1 - indications for CL use

Question 1

What are the types of Cls

Answer 1

1. Rigid
2. Soft
3. Hybrids
4. Silicone rubber

Question 2

What are the materials of RGP

Answer 2

• PMMA
• Gas permeable materials

Question 3

What is the size of RGP lenses

Answer 3

Smaller than corneal diameter (9.5mm)

Question 4

What are the materials of SCLs

Answer 4

1) hydrogel
- hydrophillic (different water contents)

2) silicone hydrogels
- high oxygen (EW)
-mixture of silicone rubber and hydrophllic material

Question 5

What is the size of SCLs

Answer 5

Larger than corneal diamter (14mm)

Question 5

What is the size of SCLs

Answer 5

Larger than corneal diamter (14mm)

Question 6

What are refractive indications of CL wear

Answer 6

• myopia (control, improved acuity, greater FOV)
• hyperopia (possibility of reduced acuity)
  -astigmatism (if DC < DS, possibility of reduced acuity)
• anisometropia
• BV problems

Question 7

What are pathological indications of CL wear

Answer 7

• cranio -facial abnormalities
• allergies (specs - metal/rubber)
• irregular cornea
• keratoconus
• bandage
• protection
• cosmetic

Question 8

what are some contra-indications

Answer 8

• occupational: - dust/chemical vapours/PC use/ poor ventilation
• allergies
• poor hygiene (conjunctivitis, bleph, smoker, herpes zoster)
• ill health (implications on tear film quality - DM, h-thyroidism/arthirits/menopause)
• age? ability to handle CLs (infant, student, presbyope)

Question 9

RGP - why choose?

Answer 9

• Vision (amazing)
• corneal irregularity
• handling
• dry eyes (refit)
• compliance (less chance of infection)
• SCL failure

Question 10

SCL - why choose?

Answer 10

• comfort
• infrequent wear
• environment
• RGP failure incl. fitting problems

Question 11

When is slit lamp used in CL practice

Answer 11

• CL fitting (baseline measurements)
• Aftercare (lens fit, surface condition, ocular integrity)

Question 12

When would you use low mag (6-10x)

Answer 12

General eye
- lids/lashes
- cornea
- conjunctiva
- sclera

Question 13

When would you use medium mag 16x

Answer 13

to view structures
- blepharitis
- MGD
- concretions

Question 14

When would you use high mag (25-40)

Answer 14

details (of cornea)
- epithelial changes
- stromal striae + folds
- endothelial folds/blebs ( caused by corneal oedema - lack of oxygen)

Question 15

When do you see striae in the stroma

Answer 15

• more corneal swelling

Question 16

what does it mean when you see folds

Answer 16

-more than 10% corneal swelling - dangerous

Question 17

why use cobalt blue feature

Answer 17

excites fluoroscein dye

Question 18

green (red-free filter)

Answer 18

enhance contrast of blood vessels

Question 19

neutral density filter

Answer 19

reduces beam brightness
- increases px comfort

Question 20

wratten filter

Answer 20

• enhances NaFI staining when used with blue light (and MAX illuminiation)

Question 21

what does fluoroscien do

Answer 21

• highlights epithelial defects as stains areas of missing cells
• dye may disappear after 2-4 mins
• use cobalt blue filter at high illumination

Question 22

pics of staining

Answer 22

Question 23

When is specular reflection used

Answer 23

to assess tear film and endothelium (high mag)

Question 24

what is retro illumination

Answer 24

back light from iris or fundus

Question 25

what can be viewed with from retro illumination

Answer 25

- vacuoles - microcysts

Question 26

what is the genersl SL routine

Answer 26

start with white light - general look at ocular adnexea - diffuse, low mag, whole eye - sclerotic scatter, low mag increase mag, parallelpipied - lashes, lid margins - tear prism height - conjunctiva + cornea change to optic section on high mag to assess depth of anything unusual investigate limbus separately

Question 27

after general view on slit lamp?

Answer 27

use blue light and NaFi - staining - conjunctiva - cornea - location - TBUT - LID MARGIN`

Question 28

AFTER BLUE LIGHT

Answer 28

- lower and upper lid eversion - meiboiam glands

Question 29

SL when lens is in the eye?

Answer 29

Lens fit + conditions - diffuse, direct/ indirect for centration and movement - direcr for fit + surface condition

Question 30

what are the 2 grading scales

Answer 30

- CCLRU - Efron grading scale

Question 31

CCLRU grading scale features, what are adv and disadv

Answer 31

real pics - advantage - grade 1 -4 disadvantages 1) different eyes 2) different illuminations

Question 32

efron grading scale features (adv and disadv)

Answer 32

pictoral - disadvantages - grade 0-4 advantage: - precise severity shown - image cosnsistency

Question 33

when grading we grade to the nearest?

Answer 33

0.5

Question 34

grade 2 or less is considered .....

Answer 34

normal limits

Question 35

what grade change is considered clinically significant

Answer 35

more than 1 grade

Question 36

importance of record keeping

Answer 36

- monitering progression - record across time - px communication

Question 37

principles of grading scales

Answer 37

Question 38

when to check corneal staining

Answer 38

before and after fitting

Question 39

types of corneal staining (pic)

Answer 39