Introduction
Pterygium is a fleshy, triangular-shaped overgrowth present on the conjunctiva of the eye. Conjunctiva is the transparent membrane that covers the white portion of the eye. It gets affected by prolonged exposure to ultraviolet light. It is not cancerous and usually does not cause severe symptoms leading to loss of vision. Most individuals affected by pterygium do not require any treatment unless the overgrowth causes an interference in the vision.
What Is Pterygium?
Pterygium is derived from the Greek word ‘Pteryx,’ meaning ‘wing,’ and ‘Pterygion,’ meaning ‘fin.’ It is a wing-shaped structure on the conjunctival tissue. It grows gradually and sometimes might grow large enough to cover the pupil, which is the black portion of the eye. When it affects both eyes simultaneously, it is called a bilateral pterygium. The pterygium will remain in the eyes throughout, growing slowly or stopping to grow suddenly.
What Are the Causes of Pterygium?
Pterygium is caused mainly by a long period of exposure to the sun’s ultraviolet rays. Anyone who spends more time under the sunlight can develop the condition. It can also occur when the eye is exposed to dust, wind, pollen, and hot and dry weather. It is a rare disease affecting only 12 % of the world’s population. Of the people affected, it is most commonly seen in older patients above 80 years of age.
What Are the Signs and Symptoms of Pterygium?
The pterygium might show no symptoms in a few individuals. If symptoms develop, they may be mild or severe.
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A fleshy pink growth in the eye.
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Itchiness or irritation within the eyes due to dryness.
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Redness and swelling of the eye.
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Feeling of sand or dirt within the eye.
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Inability to wear contact lenses.
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Teary eyes.
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A bulgy appearance of the eye due to overgrowth.
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The vision gets interfered causing blurred or double vision.
How to Diagnose a Pterygium?
The following are the tests done by an ophthalmologist to examine and confirm the diagnosis of the growth in the eye.
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Slit Lamp Examination: A microscope with a bright light is used to examine the structures around the eyes in detail. This allows the doctor to detect the involvement of the overgrowth and any damage caused to the adjacent structures.
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Photo Documentation: Photographs of the eye with the growth are taken to check the progress and the rate at which it grows.
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Visual Acuity Test: It is a routine eye examination where the individual is checked for distant and near vision by reading out the letters being displayed at a required distance.
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Corneal Topography: A detailed examination of the cornea providing information about the shape, power, and condition of the corneal surface. It creates a three-dimensional display of the corneal image on the computer screen.
What Is the Treatment for Pterygium?
The treatment for pterygium is started initially with a symptomatic treatment wherein the doctor prescribes eye drops to reduce the redness. The treatment limited to medications alone is in cases where pterygium is less than three millimeters in size and not involving the pupil or disturbing the vision. The main cause of pterygium forming is exposure to ultraviolet rays from the sunlight. Hence, the patient is advised to wear sunglasses while stepping outdoors to shield the eye against ultraviolet rays. Surgical management is required when the growth is about three millimeters or above. The surgical intervention is indicated in the following situations:
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When there is severe irritation to the eyes, causing redness and a burning sensation.
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If the patient complains of astigmatism (blurred vision) for distant and near objects.
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If the growth keeps increasing in size and spreads across the pupil.
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If the growth is large and causes an aesthetic appearance to the eyes, surgery is performed to remove the overgrowth and improve the cosmetic appearance.
It is up to the decision of the doctor to determine whether the patient must undergo surgery or can be treated with medications alone. A detailed eye examination provides the necessary information regarding the overgrowth, and an appropriate treatment protocol is planned accordingly.
How Does Surgical Intervention Manage Pterygium?
No particular surgery is universally accepted as a standard surgery for pterygium. Different techniques are available, which are used according to the patient’s condition. The basic aim for all surgeries is the excision (complete surgical removal) of pterygium. The surgery is completed in 30 to 45 minutes. The doctor administers local anesthesia to the eye to cause numbness and for a painless procedure. The area around the eye is cleaned with an antiseptic solution to reduce the risk of infection. The surgeon carefully removes the pterygium along with the conjunctival tissue. After the complete removal of the pterygium, a graft is placed on the operation site to prevent its recurrence. The various surgical techniques that are employed are:
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Bare Sclera Technique: The pterygium is removed surgically without replacing the site with a graft. The white portion of the eye under the pterygium is allowed to heal on its own. This technique is associated with a high risk of recurrence.
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Conjunctival Autograft Technique: Here, a large excision of the pterygium is performed, and a large graft is placed over it. The surgeon takes an autograft (graft obtained from the same individual) of the conjunctiva and places it over the exposed area following the pterygium removal. This technique has less frequency in causing a recurrence.
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Amniotic Membrane Grafting: An amniotic membrane is obtained from the placenta that develops during pregnancy. It can be used as a graft which is placed over the exposed area of the eye after surgery. A fibrin glue can be used to attach the membrane to the underlying tissues. This technique also prevents recurrence.
For the prevention of recurrences and complete healing of the eyes, a few adjunctive therapies are helpful. They include using Mitomycin C (a chemotherapeutic agent) or MMC, which can be used directly on the eyes after the surgical excision or postoperatively as eye drops. The doctor covers the eye with an eyepatch, and the patient is advised not to touch or rub the operated eye. Complete recovery occurs in a few weeks to months depending on the patient’s condition. The surgical removal of the pterygium, placing a graft over it, and using eye drops helps to provide complete healing and has reduced the recurrence rate.
What Are the Complications After Pterygium Surgery?
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The most common complication is the regrowth of pterygium, which can be prevented by placing a graft.
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Graft edema (swelling of the graft tissue).
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Graft necrosis (death of the graft tissue).
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Scar formation at the cornea.
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Infection.
Conclusion
Pterygium is an overgrowth that occurs in the eye and causes irritation and discomfort. The surgical treatment is only indicated under specific circumstances with severe irritation and growth above three millimeters. The surgical procedure is minimally invasive, causing less discomfort postoperatively, but the recurrence rate is one of the important factors to consider. The use of grafts and MMC eyedrops has reduced the recurrence rate considerably. A regular follow-up with the doctor to check the treatment progress is done to obtain a successful recovery.