Lecture 8 - Tonometry 1

Question 1

When do you perform Tono?

Answer 1

After the SLEx

Note: If you do Gonio first, it will give you different result

Question 2

What type of focus and movement must be made by using the joystick for tono?

Answer 2

Fine focus and movement

Question 3

What is Tonometry?

Answer 3

The clinical technique that measures the IOP

Question 4

Where is the Aqueous humor produced by?

Answer 4

Epithelium of the Ciliary Body

Question 5

What is the flow of the Aqueous Humor?

Answer 5

Pupil into the Anterior Chamber

Question 6

What are the 2 routes for Aqueous Humor?

Answer 6

1. “Conventional Route”: passes thru the trabecular meshwork into Schlemm’s canal. Exiting via collector channels into venous system
2. “Unconventional Route”: passes thru the uvealscleral pathway. Passes thru the iris root uveal meshwork and the anterior face of cilary muscle à thru suprachoroidal space and on out thru sclera (Prostoglandins can be used)

Question 7

What is the outflow percentage of Aqueous Humor Outflow?

Answer 7

Trabecular outflow 70% or more

Uveoscleral outflow 30% or less

Question 8

What is the 3 IOP purposes?

Answer 8

1. Maintains integrity of globe
2. Maintains retina and choroid in place
3. Nourishes the lens, endo of cornea, vitreous and TM

Question 9

What is the normal range for IOP?

Answer 9

10 to 21

Note: Avg tends to be around 15 mmHg

Question 10

What is another scientific name when the outflow rate is normal?

Answer 10

Dynamic Equilbrium

Question 11

What are 2 abnormal changes of IOP?

Answer 11

1. Rare is overproduction in presence of normal outflow cause of increased IOP
2. Interference with aqueous outflow is the most significant factor in the etiology of increased IOP (MOST COMMON)

Question 12

What is the main focus of glaucoma therapy in regards to outflow?

Answer 12

Increase outflow and inhibition of production

Question 13

What drugs focus on outflow of aqueous humor and aqueous production?

Answer 13

Prostaglandin = outflow

Carbonic Anhydrase Inhibitor = production

Question 14

When you have completed multiple readings, what happens to the aqueous outflow and to IOP?

Answer 14

Increased aqueous outflow

Decrease IOP

Question 15

What is the diameter of the circular zone of applanation?

Answer 15

3.06 mm

Note: Area is 7.3542

Question 16

In regards to the GAT, what does 2 grams equal to in mmHg?

Answer 16

20 mmHg

Question 17

What is the first thing you must do prior to GAT procedures?

Answer 17

Pt. education

Question 18

Why is it important to remind your pt. that they must not rub their eyes ?

Answer 18

This is so why there is more of an effect on the eyes

Question 19

What parts do you puntcal occlude?

Answer 19

Nasolacrimal sac and medial palpebral ligament

Question 20

What are the three chemical components of fluress?

Answer 20

Fluorescein, Benoxinate and Chlorobutanol

Question 21

What is the wetting agent and stabilizer?

Answer 21

15% Povidone

Question 22

What do you ask your pts. prior to distilling dyes or anesthetics?

Answer 22

Are you allergic to any dyes or anesthetics

Question 23

When inserting a tono probe, what markers must be aligned with one another?

Answer 23

Holder = white line

Tono probe = zero axis

Question 24

When do you align on the red line of the holder?

Answer 24

3D or more of CORNEAL ASTIGMATISM

Question 25

What is the separation degree between the red and white line on the holder?

Answer 25

43 degrees

Question 26

Why do we not start the drum set too high?

Answer 26

Since the avg is close to 15 mmHg.

Question 27

How many degrees and in what direction is the viewing system arm away from the GAT reference point?

Answer 27

5 to 10 degrees away and temporally Note: GAT must be perpendicular patient's corneal plane

Question 28

What is the magnification you use when scanning the cornea after probing?

Answer 28

10x

Question 29

While looking externally and pushing the slit lamp close to the pts. eye, when is it your indication to start looking through the eye piece of the slit lamp?

Answer 29

Limbal glow

Question 30

If the mires are too thick, how will that impact the IOP?

Answer 30

Artifically higher IOP Note: The opposite is true for thin mires

Question 31

What type of motion occurs when there is venous pulsation?

Answer 31

Lateral motion of the mires

Question 32

True or False. Mires that come and go means they are pulsating mires?

Answer 32

False. This means that there is not proper applanation

Question 33

What is the most common type of virus that can occur when you do NOT clean the tono probe?

Answer 33

Adenovirus Keratoconjunctivitis

Question 34

What type of wash removes all types of viruses available, even HepB virus of the DNA?

Answer 34

Water Wash

Question 35

What does the AOA recommend when cleaning the tono probe?

Answer 35

70% isopropyl alcohol swab