Txtbk Ch 63

Question 0

What are irrigating solutions composed of?

Answer 0

These solutions have various compositions that include, sodium, K+, mg,Ca, bicarbonate, glucose, and glutathione( substance found in the aqueous humor)

Question 1

What are most irritating solutions used for?

Answer 1

Most irritating solutions are used to clean the external lids to maintain lid hygiene, to irrigate the external corneal surface to regain normal pH ( chemical burns), to irrigate the corneal surface to eliminate debris, or to inflate the globe intraoperatively.

Question 2

Name a sterile irrigating solution and tell what it is used for?

Answer 2

Dacriose is used for lid hygiene

Question 3

What is commonly used to irrigate the corneal surface when chemical burns occur?

Answer 3

Normal saline.

Question 4

What do lubricants such as artificial tears help alleviate?

Answer 4

They help alleviate corneal irritation, such as dry eye syndrome

Question 5

What are artificial tears?

Answer 5

Artificial tears are topical preparations of carboxymethylcellulose or hydrooxypropyl methyl cellulose that are prepared as eye drop solutions, ointments or ocular inserts( inserted in the lower conjunctival cul- de-sac once each day. The eye drops can be instilled as often as every hr, depending on the severity of symptoms.

Question 6

Why is absorption of eye drops by the nasolacrimal duct undesirable?

Answer 6

Because of the potential systemic side effects of,ocular medications.

Question 7

Before the administration of eye drops what does the nurse warn the pt. About?

Answer 7

The nurse warns the patient that blurred vision, stinging, and a burning sensation are symptoms that ordinarily occur after instillation and are temporary.

Question 8

What should a pt. do if the cannot feel the eye drops when they are instilled?

Answer 8

They may be refrigerated, cold eye drops are easier to detect.

Question 9

What is glaucoma?

Answer 9

The term glaucoma is used to refer to a group of ocular conditions characterized by optic nerve damage.

Question 10

What does increased IOP do?

Answer 10

IOP damages the optic nerve and nerve fiber layer, the degree of harm is highly variable.
The optic nerve damage Is related to the IOP caused by congestion of aqueous humor in the eye.

Question 11

Glaucoma is more prevalent in what age group?

Answer 11

In ppl older than 40.

It is the 3rd most common age related eye disorder.

Question 12

Is there a cure for glaucoma?

Answer 12

No.

It can only be controlled.

Question 13

Where does aqueous humor flow?

Answer 13

It flows between the iris and the lens, nourishing the cornea and the lens.
90% of the fluid then flows out of the anterior chamber, draining through the spongy trabecular mesh work of the canal of Schlemm and the episcleral veins.

Question 14

About 10% of the aqueous humor exits from where?

Answer 14

Exits through the ciliary body into the suprachoroidal space and then drains into the venous circulation of the ciliary body, choroid, and sclera.

Question 15

Unimpeded outflow of aqueous humor depends on what?

Answer 15

On an intact drainage system and an open angle ( about 45 degrees) between the iris and cornea.
** a narrower angle places the iris closer to the trabecular mesh work diminishing the angle.

Question 16

What happens to aqueous humor as we age?

Answer 16

It tends to decrease with age, in systemic diseases such as diabetes, and in ocular inflammatory conditions.

Question 17

How is IOP determined?

Answer 17

It is determined by the rate of aqueous production, the resistance encountered by as the aqueous humor flows out of the passages, and the venous pressure of the episcleral veins that drain into the anterior ciliary vein.

Question 18

When aqueous fluid production and drainage are in balance the IOP is at what mmHg?

Answer 18

10-21mmHg

Question 19

What systemic conditions have been assoc with increased IOP?

Answer 19

Diabetes, intraocular conditions such as uveitis and retinal detachment.

Question 20

What are the 2 theories that suggest how IOP damages the optic nerve?

Answer 20

1.) the direct mechanical theory- suggests that high IOP damages the retinal layer as it passes thru the optic nerve head.
2.) the indirect ischemic theory- suggest that high IOP compresses the microcirculation in the optic nerve head, resulting in cell injury and death.
Some glaucoma appears as exclusively mechanics. And some are exclusively ischemic types. Typically most cases are both.

Question 21

What are the clinical forms of glaucoma?

Answer 21

Open -angle glaucoma
Angle closure glaucoma
Congenital glaucoma
And glaucoma assoc with other conditions such as developmental anomalies or corticosteroid use.

Question 22

What types of examinations are used in glaucoma?

Answer 22

Tonometry; to measure the IOP
opthalmoscopy; to inspect the optic nerve
Central fied testing

Question 23

What are the changes in the optic nerve related to glaucoma?

Answer 23

Pallor and cupping of the optic nerve disc.
The pallor of the optic nerve is caused by a lack of blood supply
Cupping is characterized by exaggerated bending of the blood vessels as they cross the optic disc, resulting in a enlarged optic disc that appears more bask like compared with a normal cup.

Question 24

What is the progression of cupping caused by?

Answer 24

It is caused by the gradual loss of retinal nerve fibers and the loss of blood supply

Question 25

As optic nerve damage increases, what happens?

Answer 25

Visual perception decreases.

