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An Urban Experience
WSVA7-0455 OPHTHALMOLOGY
SELECTED OPHTHALMIC DRUGS: INDICATIONS AND CONTRAINDICTIONS
SELECTED OPHTHALMIC DRUGS: INDICATIONS AND CONTRAINDICATIONS Ann R. Strøm, DVM, DACVO
Evidensia Malmö Djursjukhus, Malmö Cypressvägen 11, 213 63 Malmö, Sweden ann.strom@evidensia.se
Introduction
The eye is composed of a variety of tissues that vary greatly, and which organization is critical to vision. Thus, one drugs positive effect on one tissue could negatively affect the neighboring tissue. Treatment strategies towards ocular disease can be especially challenging because some tissues are vascular while some are avascular, and because of the ocular barriers. The
ocular barriers including the cornea and sclera and the blood-ocular barrier, composed of the blood-aqueous barrier at the iris and ciliary body, and the blood-retinal barrier at the choroid and retina, can make target tissues hard to reach in therapeutic levels. When choosing a proper ophthalmic treatment startegy the practitioner must choose a drug and route of administration that allows the drug to penetrate into the target tissue, maintain therapeutic drug levels in the target tissue for a reasonable time, and that has the least severe adverse effects on the target tissue and systemically. The ocular surface facilitates local treatment of certain ophthalmic disease, enabling us to minimize systemic side effects and maximize concentration of medications in ocular tissues. Topically administered medication eventually enters the vascular system via the nasolacrimal system, conjunctiva, aqueous humor, and anterior uvea in minimal quantities and most often without systemic adverse effects. In general, ocular surface disease is most often amenable to topical treatment. However, not all eye disease can be treated via this route. Systemic administration of medication is typically most effective for treatment diseases in the eyelids, orbit or posterior ocular segment. The conjunctiva and anterior uvea can be addressed both via the topical and systemic route.
Dos and don’ts when applying topical ophthalmic drugs:
- Always administer one drop
- Always leave at least 5-10 minutes between drops of a different type
- Always work give least viscous drug first and most viscous drug last
- Two (or more) ointments can be administered simultaneously
- Consider using drops for nasolacrimal intraluminal conditions
- Topical drugs should never be administered by subconjunctival injection
- Drugs required in high concentration in the cornea and conjunctiva are usually are best administered by frequent topical application
- Drugs required in high concentration in vascular components of the eye usually are best administered by a systemic route
- Make sure the drug formulation used facilitates penetration into the target tissue. Many topically applied drugs do not cross the cornea and the blood-ocular barrier prevents many systemically administered drugs from reaching the aqueous or vitreous humors
- Posterior segment disease must be treated via the systemic route
- Do not use ointment formulations on deep ulcers or when a corneal rupture is present or prior to ocular surgery, or following intraocular surgery or if a bandage contact lens is placed as ointments should not enter the eye
- When no deep ulcers are present ointments can be used to increase contact time, provide lubrication, and protect against desiccation
Selected topical ophthalmic drugs: Indications and contraindications
Local Anesthetics (Proparacaine or tetracaine ophthalmic solutions)
Indications/effects: Corneal anesthesia for diagnostic and minor surgical purposes
Contraindications/adverse effects: Not for repeated use. Inhibit corneal epithelialization, toxic to normal corneal epithelium, abolish protective reflexes and increase chance of further injury
Autonomic Drugs
Symphathomimetic agents (phenylephrine ophthalmic solutions)
  42ND WORLD SMALL ANIMAL VETERINARY ASSOCIATION CONGRESS AND FECAVA 23RD EUROCONGRESS
  





































































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