RESUMEN
PURPOSE: To evaluate the correlation between the severity of diabetic retinopathy, decrease of corneal sensitivity and conjunctival impression cytology. METHODS: 150 eyes of 75 patients were enrolled. The patients were divided into two groups. The study group is 110 eyes of 55 patients with diabetic retinopathy and the control group is 40 eyes of 20 patients without diabetic retinopathy. The hemoglobin A1C (HbA1C) and fasting plasma glucose (FPG) were measured for the index of diabetic control. Corneal sensitivity was measured with Cochet-Bonnet aesthesiometer, and conjuctival impression cytology and fundus examination were done in two groups after topical anesthesia instillation. The classification of diabetic retinopathy was based on the ETDRS. RESULTS: In corneal sensitivity, the study group was 3.8 +/- 3.6 g/mm2, the control group 1.1 +/- 2.16 g/mm2, showing statistically significant difference (p<0.05). The severity of diabetic retinopathy had negative correlation with corneal sensitivity (R2=0.26, p<0.05). Conjunctival impression cytology had negative correlation with corneal sensitivity (R2=0.41, p<0.05), and positive correlation with retinopathy (R2=0.26, p<0.05). Corneal sensitivity was affected by the hemoglobin A1C (p<0.01), but fasting plasma glucose (p=0.7). CONCLUSIONS: Conjucntival impression cytology had negaitive correlation with corneal sensitivity and positive correlation with diabetic retinopathy. It can be thought that corneal sensitivity is affected by chronic glycemic control.