Fit smaller lens (Goal: Interpalpebral Fit)
   b. Same as (a.)
   c. Fit Larger Lens (Goal: LID Attached Fit)

Question 5

Time of Centration Assessment

1. When do you look at it?
   a. Part of what kind of Assessment?
   b. Should you hold the Lids?
   c. Is Fluorescein Needed to assess it?

Answer 5

1. Where lid rests B/W BLINKS
   a. Dynamic Assessment
   b. NO
   c. NO

Question 6

What’s Acceptable for Centration

3 things to ask yourself

Answer 6

1. Is Pt Comfortable
2. Is Pt complaining of Haloes and GLARE (is pupil w/in Optic Zone)
3. Is lens causing any Physiological changes to the Cornea (NaFl STAIN)

Question 7

Assessing Fit

1. What 4 things do we assess?

Answer 7

1. Lens-Lid Relationship
2. Centration
3. Movement
4. Fitting Relationship

Question 8

GP Movement

1. What does it promote?
   a. What does it provide?
   b. What does it remove?

Answer 8

1. Post-lens tear film exchange and Mixing
   a. O2
   b. Waste Products

Question 9

GP Movement

1. Quantified as Vertical/Horizontal Change in Lens Position during a NORMAL blink?
2. Think about size of the lens relative to the size of the Cornea to gauge your movement in millimeters. What is ACCEPTABLE?
3. Which GP lens will MOVE LESS: Flat or STEEP?

Answer 9

1. VERTICAL CHANGE
2. 1-2 mm
3. STEEP Fitting GP will MOVE LESS than a FLAT fitting GP (just like soft lenses)

Question 10

More About movement

1. Watch pattern of movement: If ARCUATE MOVEMENT (S Shaped movement) is OBSERVED, or if LENS DROPS QUICKLY, lens may be what kind of FIT?
2. What 2 other things can also affect movement?

Answer 10

1. LOOSE/Fitting Flat
2. Lacrimation (can cause a ton of movement) and Lens Thickness (Really High Center THICKNESS, it will just DROP down, causing lens to sit on a lower eyelid…you can order a thinner center thickness to fix this)

Question 11

Lens Movement over Time

1. GPs will Tighten/Loosen with wear time?

Answer 11

1. Tighten (due to Post-lens tear film thins and Movement Slows)
   * F/U’s are Important!

Question 12

Insufficient Lens Movement

1. When is Vision best?
2. What kind of lenses may “BIND” to the eye over time?
3. What type of lenses MAY BE COMFORTABLE?

Answer 12

1. Just after a BLINK and worst just before a blink (Opposite for Lenses with EXCESSIVE MOVEMENT)
2. TIGHT/STEEP LENSES
3. TIGHT LENSES
   * Loose/Flat lenses tend to move a lot and are usually not comfortable

Question 13

Assessing the Fit

1. White Light used to assess what 3 things?
2. Fluorescein: Used to Assess what?
   a. You can also Use a BURTON LAMP instead of Cobalt Blue Filter in the Slit Lamp, but it DOES NOT WORK if the GP Material has what?

b. Wratten Filter also USED: Where is it PLACED (we used this in fitting on tuesday)?

Answer 13

1. Lens Lid Relationship, Centration, and Movement
2. Lens-Cornea Relationship
   a. Can’t use a BURTON LAMP if GP material has a UV FILTER!
   b. It’s put in FRONT of the OBJECTIVE LENS, NOT the Light Source!

Question 14

Presence vs. Absence of Fluorescein

1. Presence of Fluorescein
   a. Looks like what Color?
   b. Referred to as what 2 things?
2. Absence of Fluorescein
   a. Looks like what color?
   b. Referred to as what?

Answer 14

1. a. GREEN
   b. CLEARANCE of POOLING
2. a. BLACK
   b. BEARING or TOUCH

Question 15

Fluorescein Pattern

1. Describe the Fluorescein Pattern in What 3 Areas of the Lens?

Answer 15

1. Centrally/Apically, Midperipherally, and Peripherally

Question 16

When Describing the Fluorescein Pattern in the Central, Midperipheral, and Peripheral Locations, what will you say?

a. How will you describe it?

