Mydriasis and Cyclopegias

Question 1

What are the main two enzymes responsible for sympathetic metabolism?

Answer 1

COMT and MAO

Question 2

What is substrate for sympathetic neurotransmitters?

Answer 2

Tyrosine

Question 3

What are the steps in Sympathetic nerve activity?

Answer 3

1. Tyrosine converted to Dopa (also catecholamoine)
2. Dopa- to dopamine (lipid membrane vessels)
3. Dopamine converted NE
4. NE increases causes an action potential causes calcium to come into nerve terminal
5. High Ca. vesciles fuse open up to exterior and releases
6. COMT can metabolize NE
7. Stimulation of alpha 2 stops degranulation
   NE remains will be reabsorbed by nerve. MAO will determine fate

Question 4

What blocks reuptake of NE?

Answer 4

Cocaine (works indirectly and amplifies neuros)

Question 5

What receptor inhibits sympathetic system ?

Answer 5

alpha 2

Question 6

What is a precursor for tyrosine and melanin?

Answer 6

phenylalanine (too much can change simp pathway)

Question 7

What causes lid retraction

Answer 7

Muellar’s (sympathetic)

Question 8

What drug can be responsible for ptosis?

Answer 8

drug that stimulates Muellar’s (eye that seems to have ptosis doesn’t really have a ptosis its due to retracted eye lid)

Question 9

Dilating in specific area?

Answer 9

sectoral dilation (keyhole pinhole)

Question 10

Large angles found in?

Answer 10

myopes and aphakes

Question 11

Reduced Sensitivity?

Answer 11

Age Related Miosis (older= smaller pupils
Unstable Diabetics
Post op pupils (drugs affect ANS)
Posterior Synechiae (iris stuck to lens)
Dark Irides
Pseudoexfoliation syndrome (iris looses muscle tone)

Question 12

Increased Sensitivity

Answer 12

Down Syndrome (respond aggressively)

Question 13

Poor Dilation Candidates?

Answer 13

Homocyternia and Marfan Syndrome
Pregnancy (use tropicamide)
Pigmentive glaucoma

Question 14

Contraindications for dilating patients?

Answer 14

Lens/ Angles

Angle Closure can occur 4-8 hours after dilating drops

Question 15

Sympothoaminmetic Amines?

Answer 15

Phenylepinephrine

Hydroxyamphetamine

Question 16

Drugs used for red eye relief/ Decongestants that stimulate a and b receptors

Answer 16

Oxymetazoline
Naphazoline (Clear eyes)
Tetrahydrozoline (Visine)
Can cause Ptosis and Anisicoria

Question 17

Phenylephrine

Answer 17

alpha 1: mydirasis

indiectinly cause NE to be released into cleft

Question 18

How long does it take phenyleph. to produce mydriasis?

Answer 18

45- 60 min. This is the reason it is never used alone.

Question 19

Common Indications of phenylephrine?

Answer 19

mydirasis 45-60 
conuncitivl blnching
mild accommodation suppression 2D
Lid retraction 
IOP reduction

Question 20

synergist of phenyllynine?

Answer 20

MAOis
TCADs
Atropine

Question 21

antagonists of phenyeph.

Answer 21

methyldopa

Beta

Question 22

Effects of phenyl?

Answer 22

rebound miosis and congestion
bur
photophobia
anterior chamber pigment liberation 
hypertension: bradychar

Question 23

Contraindications of phenyl

Answer 23

aneurisym, DM 1, CVD, MI, ateriosclerois, idio orthro hypotension

Question 24

What doesn’t suppress accommodation ?

Answer 24

Hydroxyamphetamine

Question 25

Key nearotransmitter parasympathetic system?

Answer 25

Acetylcholine

Question 26

Key enzymes used in parasympathetic pathway?

Answer 26

Ache- found in nerve terminals

Bche- found in plasma

Question 27

What inhibits calcium degranulation in parasympathetic pathway?

Answer 27

Botox (muscle paralysis)

Question 28

Atropine

Answer 28

nonselective for M

can bind to N

Question 29

What anticholinergic does the same job as atropine but at a lower %

Answer 29

homatropine

Question 30

what is the safest dilating agent/

Answer 30

tropicamide. M4 selective

Question 31

Drops completelly knock out accommodation?

Answer 31

cyclopentolate

cyclomydril

Question 32

What else can be used as cylcopeg?

Answer 32

Atropine

Question 33

dilate paitients with uveitis/amblyopia?

Answer 33

Atropine

Question 34

Adverse effects of anticholinergic

Answer 34

increase in IOP
angle closure risk
allergy
ABCSs

Question 35

Wht anticholinergic drug cases delay in darkly pigmented eyes/

Answer 35

cyclopentalate (also less drying)

1 drop 15 mi 1 drop 30 min

Question 36

Which drop causes fastest cycolpegi?

Answer 36

Tropicamide 20-35 min up to 6 hours

atropine slowest 60-80 min last up to 12 days

Question 37

Which is a dose dependent cyclopeia?

Answer 37

Tropicamide