Abstract
Purpose:
To examine polysialic acid neural cell adhesion molecule (PSA-NCAM) expression after microbead-induced ocular hypertension in retinas and optic nerves of mice that lack brain derived neurotrophic factor (BDNF+/-) and their wild type littermates (WT).
Methods:
Intraocular pressure (IOP) was elevated unilaterally by injection of polystyrene microbeads into the anterior chamber to occlude aqueous outflow. Retinas and optic nerves were harvested 1, 3 and 6- weeks after the treatment. Effects of the treatment on retinal ganglion cell layer (RGCL) cells and axons of the optic nerve were determined by stereological methods. The immunoreactive expression of PSA-NCAM in the eye was detected by immunofluorescence and electron microscopy.
Results:
Mean IOP in the glaucoma-treated eyes was 10.8±1.2 mmHg in WT mice and 11.0±0.6 mmHg in BDNF+/- mice. Contralateral control eyes had a steady IOP level that was maintained at an average value of 7.7±0.2 mmHg. There was no statistically significant RGCL cells loss or axon damage detected in the glaucomatous eyes. PSA-NCAM expression was increased in astrocytes in optic nerves and retinas with experimental glaucoma. The lack of BDNF did not influence on the expression levels of PSA-NCAM as compared to WT littermates.
Conclusions:
Our data indicate that partial loss of BDNF does not induce higher glaucomatous damage in the retina and optic nerve. Retinal and optic nerve glia respond to increased IOP by overexpressing PSA-NCAM. However, we did not observe PSA-NCAM expression in RGCL neurons.
Keywords: 568 intraocular pressure •
429 astrocyte