Corneal Sensitivity
Corneal Nerves:
The Foundation of Ocular Surface Health
The cornea is the human tissue with the highest density of free nerve fiber endings.
The corneal nerves are essential for the ocular surface health, as they trigger 3 key ocular protection mechanisms:
Stimulation of corneal nociceptors by various factors activates neural pathways via the trigeminal nerve (cranial nerve V), relaying signals through the thalamus or cortex. This triggers the lacrimal and meibomian glands, along with conjunctival goblet cells, to secrete aqueous, lipid, and mucin components essential for natural tear production. Corneal nerve injury can follow many threats including mechanical/chemical trauma, infections, and surgeries. Corneal nerves main function is to protect the ocular surface and preserve corneal transparency and vision.
Corneal Sensitivity Impairment in Ocular Conditions
Corneal nerve health can be evaluated by analyzing the function (by esthesiometry or corneal sensitivity testing) or the anatomy and morphology (by in vivo confocal microscopy, IVCF).
Corneal sensitivity impairment (hypersensitivity or hyposensitivity) can compromise the ocular surface healing process and decrease tear production, increasing the risk of corneal deterioration and vision impairment. Corneal sensitivity can be evaluated using an esthesiometer, which allows to quantitatively measure corneal nerve function, allowing timely detection of potential ocular surface damage that requires prompt treatment.
A significant reduction in corneal sensitivity has been reported in multiple ocular conditions:
- Neurotrophic Keratitis
- Dry Eye Disease
- Diabetes
- Anterior Segment Surgery
- Contact Lens
- Glaucoma
Non-Contact Corneal Sensitivity Testing
Non-contact esthesiometry is the test for screening, and monitoring of patients at risk for neurotrophic dysfunction associated with ocular surface disease.
When corneal sensitivity is impaired, neurotrophic damage occurs on the ocular surface that requires advanced therapies.
If Altered corneal sensitivity involves corneal nerve dysfunction that can lead to the development of epithelial defects, ulcerations, corneal perforations and reduced corneolimbic stem cell function.
Corneal Sensitivity Testing Clinical Applications
Non-contact esthesiometry is the test for screening, and monitoring of patients at risk for neurotrophic dysfunction associated with ocular surface disease.
When corneal sensitivity is impaired, neurotrophic damage occurs on the ocular surface that requires advanced therapies.
If Altered corneal sensitivity involves corneal nerve dysfunction that can lead to the development of epithelial defects, ulcerations, corneal perforations and reduced corneolimbic stem cell function.
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