Related Experiment Video
Updated: May 12, 2026
11:29
Corneal Confocal Microscopy: A Novel Non-invasive Technique to Quantify Small Fibre Pathology in Peripheral Neuropathies
Published on: January 3, 2011
Structure-function relationship between corneal nerves and conventional small-fiber tests in type 1 diabetes
Gavasker A Sivaskandarajah1, Elise M Halpern, Leif E Lovblom
1Division of Endocrinology and Metabolism, Department of Medicine, University of Toronto, Toronto, Ontario, Canada.
Diabetes Care
|April 13, 2013
Summary
In vivo corneal confocal microscopy (IVCCM) effectively assesses small nerve fiber structure in diabetic sensorimotor polyneuropathy (DSP). Corneal nerve fiber length, density, and branch density correlate with functional measures, indicating structure-function relationships.
Area of Science:
- Ophthalmology
- Neurology
- Diabetology
Background:
- Diabetic sensorimotor polyneuropathy (DSP) is a common complication of type 1 diabetes.
- Assessing small nerve fiber integrity is crucial for understanding DSP.
- In vivo corneal confocal microscopy (IVCCM) offers a noninvasive method to evaluate corneal nerve morphology.
Purpose of the Study:
- To investigate the structure-function relationship of small nerve fibers in type 1 diabetic subjects with DSP.
- To determine if IVCCM-derived corneal nerve parameters correlate with functional small nerve fiber assessments.
Main Methods:
- Ninety-six type 1 diabetic subjects and 64 healthy controls underwent IVCCM.
- Corneal nerve structure was quantified (corneal nerve fiber length [CNFL], density [CNFD], branch density [CNBD], tortuosity [CNFT]).
- Small nerve fiber function was assessed using cooling detection thresholds (CDTs), laser Doppler imaging flare (LDIFLARE), and heart rate variability (HRV).
Main Results:
- Corneal nerve fiber length (CNFL), density (CNFD), and branch density (CNBD) showed modest correlations with functional tests (rs = 0.25 to 0.41).
- Lower CNFL was associated with poorer functional outcomes (e.g., higher CDT, lower LDIFLARE, lower HRV).
- Corneal nerve fiber tortuosity (CNFT) did not show significant associations with functional measures.
Conclusions:
- IVCCM-assessed small nerve fiber morphology correlates with functional measures of nerve injury in DSP.
- CNFL, CNFD, and CNBD are valuable parameters for evaluating structure-function relationships in diabetic neuropathy.
- IVCCM is a promising tool for noninvasive assessment of small fiber neuropathy in diabetes.
Related Concept Videos
01:24Local Anesthetics: Differential Sensitivity of Nerve Fibers
Local anesthetics (LAs) block the sodium channels of nerve trunks, sensory nerve endings, and neuromuscular junctions. Although LAs can block all kinds of nerves, the sensitivity of nerve fibers differs according to nerve types and structures. LAs are known to block myelinated fibers faster than unmyelinated ones. Also, they block pain or sensory neurons at low concentrations without affecting the motor neurons involved in muscle contractions. This helps relieve labor pain without affecting the...
01:26Type I Diabetes II: Pathophysiology
Type 1 diabetes mellitus arises from an immune-mediated destruction of pancreatic β-cells, resulting in an absolute deficiency of insulin. This process develops in genetically susceptible individuals when autoimmunity, environmental exposures, and immunologic dysregulation converge to trigger a targeted attack on the insulin-producing cells of the pancreas. The β-cells are located within the islets of Langerhans and are essential for regulating blood glucose by facilitating cellular uptake of...
01:22Diabetic Neuropathy
DefinitionDiabetic neuropathy is nerve damage caused by long-standing diabetes mellitus. It results directly from prolonged high blood sugar levels.PathophysiologyThe pathophysiology of diabetic neuropathy involves both metabolic and vascular disturbances triggered by chronic hyperglycemia.Metabolic injury: Elevated glucose levels activate the polyol pathway within nerve cells, leading to the accumulation of sorbitol and fructose. This increases oxidative stress, disrupts normal nerve...
01:12Type I Diabetes I: Introduction
Type 1 diabetes mellitus is a chronic metabolic disorder characterized by an absolute deficiency of insulin resulting from the autoimmune destruction of pancreatic β-cells. Although it can occur at any age, it is most commonly diagnosed in childhood, adolescence, or early adulthood. The loss of insulin production impairs cellular glucose uptake, resulting in persistent hyperglycemia and necessitating lifelong insulin therapy.Autoimmune Destruction of β-CellsThe hallmark of type 1 diabetes is an...
01:22Diabetes Mellitus: Overview and Type I Subtype
Diabetes mellitus is a chronic metabolic disorder characterized by high blood glucose levels due to inadequate insulin production, insulin resistance, or both. The condition affects millions worldwide and can significantly impact their health and quality of life.
Type 1 diabetes is an autoimmune disease in which the immune system mistakenly attacks and destroys the insulin-producing beta cells in the pancreas. As a result, the body is unable to produce sufficient insulin, and individuals with...
Type 1 diabetes is an autoimmune disease in which the immune system mistakenly attacks and destroys the insulin-producing beta cells in the pancreas. As a result, the body is unable to produce sufficient insulin, and individuals with...
01:24Type II Diabetes II: Pathophysiology
PathophysiologyType 2 diabetes mellitus (T2DM ) is a chronic metabolic disorder characterized by insulin resistance and progressive pancreatic β-cell dysfunction, leading to impaired glucose homeostasis. It results from interactions among genetic predisposition, environmental factors, and metabolic stressors, such as overnutrition and a sedentary lifestyle.Insulin Resistance and Glucose DysregulationEarly T2DM involves insulin resistance in skeletal muscle, adipose tissue, and the liver.