Ocular Disease 2 Second Quiz (Summer)

Intraocular pressure (IOP)

is the fluid pressure of the eye

IOP

this exists as a fine-tuned equilibrium between the production and drainage of aqueous humor

Aqueous humor

This is produced by the ciliary epithelium of the iris ciliary body

posterior chamber

Aqueous humor accumulates in the?

anterior chamber

Aqueous humor flows through the pupil into the?

one of three routes

The aqueous humor then exits the anterior chamber via

1st. Route (vast majority)

Aqueous humor then exits the anterior chamber via one of three routes:

Trabecular meshwork at the angle of the anterior chamber and into the Schlemm canal where it enters episcleral veins

2nd Route: (small amount)

Aqueous humor then exits the anterior chamber via one of three routes:

Passes into the suprachoroidal space and enters venous circulation in the ciliary body, choroid, and sclera

3rd Route (even smaller amount)

Aqueous humor then exits the anterior chamber via one of three routes:

transits through the iris and back into the posterior chamber

Homeostatic mechanism

Aqueous humor mechanism which maintains intraocular pressure

Sympathetic nervous system

This influences the secretion of aqueous

beta-2 receptors

increased secretion for aqueous humor

alpha-2 receptors

decreased secretion for aqueous humor

Glaucoma

is a group of eye disorders that lead to progressive damage to the optic nerve.

nerve tissue

Glaucoma is characterized by loss of what which results in vision loss

optic nerve

In glaucoma the most common form of what damage leading to vision loss

front

In glaucoma fluid builds up where in part of the eye.

optic nerve

In glaucoma this extra fluid puts pressure on the eye, gradually damaging the?

Open-angle glaucoma

most common form of glaucoma

90 percent

Open-angle glaucoma accounting for at least how many of all glaucoma cases

drainage canals

Open-angle glaucoma is caused by the slow clogging of the what, resulting in increased eye pressure

iris and cornea

Open-angle glaucoma has a wide and open angle between the?

Develops slowly and is a lifelong condition

How does open angle glaucoma develop?

Has symptoms and damage that are not noticed

Can open angle glaucoma be noticed?

“Open-angle”

This term means that the angle where the iris meets the cornea is as wide and open

• High eye pressure

• Family history of glaucoma

• Age 40 and older for African Americans

Open-angle glaucoma 3 strong risk factors:

• High myopia (very severe nearsighted ness)

• Diabetes

• Eye surgery or injury

• High blood pressure

• Use of corticosteroids

Open-angle glaucoma 5 Potential risk factors include:

• Gradual loss of peripheral vision

• Tunnel vision in the advanced stages

Open-angle glaucoma 2 Symptoms:

Angle-closure glaucoma

- a less common form of glaucoma

- Caused by blocked drainage canals

- Has a closed or narrow angle between the iris and cornea

closes or becomes blocked

Angle-closure glaucoma occurs when the drainage angle in the eye (formed by the cornea and the iris) becomes what?

the iris and the cornea

In Angle-closure glaucoma with age, the lens in the eye becomes larger, pushing the iris forward and narrowing the space between which structures?

Yes, it demands immediate medical attention:

• Intense pain in your eye

• Nausea

• Red eyes

• Blurred vision

Is angle-closure glaucoma a Medical emergency?

• Age 40 and older

• Family history of glaucoma

• Farsightedness

• Eye injury or eye surgery

• East Asian

Angle-closure glaucoma 5 Risk Factors

• Severe eye pain

• Nausea and vomiting

• Sudden onset of visual disturbance (often in low light)

• Blurred vision

• Halos around lights

• Reddening of the eye

Angle-closure glaucoma 6 Symptoms:

Low-tension glaucoma

- Also known as normal tension glaucoma

- Rare form of glaucoma in which eye pressure is not higher but still causes damage to the optic nerve

• abnormally sensitive optice nerve

• low blood supply to the optic nerve

Low-tension glaucoma may have the following:

• Cardiovascular disease

• Family history of glaucoma

• Low eye pressure

Low-tension glaucoma 3 Risk Factors

Congenital Glaucoma

Occurs in babies when there is incorrect or incomplete development of the eye's drainage canals during the prenatal period

inherited

Congenital Glaucoma is a rare condition that may be

• Buphthalmos

• Haab striae (breaks in Descemet's membrane)

• Epiphora (tearing)

• Cloudiness in the cornea

• Photosensitivity

Congenital Glaucoma The child may have these 5:

Secondary glaucoma

Type of Glaucoma that arises from these such as:

1. Eye injury/trauma

2. Inflammation

3. Steroid use

4. Advanced cases of cataract or diabetes

5. Eye surgery

Pigmentary glaucoma

- This is a type of open-angle glaucoma that typically develops during early or middle adulthood

- It involves changes in the pigment cells that give color to the iris

- Cells build up in the channels that drain fluid from the eye, they can affect the normal flow of fluids in the eye

Traumatic glaucoma

- Caused by injuries that “bruise” the eye (called blunt trauma) and injuries that penetrate the eye

- causes bleeding inside the eye

- excess amount of blood, plasma and debris can accumulate and clog the drainage system

Exfoliative Glaucoma

- Also called pseudoexfoliative glaucoma

- Occurs when a flaky, dandruff-like material peels off the outer layer of the crystalline lens

- The material collects in the angle between the cornea and iris and can clog the drainage system of the eye

Neovascular Glaucoma

- caused by the abnormal formation of new blood vessels on the iris and over the eye's drainage channels.

- always associated with other abnormalities, most often diabetes

- new blood vessels block the eye’s fluid from exiting through the trabecular meshwork

Uveitic glaucoma

- Infections of the uvea (uveitis) may follow an injury,

- result from bacteria or a virus

- occur in association with autoimmune or inflammatory conditions

- infection can produce enough swelling that slows the eye’s natural drainage and elevate IOP

Steroids

If these are used in treating Uveitic glaucoma, then they can also increase IOP

22mm Hg

Glaucoma clinical signs have IOP Greater than

26-30 mm Hg

In glaucoma patients developing visual field loss in creases rapidly, most notably at pressures higher than

Cupping

In glaucoma this is where increased pressure in the eye and/or loss of blood flow to the optic nerve, these nerve fibers begin to die.

greater than 0.6 (sixtenths)

A cup to disc ratio of how much is generally considered to be suspicious for glaucoma?

Disc hemorrhage (Drance / splinter hemorrhages)

In glaucoma this is a sign of trouble, indicating that the disease is active and progression is likely

splinter hemorrhages

Disc hemorrhage is sometimes called this because they look like splinters running parallel to the nerve fibers in the nerve fiber layer