Anesthetics And Methods Of Drop Delivery

Question 1

What is the reason we use topical ocular anesthetic

Answer 1

Used to prevent eye pain during several procedures

Question 2

Use topical ocular aesthetics to prevent eye pain during:

Answer 2

• diagnostics testing and procedures
• applanation tonometry
• gonioscopy
• ophthalmic examinations
• removal of foreign bodies or sutures
• surgery

Question 3

What are some commonly used anesthetics used?

Answer 3

• cocaine
• tetracaine
• benoxinate
• proparacaine

Question 4

Mechanism of action of topical anesthetics

Answer 4

• blocks nerve conduction to superficial cornea and conjunctiva by disabling the ability of the nerve cells to generate an action potential
• suppresses corneal and conjunctival sensitivity

Question 5

Efficacy of topical anesthetic

Answer 5

-determined by their ability to suppress corneal sensitivity

Question 6

Combining two ore more topical anesthetics

Answer 6

Does not produce an additive effect, but does increase the risk of slide effects

Question 7

Side effects of topical ocular anesthetics

Answer 7

Severe local reaction are rare, systemic reaction are even more uncommon

Question 8

Ocular toxicity of topical of anesthetic

Answer 8

• mild stinging and burning
• desquamation of corneal epithelium
• retards epithelial healing

Question 9

What the most common side effect

Answer 9

Mild stinging and burning

Question 10

What can increase the risk of adverse effects of topical anesthetic

Answer 10

Self medication

Question 11

System toxicity of ocular anesthetic

Answer 11

Overdose from topical administration theoretically possible

Question 12

Local hypersensitivity reactions to anesthetics

Answer 12

• Allergy can develop due to repeat exposure (glaucoma patients)
• mild transient blepharoconjunctivitis occurring 5-10 minutes following instillation
• little cross reactivity among topical anesthetics

Question 13

Cross reactivtiy among topical anesthetics

Answer 13

Little cross reactivity

Usually only sensitive to one drug

Question 14

Systemic hypersensitivity reactions to local anesthetics

Answer 14

No lifer threatening reactions reported

Question 15

Self administration of topical anesthetic

Answer 15

• risk of adverse effects due to corneal toxicity

- vision loss secondary to permanent scarring

Question 16

Hypersensitivity to topical anesthetics

Answer 16

Substitute different agent; little cross-sensitivity

Question 17

Topical anesthetic and cultures

Answer 17

• they are toxic to micro organisms plus proparacaine least toxic
• will making getting a culture of bacterial infection difficult

Question 18

Dry eye testing and topical anesthetics

Answer 18

-epithelial toxicity can confuse clinical picture

Question 19

Pachymetry and topical anesthetics

Answer 19

Transient corneal swelling following anesthetic use

Question 20

Perforating injuries and topical anesthetics

Answer 20

Endothelial toxicity

Question 21

what is the concentration of proparacaine?

Answer 21

0.5% soln

Question 22

How should proparacaine be stored?

Answer 22

In a tightly capped, opaque, and (ideally) refrigerated container to retard degradation

Question 23

What should you do if proparacaine shows more than a faint yellow color?

Answer 23

It should not be used

Question 24

Systemic toxicity of proparacaine

Answer 24

Extremely low

Question 25

Penetration of proparacaine

Answer 25

Poor penetration of the conjunctiva and cornea | -quick to work, quick to wear off

Question 26

Which is the least bacteriocidal of the topical anesthetics?

Answer 26

Proparacaine

Question 27

Order of topical anesthetics in corneal toxicity from high to low

Answer 27

Tetracaine Proparacaine Benoxinate

Question 28

Which topical anesthetic is least uncomfortable?

Answer 28

Proparacaine | Use prior to routine office procedures

Question 29

Duration of action of proparacaine

Answer 29

Onset 10-20s | Duration 10-20 min

Question 30

Contraindications and precautions of proparacaine

Answer 30

- corneal thickness instability lasting 5 minutes | - pregnancy category C (not completely safe to use if pregnant

Question 31

Side affects of proparacaine

Answer 31

Allergy (rare)

Question 32

Goal of eye drop instillation

Answer 32

To deliver a full dose of the drug to the eye while minimizing systemic exposure and maximizing patient safety and comfort

Question 33

What is the preferred method for routine eye drop instillation?

Answer 33

Inferior fornix delivery

Question 34

Why is inferior fornix delivery the preferred method for routine eye drop instillation?

Answer 34

- maximizes ocular contact time of drug - minimizes drug loss - increases ocular absorption - and decreases systemic absorption

Question 35

Steps for inferior fornix delivery

Answer 35

- tilt head back - tell pt to look up - pull lower lid away from globe - check expiration date, shake and remove cap - instill gt in lower eyelid (hold about 1" above the pocket) - AVOID CONTAMINATION OF TIP - place drop on conjunctiva, not cornea - close eyes gently for 3 min - apply pressure to puncta

Question 36

Purpose of punctual occlusion after eye drops

Answer 36

- minimize drainage of medication into nasolacrimal apparatus, thereby maximizing ocular contact - decrease systemic absorption of drug through nasal mucosa, minimizing risk of systemic adverse effects

Question 37

Method of punctual occlusion after eye drops

Answer 37

Following eye drop instillation, instruct patient to close his eyes and apply gentle pressure to the medial canthal region for about 3 minutes

Question 38

Recording eye drop instillation

Answer 38

-record name of the pharmaceutical agents used, including its cxn, how many drops used in each eye, and time of day 1 gt of 0.5% proparacaine OD and OS @ 11.35 AM

Question 39

Alternatives to the instillation of eye drops

Answer 39

- medial canthus delivery - spray bottle - pledgets

Question 40

Medial canthus delivery of eye drops

Answer 40

A lower anxiety technique for persons unable to cooperate with inferior fornix delivery

Question 41

Technique for medial canthus delivery

Answer 41

- Head inclined back - eyes closed - eye drops placed on top of medial canthus - patient instructed to blink repetitively

Question 42

Spray bottle technique

Answer 42

- mist applied to closed lids with spray bottle and the patient be instructed to blink - excess solution should be wiped off - a second spray might be necessary, especially if the eyes were closed too tightly

Question 43

Advantages of spray bottle

Answer 43

- efficacy reported to be equivalent as ophthalmic drops and more tolerable - patients were more compliant and experienced less burning when the spray was used than when the ophthalmic drops were used

Question 44

Disadvantages to spray bottle

Answer 44

- inability to deliver precise dosage - lack of an established dose-response relationship for this type of administration - potential for drug contamination - most ophthalmic medications are not currently formulated for this type of application

Question 45

Pledgets

Answer 45

- cotton swab saturated with drug solution then placed in the eye - permits very long or very short contact time - useful of inferior sector dilation, breaking synechia