dyes and anesthetics

Fluorescein Sodium (NaFl)

• water soluble “indicator dye”

• works by pooling in defects of ocular surface

• DOES NOT penetrate intact epithelium and is NOT taken up by healthy epithelial cells

• administered with strips because very prone to contamination when in solution, also injectable if want to see FANG

why would we use fluorescein sodium?

• evaluation of ocular surface (epi defects)

• TBUT

• seidel’s sign (to see if open globe injury)

• tonometry

• GP lens assessment

• FANG

Rose Bengal

• first vital dye → no pooling→ actually stains

• stains compromised epi cells of cornea and conj, as well as mucus (not missing cells)

• administered via strips

• stings and burns when used

why do we use Rose Bengal?

• dry eye (stains compromised cells from lack of protective tear layer)

• filamentary keratitis (stains mucus that form corneal filaments in advanced dry eye)

• identification of terminal end bulbs on dendrites in Herpes Simplex Keratitis (stain the necrotizing cells at edge of ulcer)

Lissamine Green

• new formulated vital dye

• stains dead and devitalized corneal and conj cells and stains mucus

• more tolerable for patient but not as great for doctors to see/evaluate

• administer via strips

what do we use lissamine green for?

dry eye

topical ocular anesthetics

• reversible blockers of Na+ channels which increase sensory nerve excitation thresholds

• cause temporary, reversible anesthesia without loss of conciousness

• used for. diagnostic purposes only DO NOT RX

what do we use topical ocular anesthetics for?

DIAGNOSIS ONLY

• tonometry

• pachymetry

• gonioscopy

• foreign body removal

• punctal plugs

• lacrimal irrigation

what are the side effects of topical ocular anesthetics?

short term

• stinging, redness, rare immediate allergic diffuse epithelial keratitis

Long term

• prolonged/excessive use can impair wound healing and can lead to sloughing of corneal epithelium

what structural category do most topical local anesthetics fall into?

esters

what structural category do all injectable local anesthetics and topical lidocaine fall into?

amides

proparacaine

• least sting and allergy potential of all topical anesthetics

• most commonly used and most tolerated

tetracaine

• greatest stinging, corneal compromise, and allergic potential of all topical anesthetics

• rarely used

benoxinate

• only available in combo with fluorescein, has bactericidal properties that help combat contamination of liquid fluorescein

• lowest allergy potential and least corneal reactivity of all topical anesthetics

• stinging is mid

Akten (3.5% lidocaine gel)

• only amide available in topical formulation

• provides longer lasting and deeper anesthesia

• used for pre-op, special procedures (forced duction testing, FB removal if large/deep/multiple), or if allergy to all ester anesthetics

Iheezo (3% chloroprocaine gel)

• preservative free, single use applicator

• provides longer lasting and deeper anesthesia

• used for cataract surgery

• can cause mydriasis

should we use anesthetics when trying to obtain a culture? Why or why not?

no, if possible try to obtain culture without anesthetizing becaues all anesthetics exhibit some antibacterial properties so when culturing it could end up killing the bacteria you are trying to culture

injectable lidocaine

• used for lid procedures, intracameral injection during cataract surgery, and retrobulbar injection for cataract surgery

• also combo with epinephrine to induce vasoconstriction to

  • reduce bleeding

  • limit systemic side effects

  • increase duration of action/maintain drug at site (enhance localized effects)