Eye - Macular Edema (Diabetes) Confused?

Hi Doctor, My mother has diabetes since the past decade and was recently (5 months ago) diagnosed with Macular Edema. We had carried out OCT in February 2018 and got the recommendation to apply the Lucentis Injection. Since then, I have monitored her sugar levels and ensured that it is between 90 - 160 (always). We gave her the injection on April end and after 1 month cool off, carried out the OCT once again. The results show that the swelling in the eye has increased (as interpreted by doctor). Before January 2018, her sugar level used to hover around 180 to 280. What's strange and worrysome is that even after taking the injection and intensive sugar control, the swelling has increased. Can you please help me with this situation and help me understand that how did this happen and what should be the next steps as I am confused? I have attached the OCT of February( before injection, black background) and OCT of June (After injection, pink background). Thanks