Assessing of the relationship between renal function tests and retinopathy stage in patients with type II diabetes

Retinopathy and nephropathy are long-term diabetes complications which are associated together. Renal dysfunction is a risk factor for progression and deterioration of diabetic retinopathy. Diabetes causes damage to the small blood vessels in the retina and kidney which eventually resulted in diabetic nephropathy, renal failure and blindness. Due to the high cost for treating of these complications it is better to prevent them.

We aimed to assess the patients' kidney function and retinal status in a group of diabetic patients to find probable association between nephropathy and retinopathy hence can prevent from serious renal complications.

In this cross-sectional study 253 patients with type 2 diabetes referring to ophthalmology clinics were evaluated. Eye examination was conducted by an ophthalmologist (vitreoretinal subspecialist) and disease stage was determined, then serum blood urea nitrogen (BUN) and creatinine tests and 24-hour urine collection for microalbuminuria were measured.

Mean of BUN and microalbuminuria had significant difference in three groups including proliferative retinopathy, non-proliferative retinopathy and patients without retinopathy. The mean (± SD) of serum creatinine in patients with proliferative retinopathy, non-proliferative retinopathy and patients without retinopathy had no significant difference.

The presence or absence of retinopathy in the early stages of diabetic kidney disease has not related to renal involvement, in fact, patients without retinopathy may have renal involvement. In periodic examination, diabetic patients should be evaluated for microalbuminuria in addition to renal function test examination.