Ophtalmic Disorders EXAM III Flashcards
The most common disorder of the anterior eye
Dry eye(5-15% of the population)
(Women have a higher tendency for dry eye)
What are the causes of dry eye?
-Age/Gender
-Eye defects (e.g., Lacrimal, Lid, Corneal)
-Environmental (e.g., dry air, dust, ACHV)
->Humidifier as remedy
-Diseases (e.g., Sjogren’s syndrome - Rheumatoid Arthritis)
-Contact Lenses
-Medications (Anticholinergics)
-Inflammation
(Prescription for eye treatment: Restasis (Cyclosporin)
What are the three layers that prevent dry eyes?
Lipid layer
Aqueous layer
Mucin layer
How do the layers of the eye affect eye dryness?
-when we blink, tears are distributed and a film is built over the eye
-when tears lack the components to build the eye film, or there are too few tears produced the eye’s tear film breaks down
- Abnormal tear layer
- Reduced lubrication
- Inadequate tear production
Symptoms of dry eyes
-Scratchy, gritty eyes
-red eyes
-desire to rub
-excessive tearing (body’s response to dry eye to keep it moisture)
Treatment for dry eye
Artificial tears (for mild to moderate eye disorders)
Preservative: can be used multiple times, but can cause damage and discomfort over time -> best for short-term, temporary use
Non-preservative: better for patients who need drops multiple times a day; more costly
Non-medicated Ointments
-most viscous
-the more viscous the longer it stays in the eye
-cause blurry vision, may sting
-ointments are used in more serious cases
How to treat mild forms of eye diseases?
-Patient education
-local environmental change
-diet (omega-3-fatty acid diet reduces eye symptoms)
-review medication that may cause symptoms (anticholinergics)
-warm compress
-Artificial tears
How to treat moderate-severe forms of eye diseases?
-Preservative-free artificial tears
-Ointment
-Prescription therapy for dry eye
How to treat severe forms of eye diseases?
Prescription therapy
-if the disease is resistant to treatment -> SURGERY
How do Cellulose ethers and polyvinyl alcohol (PVA) 1.4% work in artificial tears?
Ingredient of Artificial tears
-Stabilize tear film, retards evaporation
-the higher the concentration, the more viscous
Examples of Cellulose ethers
-Hydroxypropyl methylcellulose (HPMC) 0.3-0.8%
-Carboxymethylcellulose (CMC) 0.5-1.0%
How does Povidone (0.6-2%) work in artificial tears?
Ingredient of Artificial tears
Mucin mimetic; Forms hydrophilic layer
and promotes ocular wetting
How do Glycerin 0.5-1.0%, polysorbate 80, and
castor oil work
Ingredient of Artificial tears
Supplements lipid component of tear film
Polyethylene glycol 400, Propylene glycol, Hydroxypropyl guar
Ingredient of Artificial tears
-forms a gel-like environment keeping the
lubricant in contact with the ocular surface
-creates an “ocular shield”
According to a recent meta-study Polyethylene glycols work better than Cellulose ethers in reducing symptoms
True or False
True
Which ingredients are used as preservatives?
-Benzalkonium Chloride (BAK)
-Chlorohexidine
-Thimerosal
-Adverse effects increase with chronic use
What type of artificial tears are appropriate for chronic eye diseases (use for a longer period of time)?
-No preservative
-containing disappearing preservatives (Refresh Liquid gel)
-> Sodium perborate
->Purite (oxychloro complex)
degraded into non-toxic substances