Glaucoma

Question 1

Definition
A group of ocular diseases in which progressive optic neuropathy
leads to the loss of vision.

dont need to know pathophys

Answer 1

○ Often characterized by an increase in intraocular pressure that causes distinctive changes in the optic disc and loss of retinal nerve fibres
○ Loss of this neural tissue can lead to irreversible loss of visual field usually beginning peripherally, but becoming complete if the disease is unchecked.
○ Can be classified as open angle or closure-angle

Question 2

Classification of Glaucoma

Answer 2

Open Angle Glaucoma
- Caused by partial blockage of the
drainage canal - the angle between the
cornea and iris is still open
slowed drianage

Angle Closure Glaucoma
- caused by a sudden and complete
blockage of the aqueous humor
drainage

Question 3

Comparison of POAG & PACG

Answer 3

see slide 10

Question 4

Primary Open Angle Glaucoma
(POAG)
risk factors

Answer 4

– Elevated IOP
– Advanced age
– Myopia (nearsightedness)
– Black race
– Family history of glaucoma
– Disease (Hypertension, Diabetes,
 Migraines)
– Drug Therapy

Question 5

Primary Angle Closure Glaucoma
(PACG)
risk factors

Answer 5

– Female gender
– Advanced age
– Hyperopia (farsightedness)
– Asian or Caucasion ethnicity
– shallow anterior chamber
– Eye trauma/ injury
– Drug Therapy

Question 6

What statements are false?
a. Closed angle glaucoma usually has no symptoms
b. Intraocular pressure is a non-modifiable risk factor
c. Optic nerve damage and retinal ganglion cell death
leads to visual defects
d. None of the above

Answer 6

A. closed angle glauc has no symptoms

?

Question 7

Risk Factor: Drugs

Answer 7

Primary Open Angle Glaucoma
(POAG)

*● Ophthalmic corticosteroids (high risk)
● Systemic corticosteroids
● Nasal/inhaled corticosteroids
● Ophthalmic anticholinergics
● Succinylcholine
● Vasodilators (low risk)
● Cimetidine (low risk

Primary Angle Closure Glaucoma
(PACG)
● *Topical or systemic anticholinergics
● *Topical or systemic sympathomimetics
● *Antihistamines
●* Tricyclic antidepressants
● *Serotonin-selective reuptake inhibitors
● Venlafaxine
● Topiramate
● Low-potency phenothiazines
● Benzodiazepines (low risk)
● Vasodilators (low risk)
● Monoamine oxidase inhibitors (low risk)
● Topical cholinergics (low risk)

Question 8

Assessment

Answer 8

Ophthalmoscopy
• Optic disk exam (optic nerve head cupping)
• Tonometry – IOP
Note: Screening for ↑IOP alone is not diagnostic for
glaucoma. Up to half of patients with glaucoma have
normal IOPs (<21 mm Hg)
• Perimetry – visual field testing
Screening
• Consider for high-risk populations
(older adults, diabetes)
• Baseline eye exam should begin at age 40 if no other
risk factors for eye disease present

Question 9

Goals of Therapy

Answer 9

1. Lower IOP (a surrogate marker)
2. Prevent or slow down the progression of vision loss
3. Prevent or reduce any associated pain
4. Improve patient’s quality of life

Question 10

Treatment Progression: POAG

Answer 10

Stepwise Approach
 → Add 1st topical drug
 → Add 2nd/3rd topical drug
 → Add systemic drugs
 → Laser therapy
 → Surgery

Question 11

Drug Therapy: POAG (6)

Answer 11

1. Beta adrenergic antagonists
2. Prostaglandin analogues
3. Alpha-2 Adrenergic Agonists
4. Carbonic Anhydrase Inhibitors
5. Cholinergic Agonists
6. Combination Topical Agents

Question 12

1. Beta-Adrenergic Antagonists
   which line?
   safety?
   adherence?

Answer 12

Blockade of the beta-adrenergic
receptors in the ciliary body leads to:
↓ aqueous humour
 production
Examples: Timolol, Betaxolol

