MACULAR RECOVERY-TIME IN DIABETIC CHILDREN WITHOUT RETINOPATHY

The aim of this study was to evaluate whether patients with initial di abetic nephropathy (defined as persistent microalbuminuria) have an im pairment of macular recovery time and if this impairment changes in a long-term follow-up. Eighty insulin-dependent diabetic children withou t fluorescein angiographic signs of retinopathy and 80 controls were i ncluded in the study. All patients underwent nyctometry at the beginni ng of the study; diabetic children repeated the same test after 7 year s. Diabetics were divided into two subgroups as regards presence of pe rsistent microalbuminuria (albumin excretion rate > 20 mu g/min/1.73 m (2)). At the beginning of the study, diabetics as a whole and normoalb uminuric patients showed similar data to controls, while microalbuminu ric ones showed worse data at nyctometry (initial recovery time (IRT): 44.89 +/- 12.50; Summation method (SM): 509.1 +/- 312.0) in compariso n with normoalbuminuric (IRT: 38.12 +/- 10.31, P = 0.010; SM: 648.6 +/ - 272.2, P = 0.036) and control subjects (IRT: 37.77 +/- 11.82, P = 0. 004; SM: 661.5 +/- 297.5, P = 0.013). After 7 years, normoalbuminuric subjects showed a slight, but not significant worsening of nyctometry, while in microalbuminuric ones a significant difference between basel ine and the end of follow-up was found (IRT: 44.89 +/- 12.50 vs. 52.91 +/- 13.9, P < 0.01; SM: 509.1 +/- 312.0 vs. 374.8 +/- 271.9, P < 0.05 ). Diabetic patients had a higher rate of abnormal IRT and SM than con trols (P = 0.0004 and P = 0.0006, respectively). A higher number of pa tients in microalbuminuric subgroup than in normoalbuminuric one were found (both at baseline and at the end of follow-up) above the 95th ce ntile of IRT (baseline 3 vs. 15; P = 0.0002; end of follow-up 5 vs. 23 ; P < 0.0001) and below the 5th centile of SM (baseline 5 vs. 14; P = 0.004; end of follow-up 5 vs. 19; P < 0.0001). Nyctometry was found mo re altered in microalbuminuric patients than in normoalbuminuric and c ontrols. Unfortunately, there is a large overlap between the two diabe tic subgroups and between diabetics and controls; for this reason, thi s technique is not suited for everyday practice.