Background: Diabetic retinopathy is a common microvascular complication of type 2 diabetics. Magnesium (Mg), a key intracellular electrolyte, which plays a pivotal role in glucose metabolism, insulin function, and vascular health. Its deficiency might be linked with metabolic disorders and microvascular complications including DR.

Aim of the Study: To assess serum Mg level in type 2 diabetes mellitus with and without diabetic retinopathy and to investigate its correlation with diabetic retinopathy.

Patients and Methods: This is a cross-sectional comparative study conducted at the Ophthalmology Center, Ghazi Al-Hariri Hospital for Surgical Specialties, Baghdad, Iraq, from March to August 2024. A total of 193 patients aged 40 years with type 2 diabetes mellitus were included, comprising 93 with diabetic retinopathy and 100 without. Serum magnesium and HbA1c levels were measured.

Results: Low serum magnesium was significantly more common in patients with diabetic retinopathy (29%) compared to those low Mg levels and both non-proliferative diabetic retinopathy (p = 0.012) and proliferative diabetic retinopathy (p = 0.029). However, no significant association was found between HbA1c or diabetes duration with Mg levels.

Conclusion: Serum magnesium deficiency is significantly associated with diabetic retinopathy in type 2 diabetics. However, magnesium levels were not significantly different between non-proliferative and proliferative cases.