Comparison Of Ocular Effects After Use Of Topical Eye Drops Versus Use Of The WhisperTM Topical Drug Applicator

Abstract

Purpose: : To compare the mydriatic, mitotic, and intraocular pressure (IOP) effects of topical tropicamide and latanoprost when delivered as an eye drop versus delivery of the same medication via the Whisper^TM device.

Methods: : Six adult, female beagles were used in this study. With at least 1 week washout between treatments, each dog received topical 1% tropicamide HCl (Bausch & Lomb Inc., Tampa, FL) or 0.005% latanoprost (Greenstone LLC, Peapack, NJ) delivered as a single eye drop (via the commercial bottle) or in a separate study, via a single application using the Whisper^TM device (Corinthian Ophthalmic, Inc.) in the right eye while receiving balanced salt solution (BSS, Alcon Laboratories, Fort Worth, TX) in the left eye using the same application method. Pupil diameter (PD) (tropicamide and latanoprost) using a digital pupilometer (VIP^TM 200, Neuroptics, Irvine, CA) and IOP (latanoprost only) using a TonoVet tonometer (Icare, Espoo, Finland) were measured in both eyes at -1, 0, 0.5, 1, 2, 3, 4, 6, and 8 hours after topical application.

Results: : Eyes receiving topical tropicamide via eye drops or Whisper^TM device had significantly greater PD (P<0.01) than those receiving BSS from 30 minutes to 6 hours after application. Eyes receiving topical latanoprost via eye drops or Whisper^TM device had significantly smaller (P<0.0001) PD from 30 minutes to 8 hours after application and significantly lower (P<0.001) IOP from 1 to 6 hours after application compared to eyes receiving BSS. There were no significant differences in PD in eyes treated with tropicamide by eye drops or by the Whisper^TM device through 6 hours after treatment. Eyes treated with latanoprost via the Whisper^TM device had significantly lower IOP 1 hour (P=0.049) after treatment compared to IOP of eye drop latanoprost. IOP was not significantly different in eyes treated with latanoprost by either method at times 2, 3, and 4 hours after treatment, but IOP was significantly lower (P=0.048) in eyes treated with latanoprost eye drops compared to the Whisper^TM latanoprost at 6 and 8 hours after treatment.

Conclusions: : Drugs delivered via the Whisper^TM device, an innovative approach to application of topical ocular medications, induce similar ocular effects compared to traditional eye drops when using 2 common ocular medications in the dog. Furthermore, the latanoprost IOP data suggests that the Whisper^TM device may induce a more rapid onset of effect compared to the same drug administered via an eye drop. These results strongly support the further development of this innovative device for application of topical ocular medications.

Keywords: drug toxicity/drug effects • intraocular pressure • pupil