Eye Disorder-glucoma

Question 1

Aqueous humour

Answer 1

Secreted by cells of the epithelium then into POSTERIOR CHAMBER (behind iris)

Then drains from ANTERIOR chamber to blood stream

Question 2

Intraocular pressure IOP

Answer 2

Determined by the vol of aqueous humour in ANTERIOR chamber of eye

Question 3

Glaucoma (raised IOP)

Answer 3

^IOP caused by blockage of circulation / drainage of AH

Result: damage /impaired blood sup to optic nerve -> which is slowly destroyed (irreversible)

Question 4

Types of glaucoma

Answer 4

Chronic (primary) open angle glaucoma

Acute angle closure glaucoma (need surgery)

Congenital glaucoma

Secondary glaucoma

Question 5

Treat primary/open angle glucoma

Answer 5

Prostaglandin analogue (1st line)

Beta-blocking analogue (2nd line)

Alpha 2 agonist (3rd line)

Carbonic anhydrase inhibitor

Question 6

Prostaglandins drugs

*ends with oprost

Answer 6

Latanoprost

Bimatoprost

Question 7

Prostaglandin MOA

*glucoma asymptotic- adherence / compliance to drug is major problem

Answer 7

Reduce IOP by increasing uveoscleral outflow

Outflow ⬆️~ pressure ⬇️

Possibly due to
• activation of molecular transduction cascade
• ^ in biosynthesis of certain metallo-proteinases
• reduction of extracellular matrix within uveoscleral pathway

Question 8

Prostaglandin AE

Applies to >1% pts

Answer 8

Irreversible increase in iris pigmentation

Darkening , lengthening , thickening of eyelashes

Eye irritation, blurred vision

Question 9

Beta receptors

Answer 9

B1 - heart
B2 - smooth muscle of bronchioles, aterioles, visceral organs
B3 - adipose tissue

Question 10

Adrenergic receptors

Answer 10

Alpha 1,2

Beta 1,2,3

Question 11

Cholinergic receptors

Answer 11

Nicotinic

Muscarinic

Question 12

B blocker (b receptor antagonist) 
MOA

Answer 12

Block B2 : reduce aqueous humour formation

⬇️production =⬇️ pressure

May also act on b2 on ciliary arteries and induce vasoC - further ⬇️ ptoduction

Question 13

B blocker AE

Answer 13

Systemic related ..

But and prevent by use appropriately
• close eye and pressure on tear duct for 3min after instillation
• systemic absorption reduce by up to 70%
• drug stay in eye rather than system

Question 14

B blocker drugs

*end with : olol

Answer 14

Timolol

Betaxolol

Question 15

Timolo

Answer 15

Non selective blocker
B1-heart B2-bronchioles

Not used in pts with cardio /airway disease

Question 16

Betaxolol

Answer 16

Selective B1 (cardio) yet still works in eye

Dose related - efficiency
Use with caution in pts with airway disease
But contraindicate in cadio

Question 17

Alpha 2 adrenergic agonist MOA

Answer 17

⬆️uveoscleral outflow = ⬇️ IOP

⬇️production = ⬇️IOP

Question 18

A2 agonist AE

Answer 18

Palpitation : irregular and rapid heart beat

Hypertension

Tremors

Question 19

A2 agonist drugs

* end with onidine

Answer 19

Apraclonidine

Brimonidine

Question 20

Carbonic anhydrase inhibitor

* end with - zolamide

Answer 20

Aceta-zolamide (old - oral)

Brin-zolamide (new - topical)

Dor-zolamide (new- topical)

Question 21

Carbonic anhydrase CA

Answer 21

Family of enzymes
Extremely rapid enzyme activity
Reversible

Question 22

CA inhibitor

Answer 22

Reduces HCO3- synthesis

⬇️AH production = ⬇️ IOP

Question 23

CA inhibitor (acetazolamide) in kidney

Answer 23

Inhib CA in lumen and proximal tubule of kidney

Reduction in H+ions for NA+ _ H+ exchanges
•hinders Na+ reabsorption and diuresis occurs
•NaHCO3 excretion ^

May result in mild / moderate metabolic acidosis

Question 24

Cholinergic receptors (mus)
M3

Answer 24

M3 : glandular / smooth muscle
(Stimulatory)
• gland secretion or muscle contraction

Question 25

Iris and ANS | Two set of muscles with diff activation

Answer 25

Sphincter pupillae Dilator pupillae

Question 26

Sphincter pupillae

Answer 26

Circular group muscle ⬇️pupil size on contraction M3 receptor of ParaSymNS stimulated In bright light ( protective ) regulate how much light entering eye

Question 27

Dilator pupillae

Answer 27

Radial group ⬆️ size of pupil A1 of adrenergic of sympNS stimulated When in dark (allow to see)

Question 28

Pilocarpine | Not in use

Answer 28

Act on parasymp (cholinergic) M3 • constrict pupil Increase outflow through trabecular meshwork

Question 29

Acute ( angle closure) glaucoma need laser iriditomy : laser create a hole on rim of iris, allow aqueous humour to flow Drugs

Answer 29

* topical pilocarprine plus topical b blocker * iv acetazolamide * diuretics

Question 30

Drugs for eye examinstion | anticholinergic - able to dilate eyes, as block m3 receptor activity on the sphincter pupillae

Answer 30

Atropine (Too long action duration) Tropicamide (6hrs) Cyclopentolate (24hrs)

Question 31

Drugs for eye examination | Sympathomimics- mimic a1 receptor mediated actions , dilate eyes

Answer 31

Phenylephrine Naphazolin Tetrahydrozoline

Question 32

Topical sympathomimetics also cause : Vasoconstriction and decrease congestion of conjunctival blood vessel ⬇️redness

Answer 32

OTC meds Especially Naphzaoline and tetrahydrozoline

Question 33

Sympathmimetics AE

Answer 33

Usually non But concerns with elderly and children; also cardio pts Could cause tachycardia and elevated BP

Question 34

Ocular congestion drugs Same as sympathomimetics

Answer 34

Phenylephrine Naphazoline Tetrahydrozoline

Question 35

Dry eye syndrome drugs

Answer 35

Artifical tears * carmellose * hypromellose