Question 26

Open angle glaucoma

Answer 26

usually bilateral but one eye may be more severely affected than the other. In all 3 types of open angle glaucoma, the anterior chamber is open and appears normal.

Question 27

What are the three types of open angle glaucoma?

Answer 27

1. ) Primary open angle glaucoma (POAG) 2. ) normal tension glaucoma 3. ) ocular hypertension

Question 28

What is POAG?

Answer 28

Primary open angle glaucoma; Optic nerve damage, visual field defects, IOP above 21mmHg. May have fluctuations IOP's. Usually no symptoms, but possible ocular pain, headache and halos.

Question 29

What is treatment of POAG?

Answer 29

If medical treatment is unsuccessful, LT can decrease IOP by 20%. Glaucoma filtering surgery if continued optic nerve damage despite medication therapy and LT.

Question 30

What is ocular hypertension?

Answer 30

Elevated IOP. Possible ocular pain or headache

Question 31

What is treatment for ocular hypertension?

Answer 31

Treatment is similar to POAG; however the best management for normal tension glaucoma management is yet to be established. Goal is to lower the IOP by at least 30%

Question 32

What is normal tension glaucoma?

Answer 32

IOP pressure less than 21mmHg. | Optic nerve damage, visual field defects

Question 33

What is angle closure glaucoma?

Answer 33

(pupillary block) Obstruction in aqueous humor outflow due to the complete or partial closure of the angle from the forward shift of the peripheral iris to the trabecula. The obstruction results in increased IOP.

Question 34

Name the 3 types of angle closure glaucoma

Answer 34

1. ) Acute angle closure glaucoma 2. ) subacute angle closure glaucoma 3. ) chronic angle closure glaucoma

Question 35

What is acute angle closure glaucoma?

Answer 35

Rapidly progressive visual impairment, periocular pain, conjunctival hyperemia, and congestion. Pain may be assoc with nausea, vomiting, bradycardia, and profuse sweating. Reduced central vision acuity, severely elevated IOP, corneal edema. Pupil is vertically oval, fixed in a semidilated position and unread rice to light and accommodation.

Question 36

What is treatment for acute angle closure angle glaucoma?

Answer 36

OCULAR EMERGENCY administration of hyperosmotics, acetazolamide, and topical ocular hypotensive agents such as pilocarpine and beta blockers ( betacolol) Possible laser incision in the iris (iridotomy) to release blocked aqueous and reduced IOP. other eye is also treated with pilocarpine eye drops and or surgical management to avoid a similar spontaneous attack.

Question 37

What is subacute angle closure glaucoma?

Answer 37

Transient blurring of vision, halos around lights; temporal headache and or ocular pain Pupil may be semidilated.

Question 38

What is treatment of subacute angle closure glaucoma?

Answer 38

Prophylactic peripheral laser iridotomy | Can lead to acute chronic angle closure glaucoma if untreated

Question 39

What is chronic angle closure glaucoma?

Answer 39

Progression of glaucomatous cupping and significant visual field loss. IOP may be normal or elevated; ocular pain and headache Treatment is similar to POAG which includes laser iridotomy and medications.

Question 40

What is the aim of all glaucoma treatment?

Answer 40

To prevent optic nerve damage

Question 41

What are miotics?

Answer 41

Medications that cause pupillary constriction

Question 42

What ocular meds are used to treat glaucoma?

Answer 42

Miotics, beta blockers, alpha2 agonists, carbonic anhydrase inhibitors and prostaglandins.

Question 43

What does cholinergics do in regards to the eye?

Answer 43

Cholinergics( miotics) increase the outflow of the aqueous humor by affecting ciliary muscle contraction and pupil constriction , allowing flow thru a larger opening between the iris and the trabecular meshwork.

Question 44

What decreases aqueous production?

Answer 44

Beta blockers and carbonic anhydrase inhibitors

Question 45

What reduces IOP

Answer 45

Prostaglandin analogues reduce IOP by increasing aqueous humor outflow.

Question 46

Peripheral neuropathy (disorder of the nervous system)

Answer 46

Is a disorder affecting the peripheral motor and sensory nerves.

Question 47

How is peripheral neuropathy characterized?

Answer 47

By bilateral and symmetric disturbance of function, usually beginning in the hands and feet. Most common cause I'd diabetes with poor glycemic control.

Question 48

What are the major symptoms of peripheral nerve disorders

Answer 48

Loss of sensation, muscle atrophy, weakness, diminished reflexes, pain and paresthesia of the extremities.

Question 49

How are peripheral nerve disorders diagnosed

Answer 49

By history, physical examination, and electrodiagnostic studies such as EEG.

Question 50

What is mononeuropathy?

Answer 50

Is limited to a single peripheral nerve and its branches. It arises when The trunk of the nerve is compressed or entrapped, as in carpal tunnel, traumatized, as when bruised by a blow, or overstretched as in joint dislocation.

Question 51

What is treatment of mononeuropathy

Answer 51

Remove the cause( freeing the compressed nerve) Local corticosteroid injections may reduce inflammation and the pressure on the nerve. Aspirin or codeine may be us to relieve pain Chronic pain Can be treated with neuropathic pain medications such as gabapentin.