In this study, which will be performed as a randomized clinical trial, all patients with macular edema with central involvement (central macular thickness greater than 300 μm) and corrected vision less than or equal to 20/40 and better than 20/400 were included in the study. After a thorough eye examination, people are randomly divided into two groups. The first group was treated with intravitreal injection of Bevacizumab in three injections one month apart with receiving oral Acetazolamide tablets of 250 mg twice a day, and the second group was treated with intravitreal injection of Bevacizumab for three Loads are spaced one month apart. Ophthalmologic examinations and corrected visual acuity, as well as macular thickness examination, are repeated with Spectral-domain Optical coherence tomography (SD-OCT) at the beginning of treatment and at the end of the first, second, and third months. At the end of the study, the rate of changes in visual acuity and macular thickness in the eyes in the two groups will be compared and will be statistically analyzed.

Inclusion Criteria:

• 20 / 400≤ Best Corrected Visual Acuity ≤20 / 40
• Central macular thickness <300 μm
• The onset of the disease is less than three years
• No other eye diseases that affect the evaluation and process of this study.

Exclusion Criteria:

• It is not possible to provide informed consent.
• Patients who are prohibited from taking oral acetazolamide (renal failure, hepatic failure, history of allergies)
• Other eye diseases that affect the evaluation and process of this study. Including diabetes retinopathy
• History of retinal laser photocoagulation