title: Ocular perfusion pressure and color Doppler imaging of the external ophthalmic artery of rabbits treated with sildenafil citrate.
abstract: BACKGROUND
  It has been proposed that sildenafil citrate can increase ocular blood flow, and that this property can be used to treat ocular disorders that involve reflex vasoconstriction. This study therefore proposes to ascertain the vasodilator effect of the drug on retrobulbar circulation in healthy rabbits. For this matter rabbits treated with sildenafil citrate or saline solution had their intraocular pressure (IOP), mean arterial pressure (MAP), ocular perfusion pressure (OPP) and color Doppler imaging of the external ophthalmic artery measured prior to treatment and on days one (moment M1), seven (when M2), fourteen (moment M3), twenty-one (moment M4), and thirty (moment M5) of treatment.
  
  
  RESULTS
  The MAP and OPP values of treated group were lower than those of control group at all times, and the mean values differed statistically at moments M1 (S = 71.52 mmHg, C = 84.76 mmHg, p = 0.0356) and M5 (S = 71.38 mmHg, C = 85.52 mmHg, p = 0.0252). The IOP and color Doppler values of the external ophthalmic artery did not differ between tested groups.
  
  
  CONCLUSIONS
  The dose of 10 mg of sildenafil citrate administered to healthy rabbits causes systemic vasodilation and consequently lower values of MAP and OPP. However, it does not induce changes in IOP and retrobulbar hemodynamics identifiable by color Doppler assessment of the external ophthalmic artery.
authors.affiliation: Department of Veterinary Medicine, School of Veterinary Medicine and Animal Science, Veterinary Hospital, Federal University of Goiás, Campus Samambaia, Caixa Postal 131, Goiânia, Goiás State, CEP 74001-970, Brazil. hananinha@gmail.com.
authors.forename: Ana Paula Araujo
authors.initials: AP
authors.lastname: Costa
authors.affiliation: Department of Veterinary Medicine, School of Veterinary Medicine and Animal Science, Veterinary Hospital, Federal University of Goiás, Campus Samambaia, Caixa Postal 131, Goiânia, Goiás State, CEP 74001-970, Brazil.
authors.forename: Aline Maria Vasconcelos
authors.initials: AM
authors.lastname: Lima
authors.affiliation: Department of Veterinary Medicine, School of Veterinary Medicine and Animal Science, Veterinary Hospital, Federal University of Goiás, Campus Samambaia, Caixa Postal 131, Goiânia, Goiás State, CEP 74001-970, Brazil.
authors.forename: Luiz Henrique
authors.initials: LH
authors.lastname: da Silva
authors.affiliation: Department of Veterinary Medicine, School of Veterinary Medicine and Animal Science, Veterinary Hospital, Federal University of Goiás, Campus Samambaia, Caixa Postal 131, Goiânia, Goiás State, CEP 74001-970, Brazil.
authors.forename: Rosângela
authors.initials: R
authors.lastname: de Oliveira Alves Carvalho
authors.affiliation: Department of Veterinary Medicine, School of Veterinary Medicine and Animal Science, Federal University of Goiás, Jataí, GO, Brazil.
authors.forename: Andréia Vitor Couto
authors.initials: AV
authors.lastname: do Amaral
authors.affiliation: Department of Veterinary Medicine, School of Veterinary Medicine and Animal Science, Veterinary Hospital, Federal University of Goiás, Campus Samambaia, Caixa Postal 131, Goiânia, Goiás State, CEP 74001-970, Brazil.
authors.forename: Naida Cristina
authors.initials: NC
authors.lastname: Borges
mesh_terms: D000818:Animals; D001783:Blood Flow Velocity / Q000187:drug effects; D007429:Intraocular Pressure / Q000187:drug effects*; D009880:Ophthalmic Artery / Q000033:anatomy & histology / Q000187:drug effects* / Q000502:physiology; D011817:Rabbits; D011897:Random Allocation; D000068677:Sildenafil Citrate / Q000494:pharmacology*; D018615:Ultrasonography, Doppler, Color; D014655:Vascular Resistance / Q000187:drug effects; D014665:Vasodilator Agents / Q000494:pharmacology*
chemical_list: D014665:Vasodilator Agents; D000068677:Sildenafil Citrate
keywords: Color Doppler imaging; Eye circulation; Intraocular pressure; Mean arterial pressure; Phosphodiesterase type 5 inhibitor; Rabbit