If the second intervention fails, both groups receive trabeculectomy. The investigators compare vision after the two types of surgery, complications, and the need for additional treatments. Patient recruitment is complete. If this fails to lower pressure inside the eye, surgery is performed. The U-M Kellogg Eye Center is coordinating the entire study, which is taking place at 14 other clinical sites around the country.
Patient recruitment is complete.
Patients with ocular hypertension are either observed at their current level of intraocular pressure or are given eye drops used to lower the pressure to see if this prevents or delays glaucoma damage. Recruitment is complete. Longitudial followup of patients with ischemic optic neuropathy to determine visual outcome systemic outcome and rate of involvement of other eye.