The effects of topical diclofenac, topical flurbiprofen, and humidity on corneal sensitivity in normal dogs

Abstract

Neither diclofenac nor flurbiprofen had an effect on corneal sensitivity after multiple-drops or twice-daily dosing for 30 days. Ambient humidity may have an effect on corneal sensitivity measurements, with a longer filament length eliciting a blink response at lower humidity.

Effects of topical flurbiprofen sodium, diclofenac sodium, ketorolac tromethamine and benzalkonium chloride on corneal sensitivity in normal dogs

“…It is possible that the anti-inflammatory action of ketorolac may reduce the irritant effect of benzalkonium chloride on corneal nociceptor fibers. The results of flurbiprofen and diclofenac identified in the current study are somewhat different than the results obtained in a recent study (Dorbandt et al, 2017), and this may be explained, in part, by variations in study design as well as differences in ambient humidity between the two studies. The current study evaluated corneal sensitivity with decreasing increments of 0.25 cm, and this may have allowed the investigators to assess for smaller changes in corneal sensitivity.…”

“…One of the most important differences between the two studies is the ambient humidity. In the current study, ambient humidity values during data collection were 71% to 77%, and it has been shown that humidity may have profound effects on corneal esthesiometry measurements (Dorbandt et al, 2017). In the recent comparable study, ambient humidity ranged from 19% to 44%, which may explain the higher sensitivity values, as the same study found that a lower humidity http://www.openveterinaryjournal.com R. Cantarella et al Open Veterinary Journal, (2017), Vol.…”

“…The aim of this study is to evaluate variations in the corneal sensitivity of dogs after topical application of three different NSAIDS and one preservative agent using a Cochet-Bonnet esthesiometer, which measures the corneal surface sensitivity threshold. In dogs, the accepted criteria for measurement of corneal sensitivity threshold is the degree of corneal stimulation that is required to elicit a blink reflex (Barrett et al, 1991;Stiles et al, 2001;Good et al, 2003;Blocker et al, 2007;Venturi et al, 2016;Dorbandt et al, 2017).…”

“…In the recent comparable study, ambient humidity ranged from 19% to 44%, which may explain the higher sensitivity values, as the same study found that a lower humidity http://www.openveterinaryjournal.com R. Cantarella et al Open Veterinary Journal, (2017), Vol. 7(3): 254-260 ________________________________________________________________________________________________________ 258 results in a higher corneal sensitivity measurement (increased filament length) (Dorbandt et al, 2017). With these results of humidity kept in mind, it can explain why corneal sensitivity values (filament length) obtained in the present study are lower than those obtained in previous studies (Barrett et al, 1991;Good et al, 2003;Dorbandt et al, 2017).…”

“…7(3): 254-260 ________________________________________________________________________________________________________ 258 results in a higher corneal sensitivity measurement (increased filament length) (Dorbandt et al, 2017). With these results of humidity kept in mind, it can explain why corneal sensitivity values (filament length) obtained in the present study are lower than those obtained in previous studies (Barrett et al, 1991;Good et al, 2003;Dorbandt et al, 2017). Although some previous studies in humans and dogs demonstrated the analgesic action of flurbiprofen and ketorolac (Sigle and Nasisse, 2006;Maca et al, 2010), the present study suggests that the ophthalmic application of these two drugs do not promote analgesic activity on corneal nociceptor activity in healthy canine eyes.…”