title: Steroid-induced ocular hypertension in normal sheep.
abstract: OBJECTIVE
  To determine whether the ovine eye develops elevation of intraocular pressure (IOP) in response to corticosteroid applied topically.
  
  
  METHODS
  IOP was monitored by Perkins applanation tonometry in a group of 18 sheep receiving topically administered 0.5% prednisolone acetate in one eye (experimental), three times daily, for a period of 3 or four 4 weeks after the establishment of baseline IOP values. Perkins readings were converted to actual mm Hg using a calibration curve derived from in vivo manometric measurements. IOP was monitored for an additional 1 to 3 weeks after discontinuation of corticosteroid treatment.
  
  
  RESULTS
  Baseline IOP in normal sheep was 10.6+/-1.4 mm Hg (mean +/- SD; n=36 eyes). The IOP of the experimental eyes began to increase after 1 week of prednisolone treatment in all sheep and reached a peak 1 week later (27.5 mm Hg experimental vs. 11.7 mm Hg fellow, control eye; P<0.001). After the discontinuation of corticosteroid instillation, the IOP of the treated eyes declined to the baseline values over the course of 1 to 3 weeks.
  
  
  CONCLUSIONS
  Ovine eyes exhibit a robust steroid-induced ocular hypertensive response, with 100% occurrence in this trial. The mechanisms of steroid-induced glaucoma may be related to those involved in primary open-angle glaucoma and could provide insight into primary open-angle and clues to its treatment.
authors.affiliation: Departamento de Farmacología, Facultad de Medicina, Universidad Nacional Del Nordeste, Corrientes, Argentina.
authors.forename: Rosana
authors.initials: R
authors.lastname: Gerometta
authors.forename: Steven M
authors.initials: SM
authors.lastname: Podos
authors.forename: John
authors.initials: J
authors.lastname: Danias
authors.forename: Oscar A
authors.initials: OA
authors.lastname: Candia
mesh_terms: D000287:Administration, Topical; D000818:Animals; D004195:Disease Models, Animal; D005938:Glucocorticoids / Q000633:toxicity*; D007429:Intraocular Pressure / Q000187:drug effects*; D009798:Ocular Hypertension / Q000139:chemically induced*; D011239:Prednisolone / Q000031:analogs & derivatives* / Q000633:toxicity; D012756:Sheep; D014065:Tonometry, Ocular
chemical_list: D005938:Glucocorticoids; C009935:prednisolone acetate; D011239:Prednisolone