Knowledge

Question 1

Spherical RGP lenses on against-the rule corneas tend to decenter…

Answer 1

laterally

Question 2

by increasing the overall lens
diameter, increasing the size of the
optic zone or steepening the base
curve of the lens does this to an RGP lens

Answer 2

Steepens the lens to cornea relationship

Question 3

A lens that has become adherent
to the cornea may leave an
impression that can be viewed
after the lens has been removed.

Answer 3

leaves slightly darker spot

Question 4

Neovascularization of the cornea in a soft contact lens could indicate …

Answer 4

A lack of oxygen transmission through the lens, a tightly fitting soft lens or a situation in which the patient overwears

Question 5

edge stand off or lift can occur

Answer 5

when soft contact is fit too flat to the cornea

Question 6

Soft lens should be …mm larger than the patient’s HVID

Answer 6

2
Hvid= 11-12
diameter should be = 14ish

Question 7

The difference between Neovascularization and Pannus is…

Answer 7

Neovascularization: develops in an already compromised cornea
Pannus: caused by ill fit, typically at superior limbus.

Question 8

Is chalazion or stye (hordeolum) usually above the eye and a raised lump

Answer 8

Chalazion

Question 9

Is chalazion or stye (hordeolum) a point/ pimple on lash line usually below eye

Answer 9

Stye

Question 10

When Superficial Punctate Keratitis has an isolated pattern this is because…

Answer 10

there is a poor contact lens fit or infection

Question 11

When Superficial Punctate Keratitis has a diffuse pattern this is because …

Answer 11

There may be solution toxicity or an interaction between certain lens/solution combinations or dry eye syndrome.

Question 12

Steepest on 90 flattest on 180

Answer 12

With the rule astigmatism

Question 13

a rigid lens will ride superior-inferior with the interaction of the eyelids during a blink

Answer 13

With the rule astigmatism

Question 14

will tend to ride medial-lateral

Answer 14

Against the rule

Question 15

inconsistent with the blinking action of the eyelids

Answer 15

Against the rule

Question 16

Keratometer measures … after surgery

Answer 16

low

Question 17

Average keratometer measurement is …

Answer 17

47-48

Question 18

Above-average keratometer measurement means keratoconus

Answer 18

(52) (51)

Question 19

Contact inverted and not inverted looks like

Answer 19

Inverted flares out at top and bottom more angular

correct way has rounded edges and bottom

Question 20

Normal Tbut

Answer 20

greater than 10 seconds

Question 21

Schrimer test 1

Answer 21

After 5 mins
Normal-greater than 15mm
Mild-10-14mm
Moderate- 5-9mm
Severe- less than 5mm

No drops
small strips of filter paper inside the lower eyelid

Question 22

Schirmer test #2

Answer 22

Less than 6mm of wetting after 5 mins is abnormal

Anaesthetic drops used

A cotton swab inserted into the nose

Question 23

Marginal Tbut

Answer 23

greater than 5 and less than 10

Question 24

Low Tbut

Answer 24

Less than 5 seconds = dry eye symptoms

Question 25

ptosis

Answer 25

Upper eyelid droops below normal position

Question 26

trichiasis

Answer 26

eyelashes grow inwards toward the eye

Question 27

Ectropion

Answer 27

Droop of the lower lid

Question 28

lagophthalmos

Answer 28

incomplete closure of the eyelids

Question 29

Entropion

Answer 29

turning inward of the eyelid making eyelashes touch globe

Question 30

The deeper the layer of tears the ... the fluorescein green will be.

Answer 30

brighter

Question 31

The less tears in the tear layer the ... the fluorescein green will be

Answer 31

darker

Question 32

Before insertion scleral lenses are washed down with ... and filled with ...

Answer 32

saline solution

Question 33

Involuntary, jerking movements of the eyes

Answer 33

nystagmus

Question 34

Central Abrasion

Answer 34

This stain is caused by a large break or erosion in the corneal epithelium. Can be caused by a flat lens or other mechanical irritation or extended corneal edema. Pic:book

Question 35

Peripheral abrasions

Answer 35

Caused by mechanical irritation or chipped/damaged lens. Could be poor insertion or removal techniques. Pic:book

Question 36

3-9 o'clock staining

Answer 36

Caused include poor blinking/incomplete blink, flat edge curves, and poor edge design(thick edge) Dry tear film breakdown

Question 37

Arcuate

Answer 37

Due to poor blends or peripheral curves

Question 38

Dimple veil staining

Answer 38

Caused by air bubbles that have been trapped centrally under the lens due to a poor fit that is too steep, or in the limbal area by a lens that is too flat. It is not a breakage but rather a denting of the surface of the epithelium

Question 39

Stippling/punctate stains

Answer 39

Caused from dryness, lack of oxygen to cornea, associated with PMMA lenses, but can also be found in dirty gp lenses or low Dk gp lenses. Chemical toxicity can also contribute

Question 40

Solution induced corneal staining

Answer 40

Small dots around entire surface or in periphery caused by solution toxicity/insensitivity