Ocular Surface Disease

Diagnosing OSD requires a comprehensive eye examination, often involving several tests:

• Patient history: Understanding the patient’s symptoms, general health, medications, and environmental exposures is crucial.
• Visual acuity test: This assesses how well the patient can see at various distances, with and/or without glasses.
• Slit-lamp examination: A microscope examines the structures of the eye in detail, checking for signs of disease on the ocular surface, particularly inflammation and fluid accumulation (“chemosis”).
• Tear film evaluation: Tests like the Schirmer test measure tear production, while tear film break-up time (TBUT) assesses tear film stability.
• Corneal staining: Special dyes like fluorescein can highlight surface damage to the cornea and conjunctiva.
• Meibomian gland evaluation: Dysfunction of these glands can contribute to dry eye and is assessed through gland expression and imaging. The meibomian glands produce specialized oils (“mebum”) that coat the surface of the tear film to lubricate the blink and reduce evaporation. Meibomian gland disease (MGD) is usually caused by chronic inflammation and/or low-grade infection, and can lead to death of glandular cells, resulting in long-term irreversible damage.

At Kahana Oculoplastic and Orbital Surgery, we have several surgical tools to improve the signs and symptoms of OSD, often getting at the heart of what’s causing the OSD.

• Correction of eyelid malposition: Eyelid conditions such as ectropion (outward turning) or entropion (inward turning) lead to poor protection of the cornea and conjunctiva, poor distribution of tears, lashes rubbing against the cornea, and keratinization of the conjunctiva on the inside of the eyelid (palpebral conjunctiva). Think of the eyelids as being the windshield wipers, and the eye surface as the windshield. If the wipers work poorly, they leave streaks on the windshield that interfere with the view. Likewise with the cornea – if the eyelid blink is poor and the eyelids are poorly fitting, the cornea develops irregularities that interfere with vision. Correcting the eyelid position can improve eye protection, reduce pain and tearing, and visual function. Beyond standard surgical treatments, Dr. Kahana has developed novel techniques that maximize the eyelid’s protective functions.
• Excise redundant conjunctiva: Conjunctivochalasis is a condition in which the skin of the eye becomes thickened, diseased, and starts rolling over itself with every blink. Each blink should be a smooth movement of the eyelid over the ocular surface. But with conjunctivochalasis, the blink causes the conjunctiva to rub abnormally against the rest of the eye, causing chronic irritation. Identifying and excising the abnormal conjunctiva and reconstructing the eye tissues can greatly improve eye symptoms.
• Amniotic membrane patching: Ultra-thick amniotic membrane can be sutured onto the surface of the eye to promote regenerative healing of the cornea and conjunctiva. Often the eye needs to be sutured shut for 3-4 weeks while the tissues heal, so this treatment is performed one eye at a time.
• Lacrimal reconstructive surgery: Sometimes the tear drainage system is blocked or damaged, leading to excessive tearing. In some cases, this contributes to chronic inflammation and even infection of the eye surface, manifesting as mucoid discharge and eye redness. Reconstructive surgery can restore the function of the lacrimal drainage system to improve tear flow and ocular surface health.
• Corneal neurotization surgery: At Kahana Oculoplastic and Orbital Surgery, we are pioneers in the reinnervation of the cornea using nerve grafting. This is a nerve microsurgery performed under a neurosurgical microscope. We have the most experience with this procedure in the Midwest, but success rates exceed 80% in achieving stabilization of the cornea. Please see section on Neurotrophic Keratitis.

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.

Figures: An intra-operative photo of nerve fascicles recruited to re-innervate the damaged cornea & a graphic representation of Corneal Neurotization