Corneal Diseases and Surgery
The
cornea is the eye’s built-in protector. It is clear and, along with
the white of the eye (the sclera), provides a barrier against dirt,
germs, and other things getting into your eye. It even screens out
some of the ultraviolet radiation that would otherwise enter your
eye.
The cornea also plays a key role in your vision quality. Your cornea
bends light as it enters your eye; the accuracy of this bending is
how well you see objects at different distances.
The cornea can be affected by various diseases and conditions. The
common causes of these are infections, trauma, degenerative
disorders, autoimmune disorders, nutritional deficiencies, growths,
ectasia (thinning), and allergies. At Longwood Eye we provide
treatment and surgery for many of these diseases.
What Corneal Diseases and Conditions Does Longwood Eye Treat?
These are the corneal diseases we treat:
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Blepharitis
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Dry Eye Syndrome
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Penetrating keratoplasty
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Anterior Stromal Micropuncture
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Pterygium Excision with Graft
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Amniotic Membrane Graft
What Are the Signs and Symptoms of Corneal Disease?
Problems with the cornea often show themselves with redness around
the cornea and/or corneal cloudiness. These are common symptoms:
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Visual impairment, such as blurred or cloudy vision
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Severe pain in the eye
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Tearing
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Sensitivity to light
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Headaches, nausea, fatigue
How Does Longwood Eye Diagnose Corneal Diseases?
We employ a variety of tests and tools to diagnose diseases/problems
with your cornea. Beyond a careful visual exam of your eyes and
eyelids, and a review of your medical history, we’ll check the
cornea with a slit lamp microscope. The slit lamp allows us to
examine the anterior segment and posterior segment of the eye,
including the eyelid, sclera, conjunctiva, iris, natural crystalline
lens, and the cornea.
Additional testing may include:
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Topography and keratometry to study the shape of the cornea
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Pachymetry to measure the thickness of the cornea
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Microscopy to assess the health of the endothelial cells and
identify infections
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Tear film assessment
Blepharitis
Blepharitis is an inflammation of the eyelids. This usually occurs
when tiny oil glands located near the base of the eyelashes become
clogged. This irritates the eyes, making them red. Several diseases
and conditions can cause blepharitis, and it can be chronic and
difficult to treat. Fortunately, it doesn’t usually cause damage to
your vision.
How We Diagnose Blepharitis
An examination of your eyelids, looking for clogged glands is the
first diagnosis step. We may swab your skin to sample the oil and
crust on your eyelid. This can give us an idea what’s behind the
inflammation, be it an allergen, bacteria, or fungi.
How We Treat Blepharitis
Washing the eyes in warm water with a focus on the eyelids and using
warm compressions can often open these clogged glands. Beyond that,
we may use prescription medications:
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Medications to address the infection — Antibiotics applied to
the eyelids can resolve bacterial infections.
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Medications to control inflammation — Steroid eyedrops and
ointments can control inflammation.
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Treatments for underlying conditions — Blepharitis caused by
other issues such as rosacea, seborrheic dermatitis, and other
diseases can be treated by targeting the disease to resolve the
blepharitis.
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Medications that target the immune system — Topical cyclosporine
is a calcineurin inhibitor that can relieve this condition.
Dry Eye
As the name implies, dry eye is a condition that occurs when your
eyes aren’t providing adequate lubrication for your eyes. Your tears
may be either of poor quality or you simply may not produce enough
of them. Dry eye makes your eyes sting and burn. The eyes will
become red, sensitive to light, and it can feel as if there is
something in the eyes. Treatment often may be ongoing.
How We Diagnose Dry Eye
To diagnose dry eye we will perform a comprehensive eye exam first.
From there we may:
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Measure the volume of your tears — This is done
using the Schirmer test. Blotting strips are placed under your
lower eyelids. After five minutes we measure the portion of the
strip that has been soaked by your tears.
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Determine the quality of your tears — We next
test the surface condition of your eyes. Using special dyes, we
look for staining patterns on the cornea. We also measure how
long it takes your tears to evaporate.
How We Treat Dry Eye
Treating dry eye may be as simple as providing artificial tears for
the patient to use. In other cases, we may have to manage another
condition that is causing your dry eye. Other treatments look to
improve tear quality or stop your tears from draining too quickly.
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Prescription medications — Medications we may
use range from those to reduce eyelid inflammation or control
cornea inflammation, to tear-stimulating drugs and eye inserts
that dissolve and release lubrication.
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Surgery — We may partially or completely close
your tear ducts by inserting tiny silicone plugs.
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Light therapy and eyelid massage — Directing
intense pulsed light, followed by eyelid massage, can be
effective for severe dry eye.
