Eyes - Packet and PowerPoint 3

What are the major tenants when dealing with glaucoma?

• Intraocular pressure rises (Cause of fluid buildup)

• Pressure causes damage to optic nerves (axons)

  • Glaucoma is an optic neuropathy produced by increased intraocular pressure

What are the 2 major types of glaucoma?

Open-angle glaucoma

Closed-angle glaucoma (Narrow-angle glaucoma, acute glaucoma)

How long do people have open-angle glaucoma?

Forever it is a chronic condition

How common is open-angle glaucoma?

Most common form of glaucoma (90% of glaucoma)

It is prevalent 65.6 million cases worldwide and 3.4 million cases in the USA

Open-angle glaucoma is an optic neuropathy characterized by what (think what it does to your vision)?

• Progressive peripheral visual field loss

• Followed by central field loss in a typical pattern

What is the process that leads to open-angle glaucoma?

Fluid produced by ciliary body can’t get through either the trabecular meshwork OR Canal of Schlemm because of a blockage, leading to increased pressure

What are some other names of Closed angle glaucoma?

• Narrow angle glaucoma

• Acute glaucoma

How common is closed angle glaucoma?

5% of glaucoma cases

What is a true ophthalmologic emergency when talking about glaucoma?

Closed angle glaucoma

What are the cavities of the eye?

• Posterior cavity

• Anterior cavity

  • Divided into the anterior and posterior chambers

Where is the posterior chamber?

Between the iris and the ciliary body and lens

Where is the anterior chamber?

Extends from the cornea to the iris

What does the ciliary body secrete?

Aqueous humor fluid

What is the path that aqueous humor fluid takes?

Is secreted by the ciliary body

Secreted into the posterior chamber

Flows through the pupil to the anterior chamber

At the base of the anterior chamber, the fluid passes through the Canal of Schlemm (a collecting duct)

It is then returned to the veins of the sclera

What is the pressure created by the fluid within the anterior chamber of the eye where it pushes against the inner surface of the cornea?

Intraocular pressure

What happens when aqueous humor cannot enter the canal of Schlemm?

Fluid pressure rises, distorting soft tissue within the eye

How is open-angle glaucoma described (the quote)?

A silent thief in the night that steals your vision

Why is open-angle glaucoma “a silent thief in the night that steals your vision?”

It develops slowly and goes unnoticed for years (robbing the patient of vision slowly)

Individuals with open-angle _________________________. Some patients are unaware of field loss even when it has progressed to central “tunnel vision.” Thus, open-angle glaucoma is __________________________________________________________.

Individuals with open-angle glaucoma rarely experience symptoms. Some patients are unaware of field loss even when it has progressed to central “tunnel vision.” Thus, open-angle glaucoma is generally detected incidentally on comprehensive ophthalmic examination.

How is open-angle glaucoma generally detected?

Incidentally on comprehensive ophthalmic evaluation

Do patients usually know when they are experiencing open-angle glaucoma?

No they think it is old age and some don’t know it even when it progresses to tunnel vision

What does intraocular pressure buildup damage?

The optic nerve (optic axons)

Why is open-angle glaucoma particularly dangerous?

It can progress gradually and go unnoticed for years

Open-angle glaucoma is a what?

An asymptomatic, progressive optic neuropathy characterized by enlarging optic disc, cupping, and visual field loss

What is open-angle glaucoma characterized by?

• Enlarging optic disc

• Cupping

• Visual field loss

Open-angle glaucoma affects 2% of patients from what population?

Over age 40

Patients experience decreased quality of life and difficulties with what when dealing with open-angle glaucoma?

• Driving (loss of peripheral vision)

• Falls

Why do we need to know the risk factors of open-angle glaucoma?

It is asymptomatic

What are the risk factors for open-angle glaucoma?

• African Americans over the age of 40

  • 3x higher incidence and 6.6 times higher chance of blindness 10 years earlier than caucasians

• Caucasians older that 65

• Family history

  • 2.5 times increased chance

• Diabetes mellitus

• Hypertension

  • Hypertension is connected to increased intraocular pressure

• Myopic

  • Nearsighted people

What is the pathophysiology of open-angle glaucoma?

Microscopic blockage of aqueous humor outflow near the canal of Schlemm

What are the symptoms of open-angle glaucoma?

Patients rarely experience symptoms, but it often affects both eyes simultaneously

It is a modest amount of pressure buildup over time

Not red or painful

Pupil and cornea appear to be within normal limits

What is AAO stand for?

American Academy of Ophthalmology

What are the American Academy of Opthalmology’s recommendations for comprehensive eye examinations for glaucoma?

For adults without risk factors

• Comprehensive eye exam every 5-10 years in patients under 40

• Every 2 years in patients aged 40-54

• Every 1-3 years in patients aged 55-64

• Every 1-2 years in patients 65 and over

For adults with risk factors for glaucoma

• Comprehensive eye exam every 1-2 years in patients under 40

• Every 1-3 years in patients aged 40-54

• Every 1-2 years in patients 55 and over

What is the only way to detect open-angle glaucoma?

