Diabetic microvasculopathy: the renal-retinal link

Manifestations of diabetic microvasculopathy are protean. Graded increases in the severity are recognised in both nephropathy and retinopathy. This study was undertaken with 100 patients of type 2 diabetes mellitus to evaluate how far these graded increments could be linked at each stage and in each patient. The renal parameters studied were the various accepted levels of albuminuria; the retinopathy parameters ranged from normal retina to severe proliferative stages. Corresponding grades were proposed and altered, if required, to reach the best possible correlation. The correlation was attempted though the common link of mean glomerular filtation rates at each level and the concordance of either parameter grade in an individual patient. The correlations of the mean glomerular filtration rate for all propositions of severity were significant. However, there was significant variability of the parameters in an individual patient. This was more with less severe grades but diminished with increased duration. The predictive value of one lesion for the other was low in cases with shorter duration and less severe grades. Probably, shorter duration patients have an interplay of both genetic factors and the assault of the risk factors while in longer duration patients the cumulative risk exposure play the dominant role.