Corneal Nerve Loss In Children With Type 1 Diabetes Mellitus Without Retinopathy Or Microalbuminuria

Aims/Introduction Corneal confocal microscopy is a rapid, non-invasive ophthalmic technique to identify subclinical neuropathy. The aim of this study was to quantify corneal nerve morphology in children with type 1 diabetes mellitus compared with age-matched healthy controls using corneal confocal microscopy. Materials and Methods A total of 20 participants with type 1 diabetes mellitus (age 14 +/- 2 years, diabetes duration 4.08 +/- 2.91 years, glycated hemoglobin 9.3 +/- 2.1%) without retinopathy or microalbuminuria and 20 healthy controls were recruited from outpatient clinics. Corneal confocal microscopy was undertaken, and corneal nerve fiber density (n/mm(2)), corneal nerve branch density (n/mm(2)), corneal nerve fiber length (mm/mm(2)), corneal nerve fiber tortuosity and inferior whorl length (mm/mm(2)) were quantified manually. Results Corneal nerve fiber density (22.73 +/- 8.84 vs 32.92 +/- 8.59;P < 0.001), corneal nerve branch density (26.19 +/- 14.64 vs 47.34 +/- 20.01;P < 0.001), corneal nerve fiber length (13.26 +/- 4.06 vs 19.52 +/- 4.54;P < 0.001) and inferior whorl length (15.50 +/- 5.48 vs 23.42 +/- 3.94;P < 0.0001) were significantly lower, whereas corneal nerve fiber tortuosity (14.88 +/- 5.28 vs 13.52 +/- 3.01;P = 0.323) did not differ between children with type 1 diabetes mellitus and controls. Glycated hemoglobin correlated with corneal nerve fiber tortuosity (P < 0.006) and aspartate aminotransferase correlated with corneal nerve fiber density (P = 0.039), corneal nerve branch density (P = 0.003) and corneal nerve fiber length (P = 0.037). Conclusion Corneal confocal microscopy identifies significant subclinical corneal nerve loss, especially in the inferior whorl of children with type 1 diabetes mellitus without retinopathy or microalbuminuria.