Keratocyte density is reduced and related to corneal nerve damage in diabetic neuropathy

Abstract

PURPOSE. The purpose of this study was to assess the relationship between corneal keratocyte density (KD) and corneal nerve damage in patients with and without diabetic peripheral neuropathy. METHODS. Eighty-six patients with type 1 and type 2 diabetes and 21 age-matched control subjects underwent assessment of the neuropathy disability score, quantitative sensory testing, electrophysiology, and corneal confocal microscopy and were divided into those without (DN-) (n = 22) and with (DN+) (n = 64) diabetic neuropathy. Corneal sub-basal nerve parameters and KD in the anterior, mid, and posterior stroma were quantified. RESULTS. Anterior, mid, and posterior stromal KD were significantly reduced in DN- (P = 0.02, P = 0.009, P = 0.01, respectively) and DN+ (all P < 0.0001) subjects compared to controls. Corneal nerve branch density (CNBD) (P < 0.0001, P < 0.0001) and corneal nerve fiber length (CNFL) (P = 0.03, P < 0.0001) were significantly reduced in DN- and DN+ subjects, respectively, and corneal nerve fiber density (CNFD) (P < 0.0001) was significantly reduced only in DN+ subjects compared to controls. Anterior, mid, and posterior stromal KD correlated significantly with CNFD (P = 0.008, P = 0.005, P = 0.01), CNBD (P = 0.01, P = 0.006, P = 0.001), and CNFL (P = 0.04, P = 0.008, P = 0.003), respectively. CONCLUSIONS. This study demonstrates a reduction in anterior, mid, and posterior KD, which is associated with corneal sub-basal plexus nerve damage in patients with diabetes.