What Is Pterygium?

Pterygium is a common and frequently-occurring disease in ophthalmology. Traditional Chinese medicine calls it "plum meat", commonly known as "fish meat". It is generally considered to be a chronic inflammatory lesion caused by external stimuli. It suffers from one or both eyes, and is named because it resembles an insect's wings. It is a kind of neoplastic tissue on the conjunctiva and cornea of the palpebral cleft, which gradually increases after invading the cornea, and can even cover the pupil area and seriously affect vision. It is the degeneration, hypertrophy, and hyperplasia of the bulbar conjunctiva and subconjunctival tissue that develops into the cornea and is triangular. More common in outdoor workers, fishermen and farmers have the highest incidence, which may be related to long-term chronic stimuli such as wind, dust, sunlight, and smoke.

Basic Information

nickname

Meaty eyes

English name

pterygium

Visiting department

Ophthalmology

Multiple groups

Outdoor laborer

Common causes

May be related to long-term chronic stimuli such as wind, dust, sunlight, smoke, etc.

Common symptoms

Impaired vision caused by pterygium intrusion into the pupil area

Causes of pterygium

Physical factors

Consider heredity, nutritional deficiencies, insufficient tear secretion, allergic reactions, and anatomical factors. Some people think that due to abnormal tear film, insufficient secretion of tear fluid, corneal and conjunctival dryness caused local tissue hyperplasia. Pinkerton et al. Pointed out that the occurrence of pterygium meat is related to immunology. The antigenic substance may be pollen or dust particles containing antigenic substances. IgE and IgG were found in pterygium meat tissue by immunofluorescence, and the existence of IgE may be related to type I Allergic reactions. Some people think that it is caused by the abnormal development of elastic fibers in the conjunctival tissue. Histological examination revealed plasma cell and lymphocyte infiltration in the pterygium matrix.

It has been mentioned that the medial rectus muscle has strong control ligament development. When subjected to some external stimuli, its connective tissue can proliferate excessively and cause the disease; Wong (1978) proposed that the disease is caused by the conjunctival blood vessels and the corneal Bowman membrane. A non-infectious inflammation, where the self-initiated process of inflammation leads to the degradation of proteins into a mixture of amino acids, which contains a type of "pterygium angiogenic factor" that has the ability to promote conjunctival blood vessels to crawl over the cornea.

2. Environmental factors

External stimuli such as the eyes have been excessively stimulated by wind, sand, dust, heat, sunlight, pollen, etc., especially long-term outdoor workers such as fishermen, farmers, seafarers, gravel workers, etc., make the limbal conjunctiva under the influence of the above-mentioned stimuli. Vascular or conjunctival epithelial tissues undergo non-infectious chronic inflammation, tissue proliferation, fibroblast proliferation, lymphocyte and plasma cell infiltration, which are a series of processes of pterygium formation.

Clinical manifestations of pterygium

1. Most of them have no conscious symptoms or only mild discomfort. When the palate extends to the cornea, astigmatism occurs due to the drag; or the palate extends into the corneal surface and grows to cover the sleeping holes, which causes visual disturbance. Very serious cases can occur. Affects eye movements to varying degrees.

2. Unilateral carcass is more common on the nasal side, and bilateral ones are on the nasal and Yan sides of the cornea, respectively. At the initial stage, the corneal limbus was gray and cloudy, and the conjunctiva was congested and hypertrophic. Later it developed into a triangular vascular tissue. It can be divided into three parts: head, neck, and body. The tip is the head, the limbus is the neck, and the bulbar conjunctiva is the body.

3. Carcass can be divided into progressive or stationary phase according to the progress of its lesions. The head of the carcass was raised, and the nearby cornea was cloudy, with cell infiltration in the anterior elastic layer and the superficial stromal layer. The neck is wide, the body is thick, the surface is uneven, and there are thick and dilated blood vessels. The resting stage of the carcass is flat, the cornea is infiltrated and absorbed, the body is not congested or slightly congested, the surface is smooth, and the lesion is still.

Diagnosis and differential diagnosis of pterygium

It is generally not difficult, but it needs to be distinguished from pseudopterygium and blepharoplasma.

