This study aimed to compare intravitreous conbercept alone with conbercept plus intravitreous triamcinolone acetonide in DME eyes which showed limited response to anti-VEGF treatment after one injection.

Some eyes with diabetic macular edema (DME) were not sensitive to anti-vascular endothelial growth factor (anti-VEGF) therapy and required continuous injections. Delayed control of macular edema might cause irreversible function loss. To predict the response to anti-VEGF treatment according to the CST change after one injection was proved reasonable recently. Adding intravitreous corticosteroids to the treatment regimen at early time might result in better outcomes than anti-VEGF therapy alone. Patients with diagnosis of refractory diabetic macular edema, confirmed by fluorangiography and optical coherence tomography (OCT), with limited response to one intravitreal anti-VEGF injection will be enrolled in the study. The enrolled patients will be randomized for the addition or not of the triamcinolone to intravitreal therapy.

Inclusion Criteria:

• Type II diabetes
• Vison decrease was mainly caused by diabetic macular edema (DME)
• BCVA of 20/800 to 20/40 (decimal)
• Central subfield retinal thickness (CST) ≥ 300μm by optical coherence tomography (OCT) in the study eye
• Pan-retinal photocoagulation finished at least 3 months ago, or no pan-retinal photocoagulation is expected in the next 6 months
• Within the last 3 months, one intravitreous injection of anti-VEGF agent was performed, the CST reduction one month after injection was ≤ 20%.

Exclusion Criteria:

• Non-DME related macular edema, or edema control would not benefit the vision (for example, macular atrophy)
• Exist of other reasons of macular edema, retinal vein occlusion, uveitis, iris rubeosis, high myopia
• Ocular media opacity of insufficient quality to obtain OCT images and fundus images in the study eye
• Intraocular or periorbital injection of steroids within the last 3 months
• Macular grid photocoagulation within the last 4 months
• History of vitrectomy
• History of scleral buckle within the last 4 months, or intraocular surgery is expected in the next 6 months
• Any sign of ocular infection, including conjunctivitis, hordeolum, dacryocystitis
• Myocardial infarction, heart failure, stroke, or transient ischemic attack within one month
• Pregnant or breastfeeding women
• Uncontrolled hypertension, or blood pressure >180/110
• Patients with uncontrolled hyperglycemia, or Hemoglobin A1C (HbA1c) ≥10.0%, or under hemodialysis , or started insulin usage within the last 4 months, or expected to start insulin use for hyperglycemia control in the next 4 months
• Those cannot follow visits on time