This application describes a five year longitudinal study of structural change in primary open angle glaucoma. This study will evaluate whether clinical evaluation with confocal scanning laser imaging an improve the detection of glaucomatous optic nerve damage and change. Specific Aims: 1. To evaluate and compare photographic and confocal scanning laser imaging techniques to detect optic and retinal nerve fiber layer damage and change. 2. To determine the quantitative temporal relationships between recognizable optic nerve damage and measurable visual field loss and how these relationships differ among patients. 3. To quantify age-related changes in the optic nerve in normal healthy eyes. Methods: This study will include 300 subjects aged 40 and older; 100 patients with primary open angle glaucoma, and 100 White and 100 African- American normal controls. Each subject will have a complete ophthalmologic and visual field examination annually. Images of the optic nerve will be obtained using photographic techniques (optic disc and retinal nerve fiber layer photography), confocal laser scanning ophthalmoscopy to determine optic disc and perpipapillary topography, and confocal scanning laser polarimetry to determine nerve fiber layer thickness. These data will be evaluated qualitatively and quantitatively for evidence o glaucomatous damage and change. This study will evaluate whether these advances in fundus imaging technology can improve the precision with which we can differentiate between normal and glaucoma eyes, and can detect and monitor glaucomatous optic neuropathy.