title: Effect of topical 1% cyclopentolate hydrochloride on tear production, pupil size, and intraocular pressure in healthy Beagles.
abstract: OBJECTIVE
  The objective of the study was to evaluate the effect of topical 1% cyclopentolate hydrochloride (CH) on tear production (TP), pupil size (PS), and intraocular pressure (IOP) in dogs.
  
  
  METHODS
  Fifteen healthy beagle dogs from the UAB research-teaching colony.
  
  
  METHODS
  Dogs without ocular diseases were included. Each animal received one drop of 1% CH ophthalmic solution in a randomly selected eye. TP, PS, and IOP were evaluated by means of STT-1, static pupillometry, and rebound tonometry, respectively. Evaluations were performed before drug instillation and at 0.5, 1, 2, 4, 8, 12, 24, 30, 36, 48, 54, 60, 72, 84, and 96 h postinstillation. Examinations took place in a room with fixed light intensity (40-55 lux). Statistical analysis was performed by means of generalized estimating equations for the effect on STT-1, pupil size, and IOP over time.
  
  
  RESULTS
  After unilateral application of 1% CH, significant pupillary dilation started at 30 min, reached its maximum at 12 h, and returned to pre-instillation size after 72 h. No significant effects were found on TP or IOP, at any time. No effects were observed in the untreated eye on any of the parameters evaluated.
  
  
  CONCLUSIONS
  Cyclopentolate hydrochloride could be considered a therapeutic alternative when use of a cycloplegic drug is needed and effects on tear production and IOP are unwanted.
authors.affiliation: Departament de Medicina i Cirurgia Animal, Facultat de Veterinaria Edifici V, Universitat Autònoma de Barcelona, Bellaterra, 08193, Spain.
authors.forename: Daniel
authors.initials: D
authors.lastname: Costa
authors.affiliation: Departament de Medicina i Cirurgia Animal, Facultat de Veterinaria Edifici V, Universitat Autònoma de Barcelona, Bellaterra, 08193, Spain. marta.leiva@uab.cat.|Fundació Hospital Clínic Veterinari, Campus Universitat Autònoma de Barcelona, Bellaterra, 08193, Spain. marta.leiva@uab.cat.
authors.forename: Marta
authors.initials: M
authors.lastname: Leiva
authors.affiliation: Departament de Medicina i Cirurgia Animal, Facultat de Veterinaria Edifici V, Universitat Autònoma de Barcelona, Bellaterra, 08193, Spain.
authors.forename: Natàlia
authors.initials: N
authors.lastname: Coyo
authors.affiliation: Fundació Hospital Clínic Veterinari, Campus Universitat Autònoma de Barcelona, Bellaterra, 08193, Spain.
authors.forename: Fernando
authors.initials: F
authors.lastname: Laguna
authors.affiliation: Laboratory of Biostatistics & Epidemiology, Universitat Autònoma de Barcelona, Bellaterra, 08193, Spain.
authors.forename: Jose
authors.initials: J
authors.lastname: Ríos
authors.affiliation: Departament de Medicina i Cirurgia Animal, Facultat de Veterinaria Edifici V, Universitat Autònoma de Barcelona, Bellaterra, 08193, Spain.|Fundació Hospital Clínic Veterinari, Campus Universitat Autònoma de Barcelona, Bellaterra, 08193, Spain.
authors.forename: Maria Teresa
authors.initials: MT
authors.lastname: Peña Gimenez
mesh_terms: D000818:Animals; D003519:Cyclopentolate / Q000008:administration & dosage / Q000494:pharmacology*; D004285:Dogs; D007429:Intraocular Pressure / Q000187:drug effects*; D009184:Mydriatics / Q000008:administration & dosage / Q000494:pharmacology*; D011680:Pupil / Q000187:drug effects* / Q000502:physiology; D011897:Random Allocation; D013666:Tears / Q000378:metabolism*; D014065:Tonometry, Ocular
chemical_list: D009184:Mydriatics; D003519:Cyclopentolate
keywords: Schirmer tear test; canine; cycloplegic drug; eye; intraocular pressure; pupil