Ophthalmic and anesthetic evaluation of topical 1% tetracaine and 0.5% proparacaine in dogs

Abstract

The aim of this study was to establish the action of 1% tetracaine eye drops in combination with 0.1% phenylephrine in two different posologies and their effects on the eye compared to the 0.5% proparacaine drops in dogs. 22 animals were divided into two groups: TG (11 animals), received 1% tetracaine associated with 0.1% phenylephrine eye drops, one drop instilled in the left eye and two drops, with one-minute interval between each, instilled in the right eye; PG (11 animals) received 0.5% proparacaine eye drops following the same dosage. The average duration of the observed anesthetic action was 25 minutes for tetracaine and 15 minutes for proparacaine. The instillation of two drops increased anesthetic time in five minutes. No changes in intraocular pressure, pupil diameter and tear production was observed. The drops of tetracaine triggered chemosis in four (36.4%) animals. Topical anesthesia with proparacaine eye drops showed no adverse reactions and is thus recommended preferentially.

Corneal anesthesia following application of 0.4% oxybuprocaine hydrochloride ophthalmic solution to normal feline eyes

“…Its corneal anesthetic effects have been established in horses, dogs,, and cats . Tetracaine eye drops are available in form of a 0.5% and 1.0% aqueous solutions or a 0.5% viscous formulation . The depth and duration of their pharmacological effects on corneal sensitivity have been assessed in clinically normal dogs and horses .…”

“…Tetracaine eye drops are available in form of a 0.5% and 1.0% aqueous solutions or a 0.5% viscous formulation . The depth and duration of their pharmacological effects on corneal sensitivity have been assessed in clinically normal dogs and horses . Oxybuprocaine (benoxinate) is a para‐aminobenzoic acid ester developed in the early 50s to serve as a topical anesthetic in human, and which analgesic effects on human cornea have been known since 1955 .…”

“…The longer the thread, the lower the intensity of the pressure, according to the von Frey's principle . Cochet–Bonnet aesthesiometry has become a standard clinical procedure to evaluate and monitor the degree and duration of corneal analgesia following topical application of proparacaine, tetracaine, and nalbuphine eye drops in horses, dogs, and cats …”

Effect of topical 0.5% tetracaine hydrochloride on intraocular pressure in ophthalmologically normal cats

“…6 Parchen et al reported a significant decrease in IOP in dogs 30 mins and 50 mins after tetracaine and proparacaine administration, respectively. 8 In a study by Boillot et al, 5 IOP decreased 1 min after tetracaine administration in the treated eye in dogs. 5 All these studies in dogs showed significant alterations in IOP at different time points.…”

Lacrimal gland excision in male and female mice causes ocular pain and anxiety-like behaviors

“…In contrast, tetracaine had a peak effect at 1 min post application, with palpebral opening returning to baseline values by 10 min. Previous studies comparing these three anesthetics have used ophthalmically normal animals and assessed corneal anesthesia using mechanically-evoked reflexes [39][40][41][42] . In these studies, tetracaine and oxybruprocaine had a similar duration of action, and tetracaine had a slightly longer duration of action when compared to proparacaine.…”