Repeat sample intraocular pressure variance in induced and naturally ocular hypertensive monkeys.

Purpose: To compare repeat-sample means variance of laser induced ocular hypertension (OH) in rhesus monkeys with the repeat-sample mean variance of natural OH in age-range matched monkeys of similar and dissimilar pedigrees.

Materials & Methods: Multiple monocular, retrospective, intraocular pressure (IOP) measures were recorded repeatedly during a short sampling interval (SSI, 1-5 months) and a long sampling interval (LSI, 6-36 months). There were 5-13 eyes in each SSI and LSI subgroup.

Functional damage to inner and outer retinal cells in experimental glaucoma.

Purpose: To investigate the cellular sources underlying the functional damage observed by multifocal electroretinography (mfERG) responses of glaucomatous eyes of monkeys.

Methods: First- and second-order (K1 and K2, respectively) mfERG responses of three normal and three experimentally induced glaucomatous eyes of cynomolgus monkeys were measured at two different levels of luminance. Retinal contributors to the responses were isolated by intravitreal injections of pharmacological agents that suppress specific retinal cells.

Passive attenuation of cortical pattern evoked potentials with increasing body weight in young male rhesus macaques.

The purpose of our study was to determine changes in amplitudes and implicit times of retinal and cortical pattern evoked potentials with increasing body weight in young, growing rhesus macaques (Macaca mulatta). Retinal and cortical pattern evoked potentials were recorded from 29 male rhesus macaques between 3 and 7 years of age. Thirteen animals were reexamined after 11 months.

Guidelines for clinical electroretinography in the dog.

These procedures described for the dog ERG were approved at the 1st European Conference on Veterinary Visual Electrophysiology in Vienna, Austria, May 30, 2000. Dr. Narfström was Chair of the Committee for a Harmonized ERG Protocol, appointed by the European College of Veterinary Ophthalmology (ECVO), and Dr.

The effect of contrast and luminance on mfERG responses in a monkey model of glaucoma.

Purpose: To evaluate the effect of contrast and luminance attenuation on the multifocal electroretinogram (mfERG) responses of normal and glaucomatous eyes of cynomolgus monkeys.

Methods: Nine adult male cynomolgus monkeys with unilateral experimentally induced glaucoma were used. Hypertension-induced damage was confirmed by tomography of the optic disc.

Partial antagonism of endothelin 1-induced vasoconstriction in the human choroid by topical unoprostone isopropyl.

Background: There is increasing evidence that reduced ocular blood flow plays a role in the pathogenesis of glaucoma. In patients with normal-tension glaucoma, ocular blood flow abnormalities may be associated with dysfunction of the endothelin 1 (ET-1) regulation system.

Objective: To test the hypothesis that unoprostone, a topical docosanoid, may affect ET-1--induced vasoconstriction in the human choroid.

Studies on receptor binding and signal transduction pathways of unoprostone isopropyl.

We examined the binding characteristics of unoprostone isopropyl and its metabolite, M1 (M1), in bovine corpus luteum membranes, mobilization of intracellular calcium in human ciliary muscle cells and cyclic AMP generation in rabbit iris-ciliary body. The ligand binding assay of 3H-unoprostone isopropyl and M1 did not demonstrate any specific binding of these compounds in the bovine corpus luteum membranes. However, there was a high specific binding of prostaglandin F2alpha.

Mechanisms of action of unoprostone on trabecular meshwork contractility.

Purpose: This study was performed to clarify the possible mechanism behind the ocular hypotensive effect of unoprostone isopropyl (Rescula; Novartis Ophthalmics AG, Basel, Switzerland), a new docosanoid that has been shown to reduce intraocular pressure (IOP) in patients with ocular hypertension or primary open-angle glaucoma. To gain insight into the possible mode of action, the effects of unoprostone on ciliary muscle (CM) and trabecular meshwork (TM) contractility, intracellular calcium levels, and membrane channels were investigated.

Methods: The effects of unoprostone (M1 metabolite = free acid, 10(-5) M) and endothelin (ET)-1 (10(-9) M) on bovine TM (BTM) and ciliary muscle (CM) strips were investigated, by using a custom-made force-length transducer system.

Comparison of the vasoactive effects of the docosanoid unoprostone and selected prostanoids on isolated perfused retinal arterioles.

Purpose: To compare the vasoactive properties of the docosanoid unoprostone, its free acid, and different members of the prostanoid family on isolated perfused pig retinal arterioles to assess their potential to modulate retinal blood flow.

Methods: Segments of porcine retinal arterioles were dissected, cannulated, and perfused, and their diameter monitored during either intraluminal or extraluminal application of increasing doses (10(-10)-10(-4) M) of either the docosanoid unoprostone isopropyl and its free acid or of selected prostanoids: prostaglandin (PG) F(2alpha) and thromboxane A(2) analogue (U46619). Studies were performed on arterioles in their uncontracted state, and also during precontraction with endothelin-1 (10(-9) M).

The effect of 0.12% unoprostone isopropyl (rescula) on intraocular pressure in normotensive dogs.

Rescula (0.12% unoprostone isopropyl) is the first docosanoid compound approved for treatment of glaucoma in humans. It is commercially available in Japan, and is undergoing clinical testing elsewhere.

Ocular drug delivery in veterinary medicine.

This paper provides a comprehensive overview of the various approaches currently used in the development of ocular drug delivery systems for the treatment of ocular diseases in animals. It is obvious from the literature that most of the products that are currently available are derived from human medicine without consideration given to the differences which exist between the anatomy and physiology of the eye of various animal species which ultimately affect product design and performance. As a result, many of the products for animal use seem in many circumstances inappropriate for animal care.

Ocular blood flow in experimental glaucoma: a study in cynomolgus monkeys.

Experimental glaucoma was induced in 1 eye of 6 cynomolgus monkeys by laser treatment of the trabecular meshwork. In 5 of the 6 monkeys the increased intraocular pressure (IOP) caused marked glaucomatous damage in the experimental eye. Ocular blood flow was determined with labeled microspheres 4 years after the laser treatment.

Continuous intraocular pressure measurement by telemetry in alpha-chymotrypsin-induced glaucoma model in the rabbit: effects of timolol, dorzolamide, and epinephrine.

The aim of this study was to set-up and validate the use of a radio-telemetry system in order to record IOP in chronic ocular hypertensive animals. The transmitter of a miniaturized radio-telemetry system was implanted in rabbits, and its catheter was tunnelled subcutaneously to the superior conjunctival sac and inserted into the midvitreous. Implantation was performed in chronic ocular hypertensive rabbits induced by an injection of alpha-chymotrypsin into the posterior chamber of the eye.

Measurement of intraocular pressure by telemetry in conscious, unrestrained rabbits.

Purpose: The aim of this study was to develop a system for the continuous recording of the intraocular pressure (IOP) in rabbits maintained in their normal environment. A telemetric system originally designed for the measurement of cardiovascular parameters in unrestrained, conscious laboratory animals was adapted for this purpose.

Methods: Experiments were performed in adult albino female rabbits.