Effects of topical 1% cyclopentolate hydrochloride on quantitative pupillometry measurements, tear production and intraocular pressure in healthy horses.
Abstract: To evaluate the effect of topical cyclopentolate hydrochloride (CH) on quantitative pupillometric readings (PR), tear production (TP), and intraocular pressure (IOP) in healthy horses. Methods: Fourteen client-owned horses. Methods: In a two-phase design study, each animal received 1% CH ophthalmic solution in the left eye [treated] and 0.9% NaCl in the right eye [control] (0.2 mL each). In the first phase (n = 7), TP, IOP, and PR assessment was performed by Schirmer tear test I, rebound tonometry and static pupillometry, at 1, 8, 24, 48, 72, 96, 120, 148, 172, and 196-hours post-instillation. In the second phase (n = 7), plateau mydriasis was evaluated by assessing PR hourly for 8 hours post-instillation. For PR assessment, pupil area (PA), vertical diameter (VPD), and horizontal diameter (HPD) were recorded. All pupillometries were obtained in a room with fixed light intensity (45-60 lux). Statistical analysis was performed by generalized estimating equations method for the effect on parameters over time. Results: After topical CH, significant differences in pupil dilation were seen from 1 to 172 hours for VPD and from 8 to 24 hours for PA, without significant differences on HPD over time. In the second phase, plateau PA and VPD were reached at 3 hours, while plateau HPD at 2 hours. No significant effects were detected on TP and IOP in both eyes at any time, nor on PR of the nontreated eyes. Conclusions: Topical 1% cyclopentolate hydrochloride could be considered an effective and safe option when a mydriatic/cycloplegic drug is needed in horses.
© 2020 American College of Veterinary Ophthalmologists.
Publication Date: 2020-06-10 PubMed ID: 32519781DOI: 10.1111/vop.12794Google Scholar: Lookup
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Summary
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This research investigates the effects of cyclopentolate hydrochloride, a type of eye drops, on a horse’s pupils, tear production, and intraocular pressure; it found that this drug effectively dilates the pupils, doesn’t affect tear production or intraocular pressure, and could be safely used as a mydriatic/cycloplegic drug in horses.
Research Design and Methodology
In the study:
- Fourteen horses that were clients’ pets were used as subjects.
- The study had two phases. In each phase, the horses were treated with the cyclopentolate hydrochloride in one eye (the treated eye) whereas the other eye (the control eye) was treated with a simple saline solution.
- In the first phase, tear production (TP), intraocular pressure (IOP), and pupillometric readings (PR) were assessed at various intervals post-instillation from 1 to 196 hours. TP was tested using the Schirmer tear test I, IOP with rebound tonometry and PR by static pupillometry.
- In the second phase, the state of plateau mydriasis (severe dilation of the pupil) was evaluated by assessing PR hourly for the first 8 hours after instillation. The pupil area (PA), vertical pupil diameter (VPD), and horizontal pupil diameter (HPD) were measured and recorded.
- All pupillometry measurements were obtained in a room with fixed light intensity to control external factors impacting pupil size.
- Statistical analysis was performed to observe the effect on these parameters over time and to assess any differences between the treated and control eyes.
Results of the Study
- Results showed significant pupil dilation observed from 1 to 172 hours in the treated eyes for VPD, and from 8 to 24 hours for the PA. However, there was no significant difference observed in the HPD over any time.
- In the second phase, it was observed that PA and VPD reached plateau at approximately 3 hours after treatment, while HPD plateaued quicker, at the 2-hour mark.
- Importantly, no significant effects were observed on tear production and intraocular pressure in either the treated or control eyes at any time.
- Additionally, the pupillometric readings of the untreated eyes did not show any significant alterations.
Conclusions
- The results indicate the potential usage of cyclopentolate hydrochloride as an effective and safe option to induce pupil dilation (mydriasis) without affecting tear production or intraocular pressure in horses.
Cite This Article
APA
Ortillés Á, Sanmartí J, Ríos J, Armengou L, Peña MT, Leiva M.
(2020).
Effects of topical 1% cyclopentolate hydrochloride on quantitative pupillometry measurements, tear production and intraocular pressure in healthy horses.
Vet Ophthalmol, 23(4), 730-739.
https://doi.org/10.1111/vop.12794 Publication
Researcher Affiliations
- Fundació Hospital Clínic Veterinari, Campus Universitat Autònoma de Barcelona, Bellaterra, Spain.
- Fundació Hospital Clínic Veterinari, Campus Universitat Autònoma de Barcelona, Bellaterra, Spain.
