Colour vision and persistent microalbuminuria in children with type-1 (insulin-dependent) diabetes mellitus: a longitudinal study.

In an attempt to elucidate colour vision in children with type 1 (insulin-dependent) diabetes mellitus without fluorescein angiographic signs of retinopathy, we studied a group of 50 patients of mean age + or - SD 10.27 + or - 2.89 (range 8.1-13.0 years). Results were compared with a sex-and age-matched control group. The Farnsworth-Munsell 100-hue test showed a significantly higher value in total error score (TES) in diabetics than in controls (64.07 + or - 18.32 and 54.27 + or - 12.87, respectively: P = 0.0004). Diabetic patients were divided in two groups as regards presence of persistent microalbuminuria and followed for 7 years. The HbAlc values of the two groups were: normoalbuminuric 7.10 +/- 2.92%, microalbuminuric 9.79 + or - 1.41 (P = 0.004). Microalbuminuric patients showed a significantly higher TES than normoalbuminuric subjects both at the beginning (94.79 + or - 13.98 vs. 58.10 + or - 11.98) and end of the study (103.07 + or - 14.61 vs. 61.04 + or - 13.36: P < 0.0001), and after follow-up they had a worse TES than at the beginning of the study (P = 0.01); no change in TES was found in normoalbuminuric patients during the study. The results suggest that a deficit in colour vision occurs in diabetic children before the onset of fluorescein angiographic signs of retinopathy. Our follow-up shows that microalbuminuric patients present a significant worsening of colour vision. When a patient shows persistent microalbuminuria, colour vision must be carefully evaluated, also in subjects without fluorescein angiographic signs of retinopathy.