True pterygium is the result of chronic inflammation of the conjunctiva and subconjunctival tissue, which develops into the cornea.

Pseudopterygium is generally an acute injury to the limbal region of the cornea. Adhesion between the bulbar conjunctiva and the corneal lesion occurs near it, forming a conjunctival bridge.

Pseudopterygium grows at any part of the corneal edge, and is generally small and has no development trend. It is caused by adhesion between the bulbar conjunctiva and corneal epithelium. It can be seen clinically that a cord or triangular conjunctival fold is fixed in the cornea turbidity, which mostly occurs after corneal ulcer, burn or chemical corrosion injury. Because the conjunctiva only adheres to the cornea at the head, a probe can be passed under the neck smoothly, instead of full adhesion to the surrounding tissue like a true pterygium.

The blepharoplasma is a degeneration lesion of the bulbar conjunctiva caused by sunlight and ultraviolet rays. It is located in the bulbar conjunctiva of the palpebral fissure. There are yellow and white amorphous bulges on the inside and outside of the limbus. It can gradually expand after a certain period of time without invading the cornea. Affects aesthetics, so treatment is usually not required.

Pterygium Treatment

Try to avoid external irritation and actively treat chronic eye inflammation.

Antibiotic

Use antibiotic eye drops to control conjunctival inflammation and reduce congestion. In severe congestion, corticosteroid eye drops can be added. To reduce external irritation, wear appropriate color changing lenses.

2. Other

Small, stationary pterygium does not require treatment. If the flesh is progressive or is close to the pupil area, affecting vision or limited eye movement, it is feasible to be removed. For patients who are unwilling to undergo surgery, 0.3ml of Zanthomycin solution 2000-3000U / ml can be injected into the neck and body of pterygium under topical anesthesia, once a week, 3 to 6 times as a course of treatment. In order to reduce the local response, 0.3ml of prednisolone and tetracycline cortisone eye ointment can be injected under the contralateral bulbar conjunctiva.

3. Cryotherapy

Use a frozen head at 40 ° C to contact the head and neck of the carcass, destroying its new blood vessels and shrinking it. For smaller and thinner pterygium.

4. Surgery

(1) Indications The pterygium is progressive, hypertrophic, and hyperemic; The pterygium has invaded the near pupil area and affected vision.

The surgical treatment of pterygium should meet 3 main objectives: the patella should be safely removed; achieve good optical effects; avoid recurrence. Therefore, special care must be taken when choosing a surgical method.

(2) Surgical methods Pterygium simplex excision is suitable for those who invade the cornea more, and are those who have progressive palate or close to the edge of the pupil to threaten the visual function of the eye, or have an effect on cataracts or corneal transplant incisions After surgery, it may stimulate the development of pterygium, or it may hinder the patient's aesthetics. This surgical method is also relatively simple and relatively short, but it is easy to relapse after surgery. Pterygium resection combined with free conjunctival flap transplantation is suitable for those with larger pterygium, hyperemia, hypertrophy, and faster growth, or those with more conjunctival loss during pterygium resection. The operation of this surgical method is relatively complicated and difficult, and the conjunctival flap used for transplantation must be prevented from being upside down, but the surgical effect is better and the postoperative recurrence rate is relatively low. Pterygium resection and pedicled conjunctival flap transplantation This surgical method is also suitable for those who have thicker and thicker congestion and grow faster. Due to the elasticity and good compliance of the conjunctiva, this feature can be used to separate the bulbar conjunctiva adjacent to the pterygium resection area, and then perform appropriate loosening and shearing for displacement transplantation to repair the exposed scleral area. In this method, the conjunctival flap is not reversed, and the blood supply is good, and the transplanted conjunctiva grows faster and heals. The disadvantage is that there may be a certain tension when the conjunctiva is pulled and displaced, so the wound should be well aligned to prevent the conjunctival wound from cracking.

References

1. Chinese Ophthalmology; People's Medical Publishing House; 2005

2.NigerJMed.2011Jan-Mar; 20 (1): 7-14.Pterygium: Areviewofclinicalfeaturesandsurgicaltreatment.

3.AnnAfrMed. 2011 Jul-Sep; 10 (3): 197-203. Treatment ofpterygium.