Understanding Neurotrophic Keratitis: Causes, Symptoms, and Its Impact on Vision.

Understanding Neurotrophic Keratitis: Causes, Symptoms, and Its Impact on Vision

By Dean S. Steinberger, OD

Neurotrophic keratitis (NK) is a rare but serious degenerative disease of the cornea caused by impaired corneal innervation. Because the cornea relies heavily on sensory nerve input for healing and protection, any reduction in corneal sensation can set off a cascade of ocular surface problems—sometimes leading to persistent epithelial defects, ulceration, and even vision-threatening complications if left untreated.

This condition is often underdiagnosed, yet early identification and intervention can significantly improve outcomes. In this blog, we’ll explore the causes, symptoms, stages, and modern treatment options for neurotrophic keratitis, along with how it impacts the eye long term.

What Is Neurotrophic Keratitis?

Neurotrophic keratitis occurs when the trigeminal nerve, which supplies sensation to the cornea, is damaged. Without normal corneal sensation, the eye loses its ability to detect dryness, injury, or irritation—meaning the cornea does not heal properly and becomes more vulnerable to breakdown.

For more clinical background, you can reference the American Academy of Ophthalmology (AAO):
🔗 https://www.aao.org

Common Causes of Neurotrophic Keratitis

NK may result from a variety of systemic, surgical, infectious, or neurological conditions. Some of the most common include:

  • Herpes simplex or herpes zoster infections affecting the corneal nerves
    🔗 https://www.cdc.gov/shingles

  • Ocular surgeries, especially refractive procedures, corneal transplants, or tumor removal

  • Chronic contact lens wear

  • Diabetes, which may cause peripheral nerve damage
    🔗 https://www.niddk.nih.gov/health-information/diabetes

  • Neurological conditions, such as stroke, multiple sclerosis, or tumors affecting the trigeminal nerve

  • Long-term topical medication toxicity

How Neurotrophic Keratitis Affects the Eye

Because the cornea no longer receives appropriate nerve signals, the eye’s natural healing mechanisms slow dramatically. This can lead to:

1. Reduced Tearing and Blinking

Normal tear production and blink reflexes rely on corneal sensation. In NK, both can be diminished, resulting in dry eye–like symptoms that worsen the ocular surface.

2. Persistent Epithelial Defects

The corneal epithelium struggles to heal, causing chronic non-healing defects. This increases the risk of infection or thinning.

3. Corneal Ulceration

If defects deepen, the cornea may begin to erode or ulcerate, creating a sight-threatening emergency.

4. Scarring and Vision Loss

Without treatment, ulceration and thinning can lead to scarring, perforation, or permanent loss of vision.

For more information on corneal health, see the National Eye Institute (NEI):
🔗 https://www.nei.nih.gov

Stages of Neurotrophic Keratitis

NK is commonly classified into three stages:

Stage 1:

  • Punctate epithelial erosions

  • Dry eye–like symptoms

  • Mild irregularity of the corneal surface

Stage 2:

  • Persistent epithelial defects

  • Stromal edema

  • Increased risk for scarring

Stage 3:

  • Corneal ulceration

  • Stromal melting

  • Possible perforation (emergency)

Diagnosis

Diagnosis typically involves:

  • Corneal sensitivity testing

  • Slit-lamp examination

  • Fluorescein staining

  • Review of medical and surgical history

A thorough evaluation helps determine the stage of NK and guide treatment.

Treatment Options

Treatment varies depending on severity, but may include:

1. Lubrication and Protection

  • Preservative-free artificial tears

  • Ointments

  • Punctal plugs

  • Moisture chamber goggles

2. Discontinuation of Toxic Medications

Stopping chronic topical medications that may be causing epithelial toxicity.

3. Therapeutic Contact Lenses

Such as bandage lenses or scleral lenses to protect the cornea and promote healing.

4. Autologous Serum Tears

Rich in growth factors that support corneal repair.

5. Cenegermin (Oxervate)

An FDA-approved recombinant nerve growth factor eye drop that stimulates corneal nerve healing.
🔗 https://www.fda.gov (search “Cenegermin”)

6. Surgical Interventions

For advanced disease:

  • Amniotic membrane transplantation

  • Tarsorrhaphy (partial eyelid closure)

  • Corneal transplantation in severe cases

Long-Term Outlook

Early diagnosis leads to the best outcomes. While NK can be chronic, modern therapies—especially biologic treatments like cenegermin—offer new hope for restoring corneal integrity and preventing long-term damage.

Patients should maintain close follow-up with their eye care provider, especially if they have risk factors such as diabetes, a history of ocular herpes, or prior ocular surgery.

Final Thoughts

Neurotrophic keratitis is a condition that requires prompt attention, careful monitoring, and personalized treatment. By understanding the underlying causes and recognizing symptoms early, patients and clinicians can work together to protect vision and maintain long-term corneal health.

If you suspect you may be experiencing symptoms of NK or have risk factors associated with corneal nerve damage, schedule a comprehensive eye examination as soon as possible.

Written by:
Dean S. Steinberger, OD

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