Part Four: Chronic DX - Glaucoma Flashcards
Exam 4 (Final)
Overview of the Eye:
What does the external eye consist of?
sclera
conjunctiva
cornea
Overview of the Eye:
What does the middle portion of the eye consist of?
The middle portion of the eye includes the
iris,
pupil,
lens,
ciliary body
choroid layer
Overview of the Eye:
What does the posterior portion of the eye consist of?
The posterior portion of the eye contains the
vitreous humor
retina
optic nerve
Normal conditions:
What produces the aqueous humor and where is it secreted?
Aqueous humor is produced by the ciliary body & secreted into posterior chamber
Normal conditions:
Aqueous humor is produced by the ciliary body & secreted into posterior chamber
What does this play a role in maintaining?
~ role in maintaining IOP < 20mmHg
Normal conditions:
Aqueous humor is produced by the ciliary body & secreted into posterior chamber
From there, where does it go? Where does it exit?
From there, it circulates around iris –> anterior chamber –> exits thru trabecular meshwork (drain) & canal of Schlemm
Normal conditions:
Aqueous humor is produced by the ciliary body & secreted into posterior chamber
If outflow is impeded from anterior chamber, what will happen?
If outflow impeded from anterior chamber, back-pressure will develop & IOP will rise
Patho of Glaucoma: Glaucoma ~ group of DX
What happens to fluid in the front of the eye? What does this lead to?
Fluid builds up in front part of eye from impaired drainage (clogged drain)
Pressure inside eye rises
Patho of Glaucoma: Glaucoma ~ group of DX
Fluid builds up in front part of eye from impaired drainage (clogged drain)
Pressure inside eye rises- What does this lead to?
↓ peripheral vision
Damage to optic nerve damage
Patho of Glaucoma: Glaucoma ~ group of DX
Common forms (2 types): What are they?
Primary open-angle POAG, more common
Acute angle-closure (narrow-angle)
Patho of Glaucoma
Secondary glaucoma: What is it caused by?
Caused by underlying condition or drugs that increase eye pressure
Patho of Glaucoma
Secondary glaucoma: What meds are used for this?
Meds ~ corticosteroids
Patho of Glaucoma
Secondary glaucoma:
Systemic DX includes what?
~ arteriosclerosis, DM, Htn
Patho of Glaucoma
Ocular HTN: What is this?
↑ IOP, ⍉ optic nerve damage
Patho of Glaucoma
Ocular HTN: How high can pressure be?
IOP may be > 30mmHg but there’s no injury to optic nerve
Patho of Glaucoma
Ocular HTN: Is this glaucoma?
Not glaucoma
There are two major types of glaucoma
What are they?
Primary Open Angle Glaucoma (POAG)
Acute-angle ~ displaced iris, blocks trabecular network
There are two major types of glaucoma
Impeded outflow from anterior chamber ~ ↑ IOP
What kind of glaucoma is this?
Primary Open Angle Glaucoma (POAG)
There are two major types of glaucoma
What is the most common type of glaucoma?
Primary Open Angle Glaucoma (POAG)
There are two major types of glaucoma
POAG ~ clogged drain (most common): Why does this occur?
Resistance to drainage
There are two major types of glaucoma
Primary Open Angle Glaucoma (POAG): What happens to eye pressure, what does this lead to?
Eye pressure ↑ progressive damage to optic nerve
There are two major types of glaucoma
Eye pressure ↑ progressive damage to optic nerve
Risk Factors
↑ IOP (but can develop with normal IOP)
African or South American ancestry
FHX
Advanced age
There are two major types of glaucoma
Eye pressure ↑ progressive damage to optic nerve
What will it EVENTUALLY lead to?
Eventual vision impairment
Painless, insidious occurs over yrs
Vision loss
There are two major types of glaucoma
Eye pressure ↑ progressive damage to optic nerve
Vision loss: How does it occur? When does it occur?
Peripheral –> central visual field
Sx absent until extensive optic nerve damage
There are two major types of glaucoma
Eye pressure ↑ progressive damage to optic nerve
Vision loss:
What must be done for this?
Regular screening
There are two major types of glaucoma
Acute-angle ~ displaced iris, blocks trabecular network
How is it precipitated?
Precipitated by displaced iris –> covers trabecular meshwork
There are two major types of glaucoma
Acute-angle ~ displaced iris, blocks trabecular network
What is blocked?
