Final Everything

Question 1

Scleral fitting

-lens insertion

Answer 1

Non-presverved sol’n

Over-fill the bowl

Question 2

Scleral fitting

-3 zones

Answer 2

Central
Limbal
Edge

Question 3

Scleral fitting

-brief how to fit

Answer 3

HVID 1st

Methods: vault reduction or vault increase

Center, clear entire K, no bearing on limbus, smooth alignment with sclera

Question 4

Scleral fitting parameters and sag

-base curve radius (BC)

Answer 4

Decr in mm = incr sag

Incr in D = incr sag

Question 5

Scleral fitting parameters and sag

-total diameter (TD)

Answer 5

Incr = incr
Decr = decr

Question 6

Scleral fitting parameters and sag

-peripheral curve radii or angle (PC)

Answer 6

Decr in mm = incr sag

Incr in D = incr sag

Question 7

Scleral fitting parameters and sag

-limbal curve radii (LC)

Answer 7

Decr in mm = incr

Incr in mm = decr

Question 8

Scleral fitting

-removal

Answer 8

Small DMV

Lower 1/3rd

Question 9

Scleral fitting

-evaluation

Answer 9

Out to in

1) overall
- white light = movement, centration, push up/in/rotate
- blue light = zone sizes, tear layer thickness

2) scleral alignment
- white light = vessels for obstruction

3) limbal clearance
- compare LC to CT (“thou shalt not touch the limbus”)

4) central clearance
- white light = compare CT to K

5) over-refraction
- SAM FAP

Question 10

Scleral fitting

• fit is based on
• key

Answer 10

Scleral shape

Sag

• controls vaulting, desired tear layer thickness (100-600 microns)
• should match eye + desired tear layer reservoir

Question 11

OrthoK fitting

-myopia control

Answer 11

Atropine > soft bifocal > OK > spectacles > GP

Question 12

OrthoK fitting

-how it works/physiology

Answer 12

Epithelial layer changes

• normal 50 microns
• incr in periphery, decr in center
• redistribution “to certain extent”

Question 13

OrthoK fitting

• materials
• fit as __ as possible
• avg size

Answer 13

High Dk, PMMA

Flat

10.6mm, 90-95% HVID

Question 14

OrthoK fitting

-process

Answer 14

Start with best possible lens fit (mid-periph back surf aligned to K (AC))

Treatment zone (center, 6.0-6.5mm) is flattened

Question 15

OrthoK fitting

• BC formula
• most important thing

Answer 15

BC = (flat K) + (MRS) - (RR)

Centration = alignment curve (AC) is responsible

Question 16

CRT (Spors)

• RZD is available in what increments
• LZ (landing zone) is available in what increments

Answer 16

25 microns

1 degree (15 microns)

Question 17

CRT (Spors)

-if riding high/flat/loose

Answer 17

Need to incr RZD by 25 microns

Question 18

CRT (Spors)

-if thin edge clearance

Answer 18

Need to decr LZA by 1 degree

Question 19

CRT (Spors)

-if little/no central touch

Answer 19

Need to decr RZD by 25 microns

Question 20

CRT (Spors)

-what do the markings 915533 mean

Answer 20

BCR 9.1
RZD 550
LZA 33

Question 21

CRT (Spors)

-what the 3 types of topography map mean

Answer 21

Smile = flat

Island = tight

Bull’s eye = ideal

Question 22

CRT (Spors)

-if MRx is -1.00

Answer 22

Need to use larger RZD

-e.g. go from 8.6 to 8.8 (flatter to incr myopic correction)

Question 23

CRT (Spors)

-primary reason to change LZA from 33 to 34

Answer 23

Decr edge clearance

Question 24

CRT (Spors)

-what is a typical BOZD/OAD combo

Answer 24

6.0/10.5 (or 10.6)

Question 25

Nystagmus | -most common cause of opscillopsia

Answer 25

Arnold-Chiari - downbeat (fast phase down), greater in downgaze (reading) - pathognomonic lesions = congenital malformation hindbrain, downward elongation BS/cerebellum into cervical spinal cord area

Question 26

Nystagmus | -other causes

Answer 26

``` Foramen magnum tumor MS Spinocerebellar degen BS infarction Posterior fossa malformation ```

Question 27

Nystagmus | -reduction methods (2 main)

Answer 27

SRX with prism | SRX CLS telescope

Question 28

Nystagmus | -how CLS telescope system works

Answer 28

System - high plus specs = images closer to center of rotation - high minus CLS = restores focus to retina Decr amp and frequency - magnification - dampen convergence - decr rotational mag - tactile feedback from the lids - weight (?)

Question 29

Nystagmus | -limits of telescope system

Answer 29

Optical aberrations VF Requries stationary head (no tremors)

Question 30

Keratoconus | -ideal fit

Answer 30

Intra-peripheral 3-point touch - weight of CLS distributed across K - slight apical feather touch, paracentral celarance, mid-periph bearing, periph edge clearance - start with flat K BCR

Question 31

Blanchards | -OneFit design with excessive central clearance

Answer 31

To decr clearance = incr BC | 0.1mm change in BC = 50 micron change in clearance

Question 32

Piggybacks - when to use - lens types

Answer 32

``` Last resort (under-utilized) RGP intolerance (poor fit, sensitivity) ``` High Dk SiHy = comfort/fit (reduced edge sensation) -bandage CLS High Dk RGP = optics/regular spherical refractive surface High Dk = >100

Question 33

Piggybacks - GPLI - if pt has low K apex resulting in GP lens positioning low on SCL - contribution of lenses

Answer 33

Very lower power SiHy under the GP Use moderate plus SCL (+6.00) -thicker center lens thickness will help it center Moderate plus SCL has little-no effect because only 20% of it’s power contributes -e.g. +6.00 lens = +1.20 power

Question 34

Color vision | -CLS

Answer 34

Red for RG deficiency

Question 35

Special eyes arc length calculator | -requires what numbers

Answer 35

HVID Rx K’s

Question 36

CRT | -sag depth too shallow

Answer 36

Incr RZD = incr sag depth

Question 37

CRT | -sag depth too high

Answer 37

Decr RZD = decr sag depth

Question 38

CRT | -excessive edge clearance

Answer 38

Incr LZA = decr edge clearance

Question 39

CRT | -insufficient edge clearance

Answer 39

Decr LZA = incr edge clearance

Question 40

CRT - first to improve the fit - fine-tuning the fit

Answer 40

Change RZD Change LZA