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Two major forms:

Acute Glaucoma

Results when the angle between the

iris and the cornea becomes

narrowed, restricting or blocking the

drainage of aqueous humor through

the trabecular network and the canal

of Schlemn. This causes IOP to

increase suddenly.

It may result from trauma, stress, or

any process that pushes the iris

forward against the inside of the

cornea when there is already an

anatomically shallow anterior orchamber.

It is an acute, painful condition that can cause permanent eye damage within

several hours.

Chronic (open-angle)

Results from the gradual deterioration of the trabecular network that, as in

the acute form, blocks drainage of aqueous humor and causes IOP to

increase.

If untreated, may result in degeneration of the optic nerve and visual fieldloss.

It is the most common form of glaucoma, and its incidence increases with

age.

Genetics and conditions, such as diabetes and hypertension, also play a role.

Assessment:

1. Acute Glaucoma:

Severe pain, occurring in and around the eyesdue to increased IOP; may transitory attacks.

Cloudy, blurred vision; rainbow color aroundlights.

Hazy cornea due to edema; may be profuselacrimation and ciliary injection.

Nausea and vomiting may occur. Pupil is mild-dilated and fixed.

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2. Chronic Glaucoma

Mild, bilateral discomfort (tired feeling in the eyes). Slow loss of peripheral vision central vision remains unimpaired; in later

stages, progressive loss of visual field. Increased IOP causes halos to appear around lights.

Diagnostic Evaluation:

1. Tonometry shows elevated IOP in acute and chronic disease.2. Gonioscopy studies the angle of the anterior chamber of the eye in acute

disease.3. Ophthalmoscopy may show pale optic disk (acute disease) or signs of clipping

and atrophy of the disk (chronic disease). Dilation of the pupil is avoided ifthe anterior of chamber is shallow.

Pharmacologic Interventions:

1. In acute glaucoma, emergency drug management is initiated to decrease eye pressure.

Parasympathomimetics (carbachol, pilocarpine) may be used as miotics tocause the pupil to contract and draw the iris away from the cornea, thusenlarging the angle and allowing aqueous humor to drain.

Carbonic anhydrase inhibitors (acetazolamide, methazolamide), given orallyto depress aqueous humor production.

Beta-adrenergic blockers (betaxolol, timolol), given topically, may reduceaqueous humor or facilitate its drainage.

Hyperosmotics (mannitol, glycerol) increase blood osmolarity and diurese theaqueous humor given I.V.

2. In chronic glaucoma, a combination of miotic agent and carbonic anhydrase inhibitor isusually given.

Surgical Interventions:

1. Surgery is indicated for acute glaucoma if IOP is not maintained within normal limits by

pharmacotherapy and if there is progressive visual field loss with optic nerve damage.2. Types of surgeryfor acute glaucoma include:

a.Peripheral iridectomy Small portion of the iris excised so aqueous humor can bypass pupil.

b. Trabeculectomy part of trabecular meshwork and iris removed.

c. Laser iridectomy - creates multiple incisions in the iris to create openings for aqueous to flow.

3. Types of surgery for chronic glaucoma include:

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a. Laser trabeculoplasty creates multiple surface burns to increase outflow of aqueous humor;

treatment of choice if IOP unresponsive to medical regimen.

b. Iridencleisis opening between anterior chamber and conjunctiva to bypass blockedmeshwork and allow aqueous humor to be absorbed into conjunctival tissues.

c. Cyclodiathermy or cyclocryotherapy super-cooled probe or electrical current used to

interfere with ability to secrete aqueous humor by ciliary body.

d. Corneoscleral trephine (rarely done) a permanent drainage opening is made at the junction

of the cornea and sclera through the anterior chamber.

Nursing Interventions:

1. Monitor for any pain or visual changes.2. Monitor the patients compliance with medications and follow-up care.3. Administer antiemetics as directed to prevent vomiting, which will increase

IOP.4. Administer medications I.V., orally or topically, as directed, and explain the

importance of medications, the proper procedure for administration of drops,and possible adverse reactions.

5. After surgery, elevate head of the bed 30 degrees to promote drainage ofaqueous humor after a trabeculectomy.

6. Administer medications (steroids and cycloplegics) as directed afterperipheral iridectomy to decrease inflammation and to dilate the pupil.

7. Use an eye patch or shield in children for several days to protect the eye; inadults, patch is usually removed within several hours.

8. Alert the patient to avoid prolonged coughing or vomiting, emotional upsetssuch as worry, fear, anger; exertion such as pushing and heavy lifting.

Glaucoma is a disease in which the optic nerve is damaged, leading toprogressive, irreversible loss of vision. It is often, but not always, associatedwith increased pressure of the fluid in the eye.

The nerve damage involves loss of retinal ganglion cells in a characteristicpattern. There are many different sub-types of glaucoma but they can all beconsidered as a type of optic neuropathy. Raised intraocular pressure is asignificant risk factor for developing glaucoma (above 22 mmHg or 2.9 kPa).One person may develop nerve damage at a relatively low pressure, while

another person may have high eyepressure for years and yet never developdamage. Untreated glaucoma leads topermanent damage of the optic nerve andresultant visual field loss, which canprogress to blindness

Overview

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A persons sense of sight is very important to humans. Vision is arguably the most

used of the 5 senses and is one of the primary means that we use to gather

information from our surroundings. The human eye is the organ which gives us the

sense of sight, allowing us to observe and learn more about the surrounding world

than we do with any of the other four senses.

People use their eyes in almost every activity they perform, whether reading,

working, watching television, writing a letter, driving a car, and in countless other

ways. Most people probably would agree that sight is the sense they value more

than all the rest. The eyes are at work from the moment a person is wake up to the

moment he or she closes them to go to sleep.

This special organ takes in tons of information about the world around you

shapes, colors, movements, and more. Then they send the information to your brain

for processing so the brain knows whats going on outside of your body.

Anatomy of the Eye

External and Accessory Structures

The adult eye is a sphere-shaped organ that

measures about 1 inch or 2.5 cm in diameter.

However, only one sixth (1/6) of the eyes

surface can normally be seen and the rest is

enclosed and protected by a cushion of fat and

the walls of the bony orbit.

The accessory structures of the eye are the

following:

Extrinsic eye muscles. The extrinsic muscles of the eye come from the

bones of the orbit and are movable due to broad tendons in the eyes tough

outer surface. There are six extrinsic eye muscles that function to MOVE the

eye in various directions:

1. Superior rectus muscle rotates the eye upward and toward the midline

2. Inferior rectus muscle rotates the eye downward and toward the midline

3. Medial rectus rotates the eye toward the midline

4. Lateral rectus rotates the eye away from the midline

5. Superior oblique rotates the eye downward and away from the midline

6. Inferior oblique rotates the eye upward and away from the midline

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Eyelids. The eyelids protect the eyes anteriorly which meet at the medial

and the lateral corners of the eye. From the border of each eyelid are the

EYELASHES. The eyelashes help filter out foreign matter, including dust and

debris, and prevent it from getting into the eye. Eyelid edges associate with

modified sebaceous glands make up the TARSAL GLANDs. These glands

produce an oily secretion that lubricates the eye. Between the eyelashes,modified sweat glands called ciliary glands are found.