Drainage angle completely blocked
There are two major types of glaucoma
Acute-angle ~ displaced iris, blocks trabecular network
What is prevented from occuring?
Exit of aqueous humor from ant chamber prevented
There are two major types of glaucoma
Acute-angle ~ displaced iris, blocks trabecular network
What happens to IOP?
IOP increases rapidly to dangerous levels
There are two major types of glaucoma
Acute-angle ~ displaced iris, blocks trabecular network
How does this disease develop?
Develops suddenly, extremely painful
There are two major types of glaucoma
Acute-angle ~ displaced iris, blocks trabecular network
What is this disease considered? What does it lead to?
Medical emergency - ⍉ TX ~ irreversible blindness in 1-2d
There are two major types of glaucoma
Acute-angle ~ displaced iris, blocks trabecular network
What is treatment?
Tx with drops & corrective surgery
There are two major types of glaucoma
Acute-angle ~ displaced iris, blocks trabecular network
What are causes of this?
Trauma
Sudden/prolonged pupil dilation
Comparative Anatomy:
Open Angle Glaucoma: What does it look like?
The angle between the iris and cornea is open, permitting unimpeded outflow of aqueous humor through the canal of Schlemm and trabecular meshwork.
Comparative Anatomy:
Acute Angle Glaucoma: What does it look like?
The angle between the iris and cornea is constricted in angle-closure glaucoma, thereby blocking outflow of aqueous humor through the canal of Schlemm and trabecular meshwork.
Pharmacotherapy (topical):
What is it?
Beta-adrenergic blocking agents
Pharmacotherapy (topical):
Beta-adrenergic blocking agents
Agents (first-line): Include what 2 groups?
NON-selective:
Beta1 Selective:
Pharmacotherapy (topical):
Beta-adrenergic blocking agents
Agents (first-line): NON-selective- what is an example?
NON-selective: timolol
Pharmacotherapy (topical):
Beta-adrenergic blocking agents
Agents (first-line):
Beta1 Selective: What is an example? What is this kind preferred for?
Beta1 Selective: betaxolol (preferred in asthma, COPD – why???)
Pharmacotherapy (topical)
Beta-adrenergic blocking agents: What are they used for?
Used for initial & maintenance tx in open-angle,
ocular htn,
& emergency tx of acute
Pharmacotherapy (topical)
Beta-adrenergic blocking agents: MOA
↓ aqueous humor production
Pharmacotherapy (topical)
Beta-adrenergic blocking agents: MOA
By decreasing aqueous humor production, what it the beta blocker doing?
By decreasing aqueous humor production, beta-blockers help lower eye pressure.
Pharmacotherapy (topical)
Beta-adrenergic blocking agents: MOA
Where do effects occur?
Local effects
Pharmacotherapy (topical)
Beta-adrenergic blocking agents:
Local effects include what?
Transient ocular stinging, conjunctivitis, blurred vision, photophobia, dry eyes
Pharmacotherapy (topical)
Beta-adrenergic blocking agents:
Systemic ADEs possible and what should be monitored?
Bradycardia,
AV block
Bronchospasm
CI: AVB, SB, cardiogenic shock
Monitor pulse
Pharmacotherapy:
What is a another group of drugs?
Prostaglandin analogs
Pharmacotherapy:
Prostaglandin analogs: Latanoprost
How effective is it compared to beta blockers?
Effective as BBs, less SEs
Pharmacotherapy:
Prostaglandin analogs: What is the first line drug?
Latanoprost
Pharmacotherapy
Latanoprost: MOA
What does it do to reduce IOP?
Increases the outflow of aqueous humor through the uveoscleral pathway –> indirectly reduces IOP
Pharmacotherapy
Prostaglandin analogs–> Latanoprost
What is uveosceral pathway?
uvea (includes the iris, ciliary body, and choroid)
and the sclera (the white outer layer of the eye).
Pharmacotherapy
Prostaglandin analogs–> Latanoprost
Increases the outflow of aqueous humor through the uveoscleral pathway –> indirectly reduces IOP
What is this pathways an alternative for?
This pathway is an alternative route for aqueous humor drainage that does not involve the trabecular meshwork.
Pharmacotherapy
Prostaglandin analogs–> Latanoprost
When is this medication administered?
Given in the evening
Pharmacotherapy
Prostaglandin analogs–> Latanoprost
What is a common side effect? Who is it most noticeable in? What happens is medication is stopped?
