In this study, patients were divided into 3 group with 35 cases including: 1.oxygen 2.enalapril 3.control.

In the beginning of the study, best corrected visual acuity (BCVA), uncorrected visual acuity (UCVA), and optical coherence tomography (OCT) were measured. Patients in the oxygen group were given oxygen 10 lit/min 1 hour twice a day at the first month, once a day at the second month and every other day at the third month. In the enalapril group, patients were given enalapril 5 mg every night and placebo was given for the patients in third group. At the end of first month the patients' vision was checked again and at the the end of the third month the first physical examinations were performed. In the first group, arterial blood gas (ABG) was taken before and after oxygen therapy as well.

Inclusion Criteria:

• Patients diagnosed with diabetic macular ischemia

Exclusion Criteria:

• HTN > 1140/90 or HTN controlled by ACE inhibitors
• FBS > 200
• Severe anemia, COPD, cataract, HRPDR and diffuse macular edema