Could retinal bleeding be due to hba1c?

Yes. High hba1c (generally greater than 7.0) is an indicator of poorly controlled diabetes mellitus. When the blood sugar is elevated for an extended period of time, particularly if coupled with high blood pressure, it damages blood vessels throughout the body. In the eye this blood vessel damage can lead to bleeding in the retina or the vitreous cavity.
Not really. Hemoglobin a1c (hba1c) is a measure of how well your blood sugar has been controlled over the past 3 months. The higher the hba1c, the higher your blood sugars have been averaging, and the worse your diabetes is doing. Bad/uncontrolled diabetes can lead to retinal bleeding.