Neurotrophic keratitis (NK) is a degenerative corneal disease that results from damage to the trigeminal nerve. The trigeminal nerve is the largest of the 12 cranial nerves, and controls sensation in the face and motor functions like biting and chewing. It also controls corneal tissue metabolism and helps supply trophic factors to the cornea to maintain its health.
When the trigeminal nerve is damaged, it can trigger deterioration of the cornea, including epithelium breakdown, impaired cornea sensitivity, ulcerating perforation, and poor corneal healing.
Neurotrophic keratitis is rare and can be triggered by viruses or chronic diseases. It can be difficult to diagnose and treat.
What Are The Symptoms Of Neurotrophic Keratitis?
Changes to the trigeminal nerve and its relationship to the cornea may occur over time, so patients may not notice symptoms related to neurotrophic keratitis for months or even years after onset. The most common symptom is blurred vision. This could be attributed to several factors, including scarring or fluid buildup from a failing corneal epithelium (the layer that removes excess fluid from the eye). Corneal scarring or ulcers may also lead to eye discomfort.
What Causes Neurotrophic Keratitis?
Corneal nerves are complex, and a number of factors may affect sensitivity. Neurotrophic keratitis, while rare, may be caused by a number of factors, including:
- Viral infections (such as herpes simplex and herpes zoster)
- Chemical burns
- Physical injuries
- Systemic diseases such as diabetes, leprosy, or multiple sclerosis
- Overuse of eye medications or contact lenses
- Tumors or aneurysms that could affect the trigeminal nerve
What Are The Treatments For Neurotrophic Keratitis?
Depending on the severity of the condition, your ophthalmologist may recommend different treatments for neurotropic keratitis. These include:
Preservative Free Topical Lubricants. For some patients, a simple prescription of a topical lubricant to help protect the cornea from further damage may be all that is needed. This treatment may be short- or long-term, depending on how the patient responds.
Punctal Plugs. Punctal plugs are small silicone or temporary collagen plugs inserted into the tear drain located in the eyelid. These aid in retention of your own natural tears, which can be very beneficial for neurotrophic corneas.
Serum Tears. Serum tears are made from your own blood serum that is drawn by the blood bank and made by a compounding pharmacy. These tears are rich in your own body’s proteins and growth factors and facilitate healing in neurotrophic corneas.
Amniotic Membrane. Amniotic membrane patches may be used in treating neurotrophic corneas, especially in severe cases of nonhealing corneal erosions. These are either placed under a bandage contact lens in the office or glued in place in the operating room depending on the severity of the disease.
Scleral Contact Lenses. Scleral contact lenses are larger than conventional contact lenses, which only cover part of the cornea. They are gas permeable, and they are big enough so that the edges rest on the “white” (sclera) of the eye. This means there is less pressure on the cornea, which can protect the cornea and also make the lenses more comfortable to wear. Scleral lenses are also more stable and don’t change with each blink, which can be helpful for more consistent vision.
OXERVATE Eye Drops. This is a new option. OXERVATE is the first FDA-approved treatment for people with neurotrophic keratitis. It contains cenegermin, a recombinant form of human nerve growth factor that is structurally identical to the nerve growth factor naturally produced by your eyes, which is thought to help maintain the nerves that support corneal health.
OXERVATE helps promote tear secretion, improve nerve function, and foster healing of the corneal surface. It also helps corneal epithelial cells and corneal nerves survive and may allow full recovery in some patients.
Eye Lid Surgery (Tarsorrhaphy). This is a surgical procedure where the eyelids are partially sewn together to narrow the opening between them. This means that less of the cornea is exposed, and there is less surface friction when the patient blinks. A tarsorrhaphy can be either permanent or temporary, depending on the condition being treated. This procedure is reserved for severe cases or those who don’t respond to the other treatments.
The cornea specialists at Drs. Campbell, Cunningham, Taylor & Haun thoroughly evaluate each patient and recommend a carefully planned treatment regimen customized to each. Our offices in Knoxville, Farragut, Hardin Valley, Maryville and Sevierville are ready to help.
For an appointment, call (865) 584-0905.