Ophtalmic Disorders EXAM III Flashcards
(46 cards)
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
Dosing Artificial tears
-Start with twice a day
-increase 3-4 times a day
-can be increased, there is no harm bc these are non-medicated (as long as w/o preservatives or disappearing preservatives)
What are the ingredients in non-medicated Ointments?
-White petrolatum 60% (Lubricant)
-Mineral oil 40% (help melt the ointment at body temperature)
-Lanolin (prevents evaporation)
-for moderate-severe disease
Non-medical Ointment dosing
-¼ - ½ inch QHS
-Start at bedtime, due to blurry vision, and eyes are closed
-increase to twice a day based on response
How are Red Eyes (bloodshot eyes) treated?
Artificial tears with decongestants
Ingredients in drugs for red eyes
MOA: localized vasoconstriction, Mixed α1/α2 agonist
-Naphazoline
-Tetrahydrozoline
-Phenylephrine
-Oxymetazoline
selective α2 agonist:
Brimonidine 0.025% (used for Glaucoma with higher dose - prescription)
How do selective α2 agonists affect Conjunctivitis medicamentosa in red-eye?
selective α2 agonists only constrict the venules, it is believed that solely constricting venules ensures blood supply, thereby preventing the body from reacting with dilation to counteract low blood supply (due to artery constriction with α1/α2 constrictor)
–> No rebound congestion
-could be used more than 72 hours