Ophthalmic Diseases - Block 4 Flashcards
What are the types of available optic formulations?
- Solution
- Suspension (shake well)
- Ointment: applied to conjunctival sac or over lid margins -> blurred vision -> no contacts
- Gels: With cap on, invert and shake once to get medication to tip before instilling in the eye
How man mL are in 1 gtt?
0.05 mL
Are ear and eye drops interchangeable?
Eye drops for ear, but not ear drops for eyes
How should you instill eye drops?
- Clean hands
- Remove contacts
- Look up and form pocket in lower eyelid
- Release drop between eye and lower eyelid (don’t touch tip of bottle to eye)
- Close eye
- Nasolacrimal/punctal occlusion (NLO) x 1-3 minutes
What do you do if you are need to instill multiple dropps of the same med? Differnt med?
Same: Wait 5-10 minutees between drops
Differnet: Apply drops 5-10 minutes apart
What is the order of instilling solution and suspension?
Instill solution first then suspension
How can you insert contacts after drops?
15 minutes after
Right eye sig?
OD
Left eye sig?
OS
Both eyes sig?
OU
Drop sig?
gtt
What is glaucoma?
Optic neuropathy characterized by changes in the optic nerve head that is associated with loss of visual sensitivity and field
What are types primary glaucoma?
- Open angle
- ANgle closure:
* with pupillary block
* W/o pupillary block
What is secondary glaucoma?
- Open angle” pretrabecular, trabecular, posttrabecular
- Angle closure:
* w/o pupillary block
* With pupillary block
What is the aqueous humor?
Clear fluid and ultrafiltrate of the serum that fill the chambers of the eye
How is aqueous humor formed?
Ciliary body and epithelium through filtration (pressure) and secretion (osmosis)
What receptors are involved with ciliary epithelium?
Carbonic anahydrate, a- and b adrenergic receptors
What are the receptors involved with the ciliary body?
Increase inflow: b adrenergic agents
Decrease outflow: a2, b, dopamine blocking, carbonic anhydrase inhibitors, melatonin 1 agonist, adenylate cyclase stimulating agents
What is the rate of aqueous humor secretion into the posterior chamber?
2-3 µL/min
What drugs have the greatest effect in lowering IOP?
- Prostaglandin analog (nocturnal IOP)
- Beta blockers
- Carbonic anhydrase inhibitors (nocturnal IOP)
What is our normal IOP?
15.5 mmHg
When is IOP the highest?
At night after falling asleep or at awakening
What is ocular HTN?
Elevated IOP without s/s of glaucoma
What an advantegous way in treating glaucoma patients?
IOP reduction
What is a cup?
Small depression within optic disk
What are the alterations of the optic disk and visual fields from glaucoma?
Optic Disk:
1. Cup-to-disk ratio >0.5
2. Progressive increase in cup size
Visual fields:
1. Peripheral field constriction
2. Blind spots
3. Nasal visual field depression
Drugs that cause glaucoma?
Open angle: corticosteroids, anticholinergics
Closed-angle: anticholinergics, antihistamins, sympathomimetics
What is the difference between OAG and ACG sx?
OAG: none until substantial visual flied loss occurs
ACG: nonsymptomatic or prodromal sx (blurred/hazy vision with halos, HA)
* Acut sx: cloudy, pain, n/v, abdominal pain, diaphoresis
What are the presentations of OAG?
Bilateral, denetically determined
What are the forms of secondary OAG?
Pretrabecular: normal meshwork is covered and doesn’t allow aqueous humor outflow
Trabecular: alterations of meshwork or accumulation of material in intertrabecular spaces
Posttrabecular: Increased episcleral venous BP
What is the classification of ocular HTN?
IOP >22 mmHg
What are the RF of ocular HTN?
- IOP >25
- Cup:disk >0.5
- Central corneal thickness of < 555 μm
- family history of glaucoma, black, Latino/Hispanic ethnicity, severe myopia, and patients with only one eye