First line therapy:
- Efficacy (decreases IOP 20-30%)
- Safety: minimal ocular side effects, but there is potential for systemic side
effects which are associated with beta blockade (e.g.: bradycardia, hypotension, bronchospasm/ shortness of breath)
- Adherence (BID dosing, XR formulations)

Avoid in patients with asthma or severe chronic obstructive pulmonary disease; caution in patients with a history of syncope or bradycardia

AE
Ocular A/Es usually minimal: stinging, dry eyes, conjunctivitis (rare)
Systemic A/Es: bronchospasm, exacerbation of CHF, dyspnea, bradycardia, hypotension, syncope, depression, impotence, altered response to hypoglycemia

Question 13

2. Prostaglandin Analogs
   which line?
   safety?
   adherence?

Answer 13

increases the uveoscleral outflow of
aqueous humour
↑ drainage of aqueous
 humour
Examples: Bimatoprost, Latanoprost,
Travoprost

First line therapy:

• Efficacy (decreases IOP 25%-35%)
• Safety: Generally well tolerated with minimal systemic side effects (fewer than beta blockers)
• conjunctival hyperemia, burning, stinging, itching, iris pigmentation (can darken to brownish), increased eyelash length, headache, flu-like symptoms
• avoid in pregnancy
• Adherence (once daily dosing)

Latanoprost has reduced risk of conjunctival hyperemia
Travoprost is formulated with a non–benzalkonium chloride preservative

Question 14

3. Alpha-2 Adrenergic Agonists
   which line?
   safety?
   adherence?

Answer 14

Suppresses the formation of and increases the uveoscleral outflow of aqueous humour
↓ aqueous humour secretion and
↑ drainage of aqueous humour Examples: brimonidine, apraclonidine

2nd line therapy:
- Efficacy: decreases IOP ~18-27% (less effective than 1st line agents)
- Safety: Allergic type reaction characterized by lid edema, eye discomfort, and
foreign-object sensation, itching, and hyperemia (can occur in up to ~⅓ of
patients on apraclonidine, less often with brimonidine)
- Systemic A/Es: dizziness, fatigue, dry mouth, BP/HR reduction
- Caution in patients with CVD, renal disease, and diabetes
- Adherence: BID and TID dosing

Question 15

4. Carbonic Anhydrase Inhibitors (CAIs)
   which line?
   safety?
   adherence?

Answer 15

Inhibit aqueous production by blocking active
secretion of sodium and bicarbonate ions
from the ciliary body to the aqueous humor
↓ aqueous humour secretion and
Examples:
topical: dorzolamide, brinzolamide,
oral: acetazolamide, methazolamide

Topical CAIs: 2nd line therapy:

• Efficacy: decreases IOP 15-25% (less effective than 1st line agents)
• Safety: *generally well tolerated; local side effects include transient burning andstinging, blurred vision, and rarely, conjunctivitis or photophobia.
• Systemic A/Es: are unusual with topical CAIs
• Due to favorable adverse-effect profile, topical CAIs can be useful alternative monotherapy or adjunctive therapy
• Adherence: BID and TID dosing

Question 16

4. Carbonic Anhydrase Inhibitors
(Systemic)
which line?
safety? 
adherence?

Answer 16

Oral CAIs: 3rd line therapy:
- Efficacy: decreases IOP 25-40% (very effective)
- Safety: frequently produce intolerable adverse effects (systemic acidosis
symptoms such as malaise, anorexia, nausea, depression, decreased libido)
and other A/Es such as kidney stones and frequent urination.
- Adherence: BID to TID dosing

Question 17

5. Cholinergics
   which line?
   safety?
   adherence?

Answer 17

Contracts the ciliary muscle and opens the
trabecular meshwork, thereby promotes the
outflow of aqueous humour
↑ drainage of aqueous humour
Example: Pilocarpine

Topical Cholinergic: 3rd line

• Efficacy: decreases IOP 20-30% (similar to beta blockers)
• Safety: miosis, accommodative spasms, frontal headaches, periorbital pain, eyelid twitching, and retinal tears/ detachments
• Systemic A/Es: diaphoresis, GI upset, urinary frequency, bronchospasm, and heart block.
• Adherence: TID to QID dosing

Poorly tolerated in children and
younger adults.

