Laser vs Bevacizumab Injection Alone in Treatment of Diabetic Macular Edema

Currently, diabetic macular edema is treated is through injection of a medications such as off-label bevacizumab, which decreases the swelling in the retina. These injections are sometimes required monthly until the condition is controlled. Recently, there have been some new FDA approved treatments using laser that decrease the swelling. These approximately ten minute treatments do not require injections and don't cause permanent damage to the eye, and they may decrease the number of injections one needs to get to treat diabetic macular edema (DME).

The purpose of this randomized clinical trial is to determine whether subvisible laser in combination with intravitreal bevacizumab is non-inferior compared to current standard of care (intravitreal bevacizumab alone) in achieving favorable outcomes for visual acuity, mean macular thickness, and patient quality of life, and has fewer needed intravitreal bevacizumab injections throughout the course of the 12 month study period.

The patient is randomized into one of two study groups described below.

* Group 1: Intravitreal bevacizumab (IVB) will be administered at the first 3 monthly visits and subvisible laser treatment will be administered at the first visit. The the patient will undergo monthly visits, as he/she would with standard of care treatment, allowing for retreatment with monthly IVB and laser treatment every 3 months if defined retreatment criteria are met, as determined by a physician.
* Group 2: Intravitreal bevacizumab (IVB) will be administered at the first 3 monthly visits. The patient will then undergo monthly exams, as he or she would with standard of care treatment, allowing for retreatment with monthly IVB if defined retreatment criteria are met, as determined by a physician. The patient may also undergo sham laser treatment (he/she will be placed in front of laser but no laser will be activated) so that the patient isn't made aware of which treatment group he/she is a part of.

Other data that will be collected throughout the study at monthly examinations:

* Monthly Snellen Visual acuity test
* Monthly spectral-domain optical coherence tomography (SD-OCT) imaging using standard clinic protocol monthly
* Standard clinic diabetic montage Fundus photos at months 0,6,12
* Fluorescein angiography at months 0, 6, 12

The subjects' visit schedules will be the same as for routine standard of care for the IVB injection procedure. There are no additional appointments for this study.

All study procedures will be done at San Francisco General Hospital

Eligibility Criteria:
Inclusion Criteria:

* Inclusion criteria include adults ≥ 18 years with type 1 or 2 diabetes mellitus with DME secondary to diabetes mellitus involving the center of the macula in the study eye and with a decrease in vision is determined to be primarily the result of DME in the study eye. The study eye must have a BCVA ETDRS letter score of 50 to 24 (20/30 to 20/320) in the study eye. The patient should be on a stable medical diabetic regimen that is not expected to change.

Exclusion Criteria:

* Patients are excluded if they have had laser photocoagulation (panretinal or macular) in the study eye within 90 days of Day 1, more than two previous macular laser treatments in the study eye, previous use of intraocular or periocular corticosteroids in the study eye within 90 days of Day 1, previous treatment with antiangiogenic drugs in either eye (pegaptanib sodium, bevacizumab, ranibizumab, or aflibercept) within 45 days of Day 1, active proliferative diabetic retinopathy (PDR) in the study eye, with the exception of inactive, regressed PDR, uncontrolled diabetes mellitus, as defined by HbA1c \> 12%, or a patient who is functionally monocular, as defined by the clinician or vision worse than 20/400 in the fellow eye even if that eye is otherwise eligible for the study.