Following randomization, participating community ophthalmologists affiliated with the study have been allowed to manage the medical and surgical care of study patients. However, all patients are seen at the Clinical Centers for standardized followup examinations at 3 and 6 months after treatment and every 6 months thereafter; in addition, patients randomized to the surgical arm will receive, at a minimum, postsurgical followup at 1 day, 1 week, and 1 month. At the Clinical Center visits, examination of the eye(s) includes evaluation of visual acuity, visual field, and intraocular pressure. The results of these tests determine whether treatment should be changed. In addition, before and at regular intervals after treatment, patients are being interviewed by telephone to assess their health-related quality of life. A questionnaire that includes the Sickness Impact Profile, Visual Activities Questionnaire, and other components is being used.