- Laboratory of Biostatistics & Epidemiology, Universitat Autònoma de Barcelona, Bellaterra, Spain.
- Fundació Hospital Clínic Veterinari, Campus Universitat Autònoma de Barcelona, Bellaterra, Spain.
- Departament de Medicina i Cirurgia Animal, Facultat de Veterinaria, Universitat Autònoma de Barcelona, Bellaterra, Spain.
- Fundació Hospital Clínic Veterinari, Campus Universitat Autònoma de Barcelona, Bellaterra, Spain.
- Departament de Medicina i Cirurgia Animal, Facultat de Veterinaria, Universitat Autònoma de Barcelona, Bellaterra, Spain.
- Fundació Hospital Clínic Veterinari, Campus Universitat Autònoma de Barcelona, Bellaterra, Spain.
- Departament de Medicina i Cirurgia Animal, Facultat de Veterinaria, Universitat Autònoma de Barcelona, Bellaterra, Spain.
MeSH Terms
- Animals
- Cyclopentolate / administration & dosage
- Cyclopentolate / pharmacology
- Female
- Horses
- Intraocular Pressure / drug effects
- Male
- Mydriatics / administration & dosage
- Mydriatics / pharmacology
- Ophthalmic Solutions / administration & dosage
- Ophthalmic Solutions / pharmacology
- Reference Values
- Tears / drug effects
- Tonometry, Ocular / veterinary
References
This article includes 37 references
- Herring IP. Chapter 7: Clinical pharmacology and therapeutics. Part 4: Mydriatics/cycloplegics, anesthetics, and tear substitutes and stimulators.. Veterinary Ophthalmology 5th ed. Ames, IA: Wiley-Blackwell; 2013:423-434.
- Maggs DJ. Chapter 3: Ophthalmic medication and therapeutics.. Slatter’s Fundamentals of Veterinary Ophthalmology 6th ed. St. Louis, MO: Elsevier Saunders; 2018:51-88.
- Williams DL. Chapter 3: Common features of exotic animal ophthalmology.. Ophthalmology of Exotic Pets 1st ed. West Sussex, UK: Wiley-Blackwell; 2012:9-14.
- Gelatt KN, Gum GG, Mackay EO. Evaluation of mydriatics in horses.. Vet Comp Ophthalmol 1995;5:104-108.
- Margadant DL, Kirkby K, Andrew SE. Effect of topical tropicamide on tear production as measured by Schirmer’s tear test in normal dogs and cats.. Vet Ophthalmol 2003;6:315-320.
- Selk Ghaffari M, Javadzadeh R, Rajaei SM. Effects of two concentrations of topical tropicamide on the Schirmer tear test in clinically normal cats.. J Feline Med Surg 2016;18:965-969.
- Selk Ghaffari M, Sabzevari A, Radmehr B. Effect of topical 1% tropicamide on Schirmer tear test results in clinically normal horses.. Vet Ophthalmol 2009;12:369-371.
- Hollingsworth SR, Canton DD, Buyukmihci NC. Effect of topically administered atropine on tear production in dogs.. J Am Vet Med Assoc 1992;200:1481-1484.
- Arnett BD, Brightman AH, Musselman EE. Effect of atropine sulfate on tear production in the cat when used with ketamine hydrochloride and acetylpromazine maleate.. J Am Vet Med Assoc 1984;185:214-215.
- Costa D, Leiva M, Coyo N. Effect of topical 1% cyclopentolate hydrochloride on tear production, pupil size, and intraocular pressure in healthy Beagles.. Vet Ophthalmol 2016;19:449-453.
- Ansari Mood M, Rajaei SM, Faghihi H. Effect of topical 1% cyclopentolate hydrochloride on tear production, intraocular pressure, and pupil size in healthy Turkman horses.. J Equine Vet Sci 2019;75:25-29.
- Ribeiro AP, Crivelaro RM, Teixeira PPM. Effects of different mydriatics on intraocular pressure, pupil diameter, and ruminal and intestinal motility in healthy sheep.. Vet Ophthalmol 2014;17:397-402.
- Wallin-Hakanson N, Wallin-Hakanson B. The effects of topical tropicamide and systemic medetomidine, followed by atipamezole reversal, on pupil size and intraocular pressure in normal dogs.. Vet Ophthalmol 2001;4:3-6.
- Taylor NR, Zele AJ, Vingrys AJ. Variation in intraocular pressure following application of tropicamide in three different dog breeds.. Vet Ophthalmol 2007;10:8-11.