Harmless brown pigmentation of iris
Most noticeable in light eyes
Stops when d/c’d but does not usually regress
Pharmacotherapy
Prostaglandin analogs–> Latanoprost
What is a side effect that MAY happen? Who is it most noticeable in? What happens is medication is stopped?
May increase eyelid pigmentation
May increase length, thickness, pigmentation of eyelashes
Pharmacotherapy
Prostaglandin analogs–> Latanoprost
What are serious side effects of this drug? (not eye lid or eye color stuff)
Blurred vision, burning stinging
Alpha2-adrenergic agonists
What is the prototype?
Brimonidine (Alphagan P)
Alpha2-adrenergic agonists
Brimonidine (Alphagan P): MOA?
↓ aqueous humor production & ↑ outflow
Alpha2-adrenergic agonists
Brimonidine (Alphagan P): MOA
How does it ↓ aqueous humor production & ↑ outflow?
stimulates alpha receptors found on the blood vessels that supply the ciliary body, causing them to constrict, so it reduces the amount of watery fluid that filters out of the blood vessels to form aqueous humour
Alpha2-adrenergic agonists
Brimonidine (Alphagan P):
What is the dosage?
1 drop three times a day
Alpha2-adrenergic agonists
Brimonidine (Alphagan P):
ADEs
Ophthalmic irritation, dry mouth, engorgement of ocular BVs, local burning, stinging, blurry vision
Can cross BBB & cause drowsiness, fatigue, hypotension, dry mouth
Alpha2-adrenergic agonists
Brimonidine (Alphagan P):
ADEs :Can cross BBB & cause drowsiness, fatigue, hypotension, dry mouth
Why does this happen?
Remember activation of alpha2 receptors in brain decreases sympathetic outflow to BVs & lowers BP
Alpha2-adrenergic agonists
Alpha2 Agonist/BB combo: What is it composed of?
Brimonidine/timolol
Cholinergics (parasympathetic/muscarinic agonist):
What is the prototype?
Pilocarpine
Cholinergics (parasympathetic/muscarinic agonist):
Pilocarpine: MOA?
Miosis due to iris sphincter contraction
Contraction of ciliary muscle
Cholinergics (parasympathetic/muscarinic agonist):
Pilocarpine: Contraction of ciliary muscle- What does this do to focus?
Focuses the lens for near vision
Cholinergics (parasympathetic/muscarinic agonist):
Pilocarpine: Contracting ciliary muscle promotes widening of the spaces within trabecular meshwork, directly reducing IOP
What does this do to aqueous humor outflow?
↑ aqueous humor outflow
Cholinergics (parasympathetic/muscarinic agonist):
Pilocarpine: Contraction of ciliary muscle- What does this promote and lead to?
Contracting ciliary muscle promotes widening of the spaces within trabecular meshwork, directly reducing IOP
Cholinergics (parasympathetic/muscarinic agonist):
Pilocarpine: Contracting ciliary muscle promotes widening of the spaces within trabecular meshwork, directly reducing IOP
What is this good to treat?
Good for acute angle
Cholinergics (parasympathetic/muscarinic agonist):
Pilocarpine: Contracting ciliary muscle promotes widening of the spaces within trabecular meshwork, directly reducing IOP
Good for acute angle: Why?
Pulls iris away from trabecular network removing impediment to outflow
Cholinergics (parasympathetic/muscarinic agonist):
Pilocarpine:
What are ADEs?
Miosis, blurred vision, decreased visual acuity (alters shape of lens), systemic rare
Cholinergics (parasympathetic/muscarinic agonist):
Pilocarpine:
What are rare ADEs?
Rare – sustained contraction of ciliary muscle causes retinal detachment
Carbonic anhydrase inhibitors : How effective? How is this used?
(less effective, adjunct)
Carbonic anhydrase inhibitors :
What is the prototype?
Dorzolamide (trusopt)
Carbonic anhydrase inhibitors :
Dorzolamide (trusopt): MOA
Reduce IOP
↓ aqueous humor production
Carbonic anhydrase inhibitors :
What is the ADRs?
Ocular stinging, bitter taste, conjunctivitis
Carbonic anhydrase inhibitors :
What is Dorzolamide used in combination with?
What would this do?
Greater reduction of IOP
Management of POAG
What is the goal? Is there a cure? How long should you use medicine? What does it do?
Goal: ↓ IOP
⍉ cure, chronic use req.
↓ slow, or stop DX progression
Management of POAG
Drug actions include?
