Txtbk Ch 63 Flashcards
What are irrigating solutions composed of?
These solutions have various compositions that include, sodium, K+, mg,Ca, bicarbonate, glucose, and glutathione( substance found in the aqueous humor)
What are most irritating solutions used for?
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.
Name a sterile irrigating solution and tell what it is used for?
Dacriose is used for lid hygiene
What is commonly used to irrigate the corneal surface when chemical burns occur?
Normal saline.
What do lubricants such as artificial tears help alleviate?
They help alleviate corneal irritation, such as dry eye syndrome
What are artificial tears?
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.
Why is absorption of eye drops by the nasolacrimal duct undesirable?
Because of the potential systemic side effects of,ocular medications.
Before the administration of eye drops what does the nurse warn the pt. About?
The nurse warns the patient that blurred vision, stinging, and a burning sensation are symptoms that ordinarily occur after instillation and are temporary.
What should a pt. do if the cannot feel the eye drops when they are instilled?
They may be refrigerated, cold eye drops are easier to detect.
What is glaucoma?
The term glaucoma is used to refer to a group of ocular conditions characterized by optic nerve damage.
What does increased IOP do?
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.
Glaucoma is more prevalent in what age group?
In ppl older than 40.
It is the 3rd most common age related eye disorder.
Is there a cure for glaucoma?
No.
It can only be controlled.
Where does aqueous humor flow?
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.
About 10% of the aqueous humor exits from where?
Exits through the ciliary body into the suprachoroidal space and then drains into the venous circulation of the ciliary body, choroid, and sclera.
Unimpeded outflow of aqueous humor depends on what?
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.
What happens to aqueous humor as we age?
It tends to decrease with age, in systemic diseases such as diabetes, and in ocular inflammatory conditions.
How is IOP determined?
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.
When aqueous fluid production and drainage are in balance the IOP is at what mmHg?
10-21mmHg
What systemic conditions have been assoc with increased IOP?
Diabetes, intraocular conditions such as uveitis and retinal detachment.