Mydriatics

Question 1

What are mydriatic drugs used for ?

Answer 1

Induce Pupil dilation

Question 2

What is function of pupil?

Answer 2

regulate amount of light entering the eye and reaching retina

Question 3

List purposes of using mydriatic drugs

Answer 3

• obtain better view of fundus
• therapeutic use in anterior uveitis - breaking posterior synechia
• get iris out of way in surgical procedure

Question 4

List indications for using mydriatic drugs

Answer 4

• ocular dysfunction - reducation in VA , doubt about the cause
• stereoscopic view required
• Pts at risk of ocluar disease , RD in high myopes

Question 5

What sx may a pt present with that would indicate you would need to do a dilated fundus exam

Answer 5

flashing light and increased floaters

Question 6

Advantages of optoms using mydriatic drugs include

Answer 6

• Large FOV
• 3d view of retina
• peripheral exam of retina
• peripheral exam of lens and vitreous

Question 7

explain the pharmacological methods of mydriasis

Answer 7

• blockage of parasymtphamic branch of ANS
• stimulate sympathetic branch of ans
• combination of antimuscarinic and sympathomimetic in eye

Question 8

List pre dilation checks that should be carried out in a pt

Answer 8

Measure ...
IOP
AC angles 
VA 
pupil responses 
previous adverse/allergy to drug 
4d test
other contraindications - IRIS FIXATED IOL
preganancy ?
discuss tasks that need to be avoided

Question 9

List post dilation checks …

Answer 9

IOP 
AC angles 
VA 
pupil response 
Given written material to pt

Question 10

contraindications of using mydriatic drugs

Answer 10

• previous allergic reaction
• narrow AC angles
• iris fixated IOL

Question 11

What should be discussed with your pt when using a mydriatic drug?

Answer 11

why u are putting drops in 
effect of drug 
how long effect will last 
tasks that should be avoided 
possible side effect 
what do to inacse of ADR

Question 12

what is the key risk you should be mindful of when using a mydriatic drug on a pt

Answer 12

acute angle closure glaucoma

Question 13

sx of acute angle closure glaucoma …

Answer 13

Headache
haloes around lights
nausea
ocular pain

Question 14

At pt at risk of angle closure will have a van hericks ratio of

Answer 14

1.0.25 or less

Grade 2

Question 15

How would you know if a patient is at risk of angle closure galucoma

Answer 15

check IOP post dilation and increase in 5mmHg unilateral - treat with suspicion

Question 16

What mydriatic drugs are available to optoms ?

Answer 16

Tropicamide

Phenylephrine hydrochloride

Question 17

What concentration is tropicamide avail in

Answer 17

0.5 and 1%

Question 18

What is the legal classification of tropicamide

Answer 18

POM

Question 19

What concentration in Phenylephrine hydrochloride in

Answer 19

2.5 and 10%

Question 20

Legal classification of phenylephrine hydrochloride is

Answer 20

P

Question 21

How does tropicamide work in the eye

Answer 21

antimuscarinic agent
competitive antagonist for muscarinic receptors
prevents acetylcholine binding - prevents contraction of sphincter muscle - unopposed action of dilator muscle = causes dilation

Question 22

Tropicamide drug type :

Answer 22

Mydriatic and cycloplegic

Question 23

Tropicamide Onset

Answer 23

15-20mins

Question 24

Recovery of Tropicamide

Answer 24

6-8 hours

Question 25

After how long does the dilation begin to wear of off tropicamide

Answer 25

after 2H

Question 26

In which situation would u use the conc available of tropicamide

Answer 26

0.5% - commonly used in all pts - good mydriases and minimal cycloplegia 1% - pts with high melanin pigmentation in iris

Question 27

Reversal of tropicamide can be done with

Answer 27

2% Pilocarpine - stimulates PNS not avail to optoms risk of psuedomyopia

Question 28

Phenylephrine hydrochloride works by

Answer 28

stimulating Sympathetic branch - sympathomimetic drug acts directly on a1 adrenoreceptors , stimulates the radial muscles of iris = causes dilation

Question 29

what effects does PH have on the eye

Answer 29

- blanching of conj blood vessels - whiter due to narrowing of vessels - increased palpebral aperture due to stimulation of mullers muscle - pupil dilation - asymmetric ?

Question 30

State pupil reflex of when using Tropicamide and PH on eye

Answer 30

T- wont get reponse when light shone in eye , will stay dilated PH - pupil will close up as sphincter muscle is unaffected

Question 31

onset of PH

Answer 31

approx 1 Hour

Question 32

Recovery of PH

Answer 32

3-4 Hours

Question 33

reversal of PH

Answer 33

Thymoxine not avail - blocks SNS antagonist

Question 34

List contraindication for USE OF PH

Answer 34

8

Question 35

Indication for using phenylephrine hydrochloride

Answer 35

fundus photogrpahy use in isolation when moderate dilation req sector dilation

Question 36

state other uncommon mydriatics

Answer 36

cyclopentolate hydrochloride ' cocaine hydroxy amphetamine

Question 37

cocaine was historically used to investigate

Answer 37

horners syndrome

Question 38

onset of recovery of cocaine and hydroxyamphetamine

Answer 38

20-40 mins , last 6 hours 45 mins , lasts 3-6 hours