Optic nerve dynein motor protein distribution changes with intraocular pressure elevation in a rat model of glaucoma.

Acute intraocular pressure (IOP) elevation causes accumulation of retrogradely-transported brain derived neurotrophic factor and its receptor at the optic nerve head (ONH) in rats and monkeys. Obstruction of axonal transport may therefore be involved in glaucoma pathogenesis, but it is unknown if obstruction is specific to certain transported factors or represents a generalized failure of retrograde axonal transport. The dynein motor complex mediates retrograde axonal transport in retinal ganglion cells (RGC).

The transcription factor c-jun is activated in retinal ganglion cells in experimental rat glaucoma.

This study investigates the role of the MAP kinase pathway including c-jun, ATF-2 and JNK in glaucomatous eyes of rats and in optic nerve transection. Glaucoma was induced in one eye of 51 adult Wistar rats by laser treatment to the trabecular meshwork. Eighteen further rats underwent unilateral optic nerve transection.

Gene therapy with brain-derived neurotrophic factor as a protection: retinal ganglion cells in a rat glaucoma model.

Purpose: To develop a modified adenoassociated viral (AAV) vector capable of efficient transfection of retinal ganglion cells (RGCs) and to test the hypothesis that use of this vector to express brain-derived neurotrophic factor (BDNF) could be protective in experimental glaucoma.

Methods: Ninety-three rats received one unilateral, intravitreal injection of either normal saline (n = 30), AAV-BDNF-woodchuck hepatitis posttranscriptional regulatory element (WPRE; n = 30), or AAV-green fluorescent protein (GFP)-WPRE (n = 33). Two weeks later, experimental glaucoma was induced in the injected eye by laser application to the trabecular meshwork.

A model to study differences between primary and secondary degeneration of retinal ganglion cells in rats by partial optic nerve transection.

Purpose: To use a rat model of optic nerve injury to differentiate primary and secondary retinal ganglion cell (RGC) injury.

Methods: Under general anesthesia, a modified diamond knife was used to transect the superior one third of the orbital optic nerve in albino Wistar rats. The number of surviving RGC was quantified by counting both the number of cells retrogradely filled with fluorescent gold dye injected into the superior colliculus 1 week before nerve injury and the number of axons in optic nerve cross sections.

Gene delivery to the eye using adeno-associated viral vectors.

Adeno-associated virus (AAV) vectors provide a useful way to deliver genes to the eye. They have a number of important properties which make them suitable for this purpose, not least their lack of significant pathogenicity and the potential for long-term transfection of retinal cells. The optimal methods for AAV-mediated gene delivery are determined by the location and characteristics of the target cell type.

Measurement of amino acid levels in the vitreous humor of rats after chronic intraocular pressure elevation or optic nerve transection.

Purpose: To investigate whether the levels of free amino acids and protein in the vitreous of rat eyes are altered with chronic intraocular pressure (IOP) elevation or after optic nerve transection.

Materials And Methods: The concentrations of 20 amino acids in the vitreous humor were measured by high-performance liquid chromatography in both eyes of 41 rats with unilateral IOP elevation induced by translimbal photocoagulation. Eyes were studied 1 day and 1, 2, 4, and 9 weeks after initial IOP elevation.

Retinal glutamate transporter changes in experimental glaucoma and after optic nerve transection in the rat.

Purpose: High levels of glutamate can be toxic to retinal ganglion cells. Effective buffering of extracellular glutamate by retinal glutamate transporters is therefore important. This study was conducted to investigate whether glutamate transporter changes occur with two models of optic nerve injury in the rat.

Translimbal laser photocoagulation to the trabecular meshwork as a model of glaucoma in rats.

Purpose: To develop and characterize a model of pressure-induced optic neuropathy in rats.

Methods: Experimental glaucoma was induced unilaterally in 174 Wistar rats, using a diode laser with wavelength of 532 nm aimed at the trabecular meshwork and episcleral veins (combination treatment group) or only at the trabecular meshwork (trabecular group) through the external limbus. Intraocular pressure (IOP) was measured by a tonometer in rats under ketamine-xylazine anesthesia.