Facilitate aqueous humor outflow
↓ aqueous humor production
Management of POAG
Treatment model: What is preferred? Why?
Ophthalmic route preferred
Systemic ADEs uncommon
Management of POAG
Different MOAs: What may be more effective for some people?
Combo TX may be more effective > mono-TX
Management of POAG
1st line agents include?
Beta-adrenergic blocking agents
Alpha2-adrenergic agonists
Prostaglandin analogs
Management of POAG
2nd line options include?
Cholinergics/cholinesterase inhibitors
Carbonic anhydrase inhibitors
Management of POAG
Procedures last line?
Laser SX
Filtering SX
Drainage implants
Management of Acute-Angle Glaucoma
Drug therapy
Control acute attack
Cholinergics ~ muscarinic agonists
Carbonic anhydrase inhibitors
Beta-adrenergic blockers
Management of Acute-Angle Glaucoma
Drug therapy: What are beta blockers for?
Emergency management
⍉ maintenance
Management of Acute-Angle Glaucoma
Corrective SX:
Iridectomy or laser iridotomy
Alters iris to permit unimpeded outflow of aqueous humor
Intraocular Exam
Mydriatics/cycloplegics
Mydriasis: What does it do?
Mydriasis – blocks muscarinic receptors that promotes iris sphincter contraction
Intraocular Exam
Mydriatics/cycloplegics
Cycloplegia: What does it do?
Cycloplegia – blocks muscarinic receptors that promote contraction of ciliary muscle
Intraocular Exam
Anticholinergics/Muscarinic antagonists:
What kind of drugs are included?
Atropine,
Cyclopentolate,
Homatropine,
Scopolamine,
Tropicamide
Intraocular Exam
Anticholinergics/Muscarinic antagonists:
What do these drugs do?
Dilation of pupil for direct visualization of eye structures
Intraocular Exam
Anticholinergics/Muscarinic antagonists:
Dilation of pupil for direct visualization of eye structures- How does it do this?
Paralyze iris sphincter to prevent reflexive pupil constriction in response to light from scope
Intraocular Exam
Anticholinergics/Muscarinic antagonists:
What are ADEs?
ADEs: Photophobia (prevents pupil from constricting to light), blurry vision from paralysis of ciliary muscle prevents focusing for near vision, precipitation of angle-closure by relaxing iris sphincter
Intraocular Exam
Adrenergic Agonists: What is the prototype?
(phenylephrine)
Intraocular Exam
Adrenergic Agonists (phenylephrine): What does it do?
Also dilate pupils by activating alpha1-adrenergic receptors on the radial (dilator) muscle of iris
Intraocular Exam
Adrenergic Agonists (phenylephrine): What can it be combined with?
Can be combined with anticholinergic
Intraocular Exam
Adrenergic Agonists (phenylephrine): What can it be used for?
Used as aid in intraocular surgery, eye exam
Intraocular Exam
Adrenergic Agonists (phenylephrine): What can it increase?
Increases degree of mydriasis
Intraocular Exam
Adrenergic Agonists (phenylephrine): What are ADEs?
ADEs: AC glaucoma, CV responses
Inserting Eye Drops/Ointment:
What should be done first? What may need to be done?
Wash hands before touching bottle and checking drug label
If needed, wipe eye with moistened gauze to remove exudate
Inserting Eye Drops/Ointment:
How to insert the drops?
Pull lower eyelid down and instill 1 to 2 drops in lower conjunctival sac without touching tip of dropper to eye
Inserting Eye Drops/Ointment:
After inserting the drops, what should be done?
After releasing lid, instruct to keep eye closed for about 1 minute, and slowly rotate eyes to distribute drug
Inserting Eye Drops/Ointment:
How to promote local effectiveness and decrease systemic absorption of drug?
Gently press inner canthus for 2 to 3 minutes to promote local effectiveness and decreases systemic absorption of the drug
Inserting Eye Drops/Ointment:
If instilling more than 1 drug, what should be done?
If instilling more than 1 drug, wait 5-10 min between each dose
When administering ophthalmic ointment
Hold the applicator tube close to the eye while squeezing about an ½ inch ribbon of ointment into the inferior cul-de-sac starting from the inner canthus to the outer eye
Instruct patient to close eyes for about 1 minute
When administering ophthalmic ointment
If administering ophthalmic drops and ointment at the same time, what should be done?
Note: If administering ophthalmic drops and ointment at the same time, administer drops first and then ointment to the eye