Question 18

6. Combination Topicals

which line?
safety?
adherence?

Answer 18

Fixed Combination Topicals
Indicated for: patients who require more than 1 agent to adequately reduce IOP
Efficacy: the combination of individual agents are all more effective than their respective individual agents
Safety: combination products reduce cumulative exposure to preservatives and prevent drug washout
Adherence: more convenient and may improve adherence for patients who require
more than 1 agent to adequately reduce IOP

Question 19

Preservatives

Answer 19

Benzalkonium chloride is the most common preservative in eye drops

• Unfortunately, ~ 6% of glaucoma patients are allergic
• Prolonged exposure can result in superficial damage to the ocular surface,leading to irritation, dryness, itching, and burning
• Alternative preservatives/ products have been developed:
• Travatan Z (travoprost): an ionic buffer preservative
• Ibza (travoprost): POLYQUAD preservative
• Alphagan P (briminodine): purite preservative
• Monoprost (latanoprost): single use ampoules, preservative free
• Trusopt (dorzolamide): single use ampoules, preservative free

Question 20

Non-Pharm Therapies

Answer 20

● Lifestyle modifications have not been shown to alter the outcome of the
disease. Aerobic exercise can lower IOP modestly in some patients with glaucoma.
● Laser or surgical procedures are treatment options if drug therapy is
unsuccessful or not tolerated by the patient

Question 21

Monitoring and Targets

Poor Response?

Answer 21

IOP: ↓ of >20% from baseline depending on severity
Disk cupping: <0.5
Perimetry: minimal vision loss

• Check adherence
• Assess technique
• Monitor for side effects
• Change to or add another agent

Question 22

Laser/ Surgery

Answer 22

Laser Trabeculoplasty

• Open-angle glaucoma
• Laser is applied to trabecular meshwork (drainage system).
• First line for elderly, poor adherence, or POAG. Effect is short term (2yr)

Iridectomy

• angle-closure glaucoma
• Used in affected eye and prophylactically in other ey

Question 23

Cannabis?

Answer 23

The COS (Canadian Ophthalmological Society) does NOT support the use of
cannabis (marijuana) for the treatment of glaucoma7
- Has short duration of action and undesirable psychotropic and other systemic side effects.
- Regulation of IOP by THC and CBD is complex and not fully understood
- Other more effective and less harmful treatments exist.

Question 24

Acute Closure Glaucoma (PACG)

types of tx used

Answer 24

Goal of initial treatment: rapid reduction of IOP 3, 7
- Aggressive medical treatment is used until an iridectomy is performed
- Pilocarpine 1% - 4% gtts q5min for 4-6 doses
- Acetazolamide 250 mg p.o. or 500 mg injectable preparation
- Secretory inhibitors (Beta blockers, a2-agonists, topical CAIs)
- Hyperosmotic agents (Mannitol 15%, 20%, or 25%:1.5 -2 g/kg infused
IV over 30-60 min)
- Hypertonic saline 3%: 3ml/kg IV over 20-30min
Surgical intervention (iridectomy or iridotomy) must be performed before the iris
and outflow channel become permanently closed.

Question 25

Topical Agents Summary

Answer 25

Beta-blockers + ++ (betaxolol) Stinging upon contact, dry eyes, conjunctivitis, allergies Prostaglandin analogues ++ Blurred vision, burning, stinging, conjunctival hyperemia, foreign body sensation, itching, iris pigmentation, eyelash thickening Adrenergic agonists ++++ Hyperemia (“bloody eye”), pruritus, tearing, ocular discomfort, foreign body sensation, eyelid edema, conjunctivitis Carbonic Anhydrase Inhibitors + (dorzolamide) Burning, stinging, conjunctivitis, eyelid inflammation, itching, and irritation Cholinergics +++ Myopia, miosis, reduced night vision, blurry visio