Understand neurotrophic keratitis (NK) beyond the ocular surface

LOSS OF CORNEAL SENSITIVITY IS THE HALLMARK OF NK1

To learn what causes neurotrophic keratitis (NK) and identify it as early as possible, we must know the role of the corneal nerve in maintaining ocular surface homeostasis.1

What is NK Importance of Corneal Sensitivity

What is NK

What is NK

A DEGENERATIVE DISEASE CAUSED BY CORNEAL NERVE DAMAGE

Neurotrophic keratitis (NK) is defined as a rare disease, and can be mistaken for more common conditions, such as dry eye disease.1,2

A key differentiator between NK and other ocular conditions is the reduction or total loss of corneal sensitivity. This loss is caused by damage to the corneal nerve, which leads to breakdown and poor healing of the innervated corneal epithelium. This, in turn, leads to a lack of nourishment that is essential to the survival, differentiation, and maturation of corneal nerve fibers.3

Importance of Corneal Sensitivity

IMPORTANCE OF CORNEAL SENSITIVITY

CORNEAL NERVES
HELP MAINTAIN HOMEOSTASIS

By providing nourishment to the ocular surface and stimulating protective reflexes, such as blinking and tear production, healthy corneal nerves help maintain corneal integrity and homeostasis. Corneal sensitivity is a key indicator of corneal nerve function.3

Ocular surface homeostasis is maintained by an intricate feedback loop of corneal nerves, the lacrimal gland, and the corneal epithelium.1,3

Select each number to learn about the steps involved in maintaining ocular surface homeostasis.

Corneal nerves send sensory information to the brain.1

The brain sends signals back via the lacrimal and motor nerves, creating a feedback loop that stimulates protective reflexes, such as tear production and blinking.1,3

Below the ocular surface, corneal nerve fibers release neuromediators that promote nourishment to the cornea and stimulate healing.3

Corneal epithelial cells and keratocytes release nerve growth factor (NGF) and neuropeptides to help maintain ocular surface homeostasis by supporting the survival and maturation of corneal nerve fibers (as shown in preclinical models).3,4

FROM HOMEOSTASIS TO NK PROGRESSION

Healthy corneal nerves help maintain ocular surface integrity.3 But when the nerves are damaged, the feedback loop is disrupted, setting off a cascade of events that may lead to progressive damage to the ocular surface.3

Learn About NK Progression

References: 1. Dua HS, Said DG, Messmer EM, et al. Neurotrophic keratopathy. Prog Retin Eye Res. 2018;66:107-131. 2. Sacchetti M, Lambiase A. Diagnosis and management of neurotrophic keratitis. Clin Ophthalmol. 2014;8:571-579. 3. Mastropasqua L, Massaro-Giordano G, Nubile M, Sacchetti M. Understanding the pathogenesis of neurotrophic keratitis: the role of corneal nerves. J Cell Physiol. 2017;232(4):717-724. 4. Müller LJ, Marfurt CF, Kruse F, Tervo TMT. Corneal nerves: structure, contents and function. Exp Eye Res. 2003;76(5):521-542.