- Kahane N, Raskansky H, Bdolah-Abram T. The effects of topical parasympatholytic drugs on pupil diameter and intraocular pressure in healthy dogs treated with 0.005% latanoprost.. Vet Ophthalmol 2016;19:464-472.
- Kovalcuka L, Ilgazs A, Bandere D. Changes in intraocular pressure and horizontal pupil diameter during use of topical mydriatics in the canine eye.. Open Vet J 2017;7:16-22.
- Jugant S, Grillot AE, Lyarzhri F. Changes in pupil size and intraocular pressure after topical application of 0.5% tropicamide to the eyes of dogs sedated with butorphanol.. Am J Vet Res 2019;80:95-101.
- Stadtbaumer K, Frommlet F, Nell B. Effects of mydriatics on intraocular pressure and pupil size in the normal feline eye.. Vet Ophthalmol 2006;9:233-237.
- Knickelbein KE, Scherrer NM, Lassaline M. Corneal sensitivity and tear production in 108 horses with ocular disease.. Vet Ophthalmol 2018;21:76-81.
- Piccione G, Giannetto C, Fazio F. Daily rhythm of tear production in normal horse.. Vet Ophthalmol 2008;11:57-60.
- Kovalcuka L, Birgele E, Bandere D. Comparison of the effects of topical and systemic atropine sulfate on intraocular pressure and pupil diameter in the normal canine eye.. Vet Ophthalmol 2015;18:43-49.
- Stoppini R, Gilger BC. Chapter 1: Equine ocular examination basic techniques.. Equine Ophthalmology 3rd edn. Ames, IA: Wiley-Blackwell; 2017:1-39.
- Visser HE, Diehl KA, Whitley RD. Effect of auriculopalpebral nerve block on Schirmer tear test I values in normal horses.. Vet Ophthalmol 2017;20:568-570.
- Trbolova A, Ghaffari MS. Results of the Schirmer tear test performed with open and closed eyes in clinically normal horses.. Acta Vet Scand 2017;59:35.
- Beech J, Zappala RA, Smith G. Schirmer tear test results in normal horses and ponies: effect of age, season, environment, sex, time of day and placement of strips.. Vet Ophthalmol 2003;6:251-254.
- Dulaurent T, Goulle F, Dulaurent A. Effect of mydriasis induced by topical instillations of 0.5% tropicamide on the anterior segment in normotensive dogs using ultrasound biomicroscopy.. Vet Ophthalmol 2012;15:8-13.
- Mughannam AJ, Buyukmihci NC, Kass PH. Effect of topical atropine on intraocular pressure and pupil diameter in the normal horse eye.. Vet Ophthalmol 1999;2:213-215.
- Herring IP, Pickett JP, Champagne ES. Effect of topical 1% atropine sulfate on intraocular pressure in normal horses.. Vet Ophthalmol 2000;3:139-143.
- Michau TM. Equine glaucoma.. Vet Clin North Am Equine Pract 2017;33:519-540.
- Williams MM, Spiess BM, Pascoe PJ. Systemic effects of topical and subconjunctival ophthalmic atropine in the horse.. Vet Ophthalmol 2000;3:193-199.
- Von Zup M, Lassaline M, Kass PH. Effects of 0.2% brimonidine and 0.2% brimonidine-0.5% timolol on intraocular pressure and pupil size in normal equine eyes.. Equine Vet J 2017;49:810-814.
- Davis JL, Stewart T, Brazik E. The effect of topical administration of atropine sulfate on the normal equine pupil: influence of age, breed and gender.. Vet Ophthalmol 2003;6:329-332.
- Palmero J, Hollingsworth S, Kass P. Field use of N-butylscopolammonium bromide to facilitate thorough ophthalmic examination in horses.. Vet J 2016;211:104-105.
- Hacker DV, Buyukmihci NC, Franti CE. Effect of topical phenylephrine on the equine pupil.. Am J Vet Res 1987;48:320-322.
- Wehrman RF, Gemensky-Metzler AJ, Zibura AE. Objective evaluation of the systemic effects of topical application of 1% atropine sulfate ophthalmic solution in healthy horses.. J Am Vet Med Assoc 2017;251:1324-1330.
- McMullen RJ, Davidson MG, Gilger BC. The effect of 1% tropicamide-induced mydriasis and cycloplegia on spherical refraction of the adult horse.. Vet Ophthalmol 2014;17:120-125.
- Hahn CN, Mayhew IG. Studies on the experimental induction of ptosis in horses.. Vet J 2000;160:220-224.
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