Answer 16

1. Either that there’s Pooling/Clearance OR that you see Bearing/Touch
   a. Say that it’s Minimal, Moderate, or Excessive

Question 17

Centrally

1. What is Acceptable for Staining?
2. What is Unacceptable?
3. When it’s Acceptable: What can you see?
4. What if you are Seeing EXCESSIVE POOLING?
5. Excessive Bearing: How will you see it?
   a. Causes what on the Cornea?

Answer 17

1. Minimal Bearing, or Minimal-moderate Clearance
2. Moderate-Heavy Bearing, and Excessive Clearance
3. Minimal Clearance; Thin NaFl; and you can still SEE THE PUPIL!
4. It will OBSCURE the PUPIL and you MAY see BUBBLES
5. Well-defined Area of Bearing (Distinct Borders)
   a. Mechanical Stress on the cornea

Question 18

Midperipheral

1. Acceptable?
2. Unacceptable?
3. Excessive Pooling: What will you see?
4. Excessive Bearing: What will you see?
   a. Will cause 1/2 things?

Answer 18

1. Min-Moderate Bearing; Minimal Pooling
2. Heavy Bearing; Moderate-Excessive Pooling
3. Thick NaFl Band extending from Periphery into Midperiphery
4. Well-Demarcated Ring of Bearing (Distinct Borders)
   a. Cause Binding and/or Corneal Compromise

Question 19

Peripherally

1. Acceptable
   a. What will you see?
2. Unacceptable
   a. Excessive?
3. When can you tell it’s insufficient?

Answer 19

1. Min-Mod Clearance
   a. Moderate band of NaFl at Edge
2. ANY BEARING, EXCESSIVE CLEARANCE
   a. Thick Band of NaFl at Edge; Edge Standoff; May see Bubbles
3. Thin Band of NaFl at Edge and there’s insufficient Tear Exchange (SUCTION)

Question 20

Is the Lens Steep, Flat, or Aligned to the Cornea?

1. Apical Lens-Cornea Relationship
   a. Alignment
   b. Clearance
   c. Touch

Answer 20

1. a. Back surface of lens matches the Corneal Curvature of the Apex (Aligned)
   b. Space b/w the lens and Corneal Apex (STEEP)
   c. Lens is touching the Corneal APEX (FLAT!)

Question 21

Static Assessment

1. Lens Centered on what?
2. Hold lids out of the way and determine relationship b/w what?
3. What does this tell us?

Answer 21

1. on Cornea
2. out of the way
3. gives us the TRUE APICAL RELATIONSHIP

Question 22

Dynamic Assessment

1. What is it?
2. What the lens dynamics as the pt does what?
3. Pattern looks different than when it’s what?

Answer 22

1. Natural Way the lens sits
2. blinks
3. when it’s centered

Question 23

1. Dynamic: Doing what?

2. Static: looking at what pattern?

Answer 23

1. Lid-lens relationship; Centration; Movement

2. Fluorescein Pattern

Question 24

What are the 4 Things you need to comment on when fitting a GP?

Answer 24

1. Lid-Lens Relationship
2. Centration
3. Movement
4. Fluorescein Pattern

Question 25

Toric Fluorescein Patterns

1. When a SPHERICAL BASE CURVE lens it FIT on a TORIC CORNEA, what is seen?
   a. WTR
   b. ATR

Answer 25

1. a characteristic pattern; More Corneal Toricity = More distinct Pattern
   a. Pattern will be in the 180 region
   b. Will be in 090 region

Question 26

Meridian of Least Resistance

1. GP will “rock” around what?
2. so WTR cornea?
3. ATR Cornea?

Answer 26

1. the Meridian of LEAST RESISTANCE
2. Up and Down
3. Side to Side