Regular eye examinations that include tonometry (painless pressure test)

What physical finding are found in patients with open-angle glaucoma?

• Evidence of increased intraocular pressure over 22 mm Hg

• Retinal changes

  • Pale optic disc

  • Cup enlarges (greater than 50% of the vertical disc diameter)

  • Cupping (a scooped-out appearance of the central cup and nasal displacement of the blood vessels)

• Loss in visual fields

  • Peripheral vision gradually shrinks

How do we measure the pressure of the eye (the test)?

Tonometry

What does tonometry measure?

The force necessary to make an indentation in the eye (pressure of the eye)

What tools are used in tonometry?

Tono-pen

Non-contact device (Air puff machine)

What is cupping when discussing open-angle glaucoma?

A scooped-out appearance of the central cup

Nasal displacement of the blood vessels

What are the results of a Snellen chart for open-angle glaucoma?

Normal (patient often has good visual acuity but poor peripheral field vision)

How can open-angle glaucoma be simulated?

Rolling up a piece of paper and looking through it (you can see straight but not well in the periphery)

What vision diagnostic tool do we use to check vision for open-angle glaucoma?

Automated perimetry

How is the diagnosis of open-angle glaucoma made?

Evidence of intraocular pressure over 22 mm Hg by tonometry

Automated perimetry is an important diagnostic tool that is ________________________________________________________________________________________________________.

Automated perimetry is an important tool that is much more reliable at detecting visual field loss in glaucoma compared with confrontational field testing.

What is better at detecting visual field loss in glaucoma, automated perimetry or confrontational field testing?

Automated perimetry

What does a perimetry test (visual field test) measure?

Measures all areas of eyesight, including peripheral vision

What kind of testing is done using automated perimetry?

Perimetry test (visual field test)

What is the normal intraocular pressure?

8-21 mm Hg

How does a perimetry field test work?

The patient looks inside a bowl-shaped instrument called a perimeter, and the patient will stare at the center of the bowl, light flashes, and the patient presses a button each time they see a flash

What do the dark areas on a perimetry test represent?

Worse vision

What is the best way to monitor glaucoma progression?

Perimetry test

Perimetry test is the best way to monitor what?

Glaucoma (specifically open-angle glaucoma) progression

What does a typical perimetry test look like for a person with open angle progressively (from initial to end-stage)

Starts out with black dot (blind spot) with some blackness in the periphery and then slowly progresses inward till it is all black

Is there a cure for open-angle glaucoma?

No

What is the primary goal of treatment for open-angle glaucoma?

Lowering intraocular pressure which has shown to reduce risk of progression of visual field loss and optic disc change

What therapies do we offer for open-angle therapy?

• Pharmacological therapy

  • Increase aqueous outflow

    • Prostaglandins

      • Latanoprost

      • Bimatoprost

      • Travoprost

    • Cholinergic agonists

      • Acetylcholine (Miochol-E)

      • Carbachol (Miostat)

      • Pilocarpine

    • Alpha adrenergic agonists

      • Brimonidine

  • Decrease aqueous production

    • Alpha adrenergic agonists

      • Brimonidine

    • Beta blockers

      • Levobunolol

      • Carteolol

      • Metipranolol

• Laser therapy (Trabeculoplasty)

What are the problems with pharmacological therapy for open-angle glaucoma?

• Often requires usage of multiple medications

• Medications are expensive for once or twice a day dosing

• Medications are high dosing per day regiments (3-4 x daily) = Less costly-concern more compliance-concern

In what ways does pharmacological therapy fight against open-angle glaucoma?

• Increase aqueous outflow

• Decreasing aqueous production

What medications increase aqueous outflow (I want the family of medication and the name)?

• Prostaglandins

  • Latanoprost

  • Bimatoprost

  • Travoprost

• Cholinergic agonists

  • Acetylcholine (Miochol-E)

  • Carbachol (Miostat)

  • Pilocarpine

• Alpha adrenergic agonists

  • Brimonidine

Name the prostaglandin medications used for increasing aqueous outflow for open-angle glaucoma?

• Latanoprost

• Bimatoprost

• Travoprost

Name the cholinergic agonist medications used for increasing aqueous outflow for open-angle glaucoma?

• Acetylcholine (Miochol-E)

• Carbachol (Miostat)

• Pilocarpine

Name the alpha adrenergic agonist medications used for increasing aqueous outflow and decreasing aqueous production for open-angle glaucoma?

Brimonidine

Name the beta blocker medications used for decreasing aqueous production for open-angle glaucoma?

• Levobunolol

• Carteolol

• Metipranolol

What type of laser therapy do we use to treat open-angle glaucoma?

Trabeculoplasty

What does a trabeculoplasty do?

• Increases aqueous outflow by improving drainage through the trabecular meshwork

• Lasers 80-100 tiny holes into the trabecular meshwork —> The holes cause the burnt tissue to contract —> Pulls the meshwork more open on the adjacent tissue —> Allows for better drainage (treats the open-angle glaucoma)

What is the first line treatment for open-angle glaucoma?

• Pharmacological therapy

• Laser therapy

Is closed-angle glaucoma a medical concern?

