This study will document the clinical and genetic features of glaucoma and related diseases, including normal tension glaucoma (NTG). Researchers would like to define genetic influences and eventually isolate the genes causing those diseases.

Glaucoma is an important cause of vision loss in the United States and worldwide. The disease is marked by a wearing down of the retina and optic nerve, often associated with increased pressure in the eye. It is often an inherited trait. This study will involve between 250 and 2,000 patients over a 5-year period. It will examine the natural history of the genotype, or genetic makeup, of a person and the phenotype, that is, visible situations produced by the interaction of the genotype and one's environment.

Patients 4 and older who have glaucoma or related diseases or whose family members have those diseases may be eligible for this study. They will complete a medical history for the doctors to verify the diagnosis, inquire about medical problems and surgical operations, and gather data about vision problems in a patient's family (by drawing a family tree). The complete eye examination may take several hours. Eye drops will be used to dilate, or enlarge, the pupils of patients' eyes, and the pupils will stay dilated for 4 to 6 hours. There may be some temporary glare in brightly lit areas, which can be reduced by wearing of sunglasses. Patients may experience some blurring of vision. There may be a localized allergic reaction to the medication used or an increase of pressure inside the eye. If that occurs, medication to control the reaction will be given. In addition, photographs of the retina and perhaps even the lens will be taken. For that procedure, eye drops will dilate the pupils of the eyes. The light that is involved with the specialized photography may cause some mild discomfort. Patients will undergo eye tests regarding color vision, field of vision, and ability to see the dark. Also, there will be a measurement of pressure in the eye and thickness of the cornea.

To study patients' DNA, the researchers will obtain a blood sample of about 4 teaspoons from patients 10 years or older. A smaller amount of about 1 teaspoon for each 5 lb. of body weight will be collected from younger patients. Those DNA samples will be used only for research in the genetic disorder in a patient's family. No other testing or research will be conducted on the blood samples without patients' separate permission. Also, the DNA will be stored by codes that the researchers define and contained in a secured building.

In this study, researchers will not provide information about a patient's health to patient family members or to other people. They will not discuss information such as adoption or biological fatherhood unless it has medical implications for the patient or the patient's family members.

If information obtained from this study may be important to patients' health, they will be informed when it is available. There are no plans to give patients the results of any medical tests, evaluations, or other research data. Further research may be needed before such results become meaningful.