Effect of microalbuminuria on corneal endothelium in patients with diabetes without retinopathy

BACKGROUND: The aim of this study was to investigate the effect of microalbuminuria on corneal endothelium in patients with diabetes without retinopathy. METHODS: This cross-sectional study comprised 100 patients with type 2 diabetes mellitus (DM) without diabetic retinopathy and 92 control subjects without diabetes. Forty-five patients had microalbuminuria and 55 subjects were microalbuminuria negative. Endothelial measurements were obtained using specular microscopy. Endothelial cell density, average area, co-efficient of variation, maximum area, minimum area, hexagonality and corneal thickness were compared between the groups on the basis of microalbuminuria, DM duration and medication, HbA1c , body mass index, serum lipid and protein profiles, hypertension and hyperlipidaemia diagnosis. RESULTS: There were no significant differences in age, gender, endothelial cell density, average area, co-efficients of variation, maximum area, minimum area, hexagonality or corneal thickness among the microalbuminuria positive, microalbuminuria negative and control groups (p > 0.05). However, microalbuminuria positive patients had lower high-density lipoprotein levels than the microalbuminuria negative patients (p = 0.042). DM and control groups showed similar endothelial measurements (p > 0.05). Patients with a HbA1c > 7 per cent (53 mmol/mol) had lower hexagonality value (p = 0.039) than in the subjects with a HbA1c ≤ 7 per cent. No significant differences were found in endothelial parameters when groups were compared based on DM duration, medication and co-morbidities. CONCLUSIONS: Microalbuminuria positive and negative patients with DM without retinopathy seem to have similar corneal endothelial measurements with controls. However, patients with a HbA1c > 7 per cent should be monitored for deterioration in corneal endothelial cell morphology even without diabetic retinopathy, which might be critical prior to anterior segment surgery.