It is an OPTHALMOLOGIC EMERGENCY

What can closed-angle glaucoma lead to?

Vision loss and blindness may occur quickly

What is the epidemiology of closed-angle glaucoma?

• Passageway of aqueous outflow is ABRUPTLY blocked by closure of the angle (due to the iris plastering up against the cornea

• When the drainage pathway is narrowed or blocked aqueous humor does not drain

• Leads to increases intraocular pressure and damage to the optic nerve

What are some medications that can cause the pupil to dilate?

• SSRIs (selective serotonin reuptake inhibitors)

• Adderall

What ethnicities are more likely to get open-angle glaucoma?

Those descended from

• African Americans

• Caucasians

What ethnicities are more likely to get closes-angle glaucoma?

Those descended from Asians

What are 2 causes of closed-angle glaucoma?

• Dilation of the pupil may cause the iris to bunch up against the cornea blocking the outflow (causes pressure to build up quickly causing the emergency)

• The iris coming into close opposition (location, position) with the lens when the pupil is in the mid-dilated position preventing aqueous humor from passing from the posterior chamber to the anterior chamber (fluid cannot drain —> pressure builds up —> pressure forces the iris forward blocking the outflow pathway)

What canals are blocked with a closed-angle glaucoma?

Trabecular meshwork and canal of Schlemm

What are the risk factors for closed-angle glaucoma?

Family history of closed-angle glaucoma)

Age over 60

Female

Hyperopia

Patients of Asian descent

Medications

• Psychiatric medication (tricyclic antidepressants)

• Diuretics (Hydrochlorothiazide)

• Beta 2 adrenergic agonist (Albuterol)

• Antihistamines (Tagamet (Cimetidine) and Zantac (Ranitidine))

What medications increase your risk of closed-angle glaucoma?

• Psychiatric medication (tricyclic antidepressants)

• Diuretics (Hydrochlorothiazide)

• Beta 2 adrenergic agonist (Albuterol)

• Antihistamines (Tagamet (Cimetidine) and Zantac (Ranitidine))

What are the symptoms of closed-angle glaucoma?

Painful, red eye

Pain described as intense

Patient sees halos around light

Marked decrease in vision

Significant nausea and vomiting

What is seen in a physical exam of closed-angle glaucoma?

• Unilateral painful red eye

• Extremely high intraocular pressure (as high as 60 mm Hg)

  • Eye ball feels rock hard (normally it is a slightly rubbery conistency)

• The iris becomes paralyzed, causing pupil to be fixed at 4-6 mm (unresponsive to light)

• Cornea appears hazy

• A marked decrease in vision

What is the gold standard method of diagnosis for closed-angle (angle closure) glaucoma?

Gonioscopy

What is a gonioscopy?

Slit lamp is used by an ophthalmologist to visualize the angle

What do we do when someone comes in with closed-angle glaucoma?

Immediate referral to ophthalmologist (must be seen within one hour)

Besides immediately referring the patient to an ophthalmologist how do we treat closed-angle glaucoma?

• Control eye pressure

  • Pilocarpine 4%

    • 2 drops every 5 minutes for 3 doses (usually work within 20-60 minutes)

    • Constriction serves to pull the iris away from the cornea

  • Oral glycerol (70 cc in 70 cc fruit juice) or mannitol IV 2 mg/kg

• Laser peripheral iridotomy

What is the dosage amount for pilocarpine 4% for closed-angle glaucoma?

2 drops every 5 minutes for 3 doses

How long does it take for pilocarpine 4% to work with closed-angle glaucoma?

20-60 minutes

How does pilocarpine 4% work at treating closed-angle glaucoma"?

Causes the pupil to constrict pulling the iris away from the cornea

How do we control eye pressure in the eye for closed-angle glaucoma?

• Pilocarpine 4% (2 drops every 5 minutes for 3 doses)

• Oral glycerol 70 cc in 70 cc fruit juice or mannitol IV 2 mg/kg

What does oral glycerol 70 cc in 70 cc fruit juice and mannitol do?

These are osmotic agents which draw water out of the eye and reduce presssure

What is laser peripheral iridotomy?

Creation of a hole in the peripheral iris through which aqueous humor can flow and reach the angle

What does this show?

Normal fluid making and absorption

What does this show?

Open-angle glaucoma (aqueous outflow by the canal of Schlemm is diminished)

What does this show?

Closed-angle glaucoma (iris abnormally positioned to block aqueous outflow through the anterior chamber)

What does this show?

Non-contact air puff machine

What is this?

Normal inside of eye

What is this?

Open-angle glaucoma (cup-to-disc ratio of this optic nerve is bigger than 0.5)

What is this?

Open-angle glaucoma (cup-to-disc ratio is too big and vessels are hard to fully tract)

Is this a right or left eye?

Right eye

What is this?

Open-angle glaucoma

What diagnostic tool is used to do this test and what is the test called?

Automated perimetry - Diagnostic tool

Perimetry test - The name of the test

What kind of injection is this?

Ciliary injection

What disease is this?

Closed-angle glaucoma (cornea is hazy and red eye)