Corneal Confocal Microscopy in Patients With Type 1 Diabetes (CCM)

Assessing the use of corneal confocal microscopy to evaluate for early neuropathy changes in subjects with Type 1 Diabetes.

Rationale: Poorly controlled diabetes mellitus is associated with microvascular complications, which includes peripheral neuropathy. Peripheral neuropathy associated with diabetes is a painful condition. Its diagnosis is hampered by painful and long nerve conduction studies which fail to diagnose small nerve neuropathy. It is important to study methods of noninvasive methods of early detection, which are sensitive and specific in diagnosing early neuropathy and we propose a novel study that this can be detected in the cornea of the eye. Aims: Estimate corneal small nerve fiber damage in young T1DM subjects (corneal fiber density, nerve branch density, and fiber length) and compare the results to healthy controls using corneal confocal microscopy (CCM). Estimate corneal nerve fiber damage in subjects with diabetes, with peripheral neuropathy and subjects with diabetes without peripheral neuropathy, diagnosed by skin biopsies and nerve conduction studies Obtain much needed normative values for CCM in adolescents and intraepidermal nerve fiber density from skin biopsies in subjects with type 1 diabetes. As a secondary outcome measure, to compare serum biomarkers including leptin, TNF alpha, and fibrinogen in patients with diabetes in those with neuropathy Vs. without neuropathy.

Estimate corneal small nerve fiber damage in young T1DM subjects and compare the results to healthy controls using corneal confocal microscopy (CCM). This will be done by examining the cornea via confocal microscopy and obtaining images. These images will be evaluated looking at how many nerves there are, how they branch, and how long they are).

Obtain much needed normative values for CCM in adolescents and intraepidermal nerve fiber density from skin biopsies in subjects with type 1 diabetes. This will be done by obtaining a small biopsy of skin and looking at the number of nerve fibers in the outer layer of the skin.

Measuring serum biomarkers (blood levels) leptin. In participants with diabetes, comparing the blood level measurements of those with neuropathy vs. those without neuropathy.

Measuring serum biomarkers (blood levels) Tumor Necrosis Factor (TNF) Alpha. In participants with diabetes, comparing the blood level measurements of those with neuropathy vs. those without neuropathy.

Measuring serum biomarkers (blood levels) fibrinogen. In participants with diabetes, comparing the blood level measurements of those with neuropathy vs. those without neuropathy.

Inclusion: Subjects with diabetes: 18-30 years (cohort 1), adolescents ages 13-17 years (cohort 2). Type 1 Diabetes diagnosed via standard ADA criteria Matched Controls: Match for age and gender Hemoglobin A1c <6.5% Exclusion: For all subjects: Contact lens wearers Diseases that could damage the cornea, other than diabetes. Neurologic disease Psychiatric disease Amputation Foot ulcers Pain not of neuropathic origin. Presence of Lupus, Sjogren's syndrome and Celiac disease Hyperlipidemia requiring lipid-lowering medications Peripheral vascular disease Neuropathy due to anything besides diabetes Presence of any medical condition that may affect nerve conduction (e.g., radiculopathy). For healthy controls Family history of Type 1 Diabetes