The ocular surface consists of the cornea (clear window to the eye), conjunctiva (skin of the eye), and the tear film that protects and hydrates the cornea and conjunctiva. The ocular surface is extremely complex, anatomically and physiologically. Disorders of the ocular surface are the most common of all eye conditions, and include dry eye, conjunctivitis, corneal scarring, superior limbic keratoconjunctivitis, or stem cell deficiency secondary to ocular cicatricial pemphigoid, Stevens Johnson Syndrome, or another degenerative conditions. Symptoms of ocular surface disease include pain, irritation, redness, blurry vision that goes in and out, mucous discharge and lashes that rub on the eye. Treatment requires a careful evaluation to achieve a proper diagnosis. There are many different surgical and non-surgical approaches to treating ocular surface disease, from ocular lubrication to ocular surface reconstruction.
The cornea – the clear part in the front of the eye – is a unique biological tissue in that it has no blood vessels and is optically clear. The clarity of the cornea is a fundamental aspect of vision; without this clarity, good vision is impossible.
While the cornea lacks blood vessels and mostly obtains its oxygen supply directly from the air, it is very rich in innervation. It is among the most highly innervated tissues in the body, and even minor injuries to the cornea can be terribly painful (e.g. corneal scratch). Fortunately, the cornea is also the fastest healing tissue in the body. The ability of the cornea to heal requires special biological signals from the nerves. This signals – neurotrophic molecules – stimulate the cells of the cornea to divide and reform the damaged tissue.
Neurotrophic keratitis is a disorder in which the cornea has lost its nerves. There are many causes to neurotrophic keratitis, including chronic trauma from dry eyes, chronic inflammation, herpes infection, and even congenital absence of the nerve.
A major medical advance of the past decade has been the development of techniques to reinnervate the cornea. These include both medical (eye drops) and surgical (corneal neurotization). The eye drops (cenegermin-bkbj, known as Oxervate) are most useful when the denervation is distal and fairly recent, caused by chronic dry eyes. Otherwise, surgery is required.
A graphic representation of Corneal Neurotization
An intra-operative photo of nerve fascicles recruited to re-innervate the damaged cornea
Corneal neurotization surgery uses a nerve graft from a cadaver to connect a good nerve from around the eye (e.g. supraorbital n., infraorbital n.) to the cornea. The technique is tricky, and Dr. Kahana performs it using a neurosurgical microscope. Dr. Kahana is a pioneer of corneal neurotization in Michigan, including performing the first neurotization surgery in an infant born without a corneal nerve. As one of the most experienced corneal neurotization surgeons in the Midwest, Dr. Kahana is referred patients who suffer from neurotrophic keratitis from throughout the Midwest.
This is a truly revolutionary technique for treating a vision- and eye-threatening condition.
Corneal neurotization can be a true miracle for some patients. Dr. Kahana is the only surgeon in Michigan, and one of the few in the world, who performs this groundbreaking surgery.
The first is a photo of a patient with an opaque cornea following a shingles viral infection of the eye. The patient lost essentially all useful vision. Attempts to improve the cornea failed because the virus damaged the nerve that maintains the health and transparency of the cornea. The second photo is of the same patient 18 months after a corneal neurotization surgery, in which Dr. Kahana created a brand new nerve for the cornea, followed a year later with a corneal transplant procedure by an expert cornea surgeon. This time, the cornea healed because the new nerve is functional, and the transplant “took.” The patient has good vision out of this previously blind eye.
This man was found to have a mass of the right conjunctiva following his cataract surgery and referred for biopsy, which revealed amyloidosis. He then underwent excision of the amyloidosis with reconstruction using a buccal mucous membrane graft as well as umbilical cord graft. The postoperative photo was taken 1 month after surgery.
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Oculoplastic, Orbital and Eyelid Surgery in Livonia & Ann Arbor, MI.
Copyright 2022 | Design by Pro Media.
Oculoplastic, Orbital and Eyelid Surgery in Ann Arbor & Novi, MI.