Abstract
Purpose:
To correlate the metabolic status of patients with type 2 Diabetes Mellitus and its relationship with corneal nerve plexus alterations assessed by Confocal Microscopy along with clinical questionnaires to detect peripherial diabetic neuropathy.
Methods:
Patients with type 2 Diabetes Mellitus within the first year of diagnosis were included. All patients were asked for glycosylated hemoglobin (HbA1C). Inclusion criteria included values of glycosylated hemoglobin ≥7%. We excluded patients with diagnosis of central or peripheral neuropathy, ocular disease not related to diabetes or history of previous refractive surgery. A control group of healthy patients were also included. All patients were screened for peripherial neuropathy using the MNSI questionnaire and classified depending on the score obtained as without, mild-moderate or severe peripherial neuropathy. Confocal microscopy was performed to obtain corneal analysis from endothelium to epithelium and four corneal subepithelial nerve plexus parameters were evaluated: Number of fibers, tortuosity of fibers, number of beading and branching grade. Statistical analysis was made using Pearson and t-Student tests, a p ≤ 0.05 was considered statistically significant.
Results:
We included 14 patients in each group. In the study group the mean value of HbA1C was 9.5%. In the study group, 28.5% of the patients were classified as without peripheral neuropathy, 28.5% as mild-moderate peripheral neuropathy and 42.8% as severe peripheral neuropathy. The number of fibers, beadings and the branching grade was decreased in diabetic patients compared with the control group (p = 0.004, p ≤ 0.001 and p = 0.028 respectively). The grade of tortuosity was higher in patients with diabetes compared with healthy subjects with a p ≤ 0.001. There was a tendency of progression of corneal neuropathy with higher levels of HbA1C.
Conclusions:
The assessment of the corneal nerve plexus is a useful tool in the global study of the diabetic patient by establishing the absence or presence of early neuropathic damage, even before clinical manifestations appear.
Keywords: 479 cornea: clinical science •
550 imaging/image analysis: clinical •
596 microscopy: confocal/tunneling