Penetrating Keratoplasty
If the cornea has been damaged, a cornea transplant, clinically
known as keratoplasty, may be necessary. A cornea transplant can
restore vision, reduce pain, and improve the appearance of the
damaged cornea.
Many conditions can merit a cornea transplant:
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Thinning of the cornea
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An outwardly bulging cornea
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Fuchs’ dystrophy
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Cornea scarring from infection or injury
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Clouding of the cornea
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Swelling of the cornea
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Corneal ulcers
Cornea Transplant Surgery
The most common type of corneal transplant is called penetrating
keratoplasty. Your Longwood Eye surgeon uses an instrument
known as a trephine, to cut a small circular disc from the diseased
or abnormal cornea. Then precisely measured donor cornea tissue is
placed in the hole. This is known as a full-thickness corneal
transfer. It is a very successful surgery with low risk.
Anterior Stromal Micropuncture
Recurrent corneal erosion syndrome (RCES) is a common disorder
involving the corneal epithelium (the outer layer) and the
epithelial basement membrane. This condition is characterized by
repeated breakdown of the epithelium and causes moderate to severe
eye pain and can lead to corneal scarring and vision changes. The
recurrent part of the title means this can happen even multiple
times each week, where the epithelium erodes, regrows, and erodes
again. RCES can be caused by an old injury or abrasion of the eye,
or an inherited eye disease.
How We Treat RCES
There are three layers in the front of the cornea. The outer layer,
the epithelium, is constantly replacing its cells, not unlike our
skin. The second layer behind that is the Bowman layer, which is the
layer the epithelium should stick to. Behind the Bowman layer is the
stroma layer, the main thickness of the cornea.
In an anterior stromal micropuncture, your Longwood Eye surgeon takes
a specialized needle and makes tiny punctures through the
epithelium, through the Bowman layer, and just barely enters the
stroma. These punctures create very small scars that help improve
the adhesion from the epithelium and decrease the recurrence of
erosions.
This is usually done on the areas of the cornea outside the center,
to avoid too much scarring in the center of the vision.
Pterygium
Pterygium is an eye condition that affects people who spend a great
deal of time outdoors. It involves the growth of pink, fleshy tissue
on the conjunctiva (white part of the eye), usually on the side
toward the nose. The cause of pterygium is excessive exposure to
ultraviolet light, dust, wind, sand, and humidity. Those
characteristics lead to its colloquial name, surfer’s eye.
Pterygium is a non-cancerous growth that can develop slowly over
time and may not present a threat to the patient’s eyesight, unless
it covers the pupil of the eye. Only if it interferes with the
patient’s eyesight is surgery needed. This is because pterygium
tends to regrow.
How Is Pterygium Surgery Performed?
At Longwood Eye, we may use one of two methods for pterygium
surgery. The goal is to stop or at least thoroughly hinder the
regrowth of pterygium.
Pterygium Excision with Graft
This is the procedure we use to remove the abnormal growth on the
sclera. Prior to adding the graft, this surgery, known as the bare
sclera technique, resulted in a hole on the surface of the
conjunctiva that made it likely to regrow pterygium again in the
future. But now, a tissue graft taken from the underside of the
eyelid corrects this problem.
The patient is under local anesthesia for this surgery — both light
oral sedation and local anesthesia on the eye itself. Then the
pterygium is excised along with a portion of the surrounding
conjunctival tissue. Next, the area where the growth was removed is
then scraped with a blade and an abrasive burr to remove any
remaining vascular attachments that may remain where the growth was.
Then the graft is taken and placed on the excision site. It is
placed with an adhesive mixture, usually thrombin and fibrinogen.
Amniotic Membrane Grafting
As in the above method, the pterygium is excised along with a
portion of the surrounding conjunctival tissue. Instead of a graft,
freeze-dried human amniotic membrane tissue is placed onto the bare
sclera. We place and adhere this to the sclera with fibrinogen.
There is conflicting research on whether the likelihood of regrowth
is better or about the same with the amniotic membrane method or the
excision with graft method. Both have a dramatically lower
recurrence, however, than the bare sclera technique.
What Are the Risks of Corneal Surgery?
Cornea transplants, stromal micropuncture, and pterygium surgeries
are considered to be relatively safe procedures. However, there are
risks. These include:
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Bleeding
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Infection
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Swelling
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Clouding of the lens
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Later cataract development
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Increased intraocular pressure (inside the eye)
Schedule A Consultation
If you are suffering from a corneal disease and would like to learn
more about your surgical options, contact our
office today! Call (800)
676-5050 to schedule a consultation.