Which part of the cornea is hydrophilic? which is hydrophobic?
Hydrophilic=Stroma
Hydrophobic=Epithelium & endothelium
What are the pros & cons of opthalmic ointments?
Pro: Longer contact time
Reduced loss through lacrimal drainage
Lubricant
Con: May slow ulcer healing since it is very viscous
What is the contact time for most drugs that are given topically on the eye?
~5 minutes and then drained through the nasal lacrimal ducts
How much of a topically administered drug is lost through the lacrimal drainage?
75%
What are the disadvantages of subconjuntival injections?
Cannot change the med once it is injected
May develop granuloma
No better than freq application of topical meds
NeoPolyBac
Neomycin, Polymixin B and Bacitracin-Ointment
Broad spectrum antibiotics
Topical use for the eye
NeoPolyGram
Neomycin, Polymixin B and Gramidicin-Solution
Broad spectrum antibiotics
Topicaluse for the eye
Aminoglycosides
Mostly gram - (some gram +)
(ex Neomycin, Torbramycin, Amikacin, Gentamicin)
Epitherliotoxic to corneal cells
Which AG is least toxic to the corneal epithelium?
Tobramycin
Neomycin
Usually combined with Polymixin B and either Bacitracin & Gramicidin
Effective against Pseudomonas
Oflaxacin
Quinolone-Only used if they are absolutely NEEDED
Ciprofloxacin
Quinolone-Only used if they are absolutely NEEDED
Cefazolin
Cephalosporin
Well tolerated in the eye
Only use on severe infections!!
Effective against resistant Staphylococcus!!
Which drug is used against resistant Staph?
Cefazolin (Cephalosporin)
Which type of drug is the "super drug" for eyes?
Tetracylcines (Antibiotic, Anti-inflam, Anti-protease, facilitates healing of indolent ulcers)
Which drug is antibiotic, anti-inflam, anti protease and facilitates healing of indolent ulcers?
Tetracyclines
You have a kitten with either a myco of chlamydophila infection. Which drug will you use?
Tetracylcines
T/F Systemic doxycycline treatment will result in doxycycline secretion in the tears
True!
Miconazole
Antifungal
Effective against aspergillus
Which drug is used to treat aspergillus spp in the eye?
Miconazole
Viroconazole
Antifungal
More broad spectrum
Fusarium and aspergillus
If you have a horse with a fungal infection of the eye (you do not know what it is) what is the most broad spectrum choice?
Virconazole
Idoxuridine
Antivirals -Older generation
Used for feline herpes virus
Can be very irrative
Cannot eradicate using these antivirals
Cidofovir
Antiviral
Non irritating (better choice than Idoxuridine)
Is Acyclovir effective against feline herpes?
NO!!!
Which antiviral is the drug of choice for feline herpes?
Cidofovir (less irritating than Idoxuridine)
L-Lysine
Antiviral-Given in combination
May or may not work
Ties up arginine so it is not available for viral replication
Given to cats with herpes or to prevent herpes
Should corticosteroids be used in animals with corneal ulcers?
NO!!! NEVER
Why are steroids contraindicated in corneal ulcers?
They inhibit fibroblasts
They interfere with epitherlial regeneration
They potential proteinases that break down collagen-->Leads to Melting!!
Which corticosteroid forms penetrate the cornea best?
Acetate>Alcohol>Phosphate
Which corticosteroid would you use for intraocular inflammation? extraocular inflammation?
Intraocular=Prenisolone acetate
Extraocular=Dexmethasone sodium phosphate
Acetate>Alcohol>Phosphate as far as entering the cornea goes
T/F NSAIDs may delay healing of corneal ulcers
True-They are not as bad as corticosteroids, but they should be avoided
Flurbiprofen
NSAID-topical
Diclofenac
NSAID-topical
Carprofen (Rimadyl)
NSAID-systemic
Dogs
Meloxicam (metacam)
NSAID-systemic
Cats
Flunixin meglumin (Banamine)
NSAID-systemic
Horses
Piroxicam
NSAID-systemic
Treatment for SCC
Cyclosporine A
Called Optimmune
Immunosuppressive agent
Opthalmic solution
Used for KCS-->Reverses immune-med changes to the lacrimal gland & Stimulates tear production
Used for pannus & episcleritis
Tacrolimus
Immunosuppressive agent
Used for KCS->Reverses immune-med changes to the lacrimal gland & stimulates teat production
Used for pannus & episcleritis
What drugs are used to treat KCS?
Cyclosporine A & Tacrolimus
They reverse immune-mediated changes
They stimulate tear production
How would you treat pannus & episcleritis?
Corticosteroids + Cyclosporine or Tacrolimu s
How are melting ulcers treated?
Antiproteases
Serum
Blood Product
Number 1 Antiprotease
Promotes corneal healing
What is the first drug for treatment of melting ulcers?
Serum
N-acetylcysteine
Antiprotease drug
5%
Used with serum for very severe cases
EDTA
Antiprotease drug
Used on cases of melting ulcers
Sympatholytics (beta blockers)
Anti-glaucoma drugs (Timolol 0.5%)
They are never used alone, except as a preventative
Timolol
Sympatholytic (B-blocker) Anti-glaucoma drug
Never used alone, except as a preventative
Carbonic anhydrase inhibitors
Anti-glaucoma drugs
Topically
Blocks CA
Synergic with B-blockers
(Dorzolamide, Brinzolamide)
Dorzolamide
Anti-glaucoma drugs
Topically
Blocks CA
Synergic with Timilol
Prostaglandin Analogues
Anti-glaucoma drugs
Increases uveroscleral outflow (May cause severe miosis)
MAY work in cats
(Latanoprost & Travoprost)
Latanoprost
Anti-glaucoma drugs
Increases uveroscleral outflow (May cause severe miosis)
MAY work in cats
Travoprost
Anti-glaucoma drugs
Increases uveroscleral outflow (May cause severe miosis)
MAY work in cats
Mannitol
Anti-glaucoma
Osmotic diuretic
1-2g/kg
Parasympatholytics
Control miosis
Paralyses the ciliary body (so it can't cause pain via spasms)
Reduces vascular permeability-->Decreased inflammation
Atropine
Control miosis
Ciliary body stasis-->Helps control pain
Reduction in vascular permeability-->Decreased inflammation
Tropicamide
Parasympatholytic
Not as powerful as Atropine
Faster acting and shorter acting
Control miosis
Ciliary body stasis-->Helps control pain
Reduction in vascular permeability-->Decreased inflammation
Which is the drug of choice for pupil dilation for an exam (best mydriatic)?
Tropicamide (Parasympatholytic)
Phenylephrine
Sympathomimetic
Cuases mydriasis (works best in combination with other drugs)
Controls hemorrhage
Which drug is used for controling ocular hemorrhage?
Phenylephrine
Which drug is used to diagnose Horner's syndrome?
Phenylephrine
T/F Corneal anesthesia comes quicker in conjunctiva because sensory nerve endings are much closer to the surface
True
Why are anesthetics only used for exams and procedures, and not as a treatment?
They are slightly toxic on the cornea
Tetracaine
Doesn't need to be refrigerated!!
Anesthetic
Propacaine
Refrigeration needed!!
Anesthetic