Pterygium: Causes, Symptoms, Diagnosis, and Treatment

A pterygium is a fleshy, raised growth on the conjunctiva of your eye. The transparent membrane that covers the white of your eye is called the conjunctiva. The cornea, the clear portion of the eye, is often where the conjunctiva terminates. Your eyelids' inside are lined with it as well.

Pterygium is derived from the Greek terms pteryx, which means "wing," and pterygion, which means "fin." A pterygium is a thickening of conjunctiva tissue that resembles wings or is shaped like a triangle. The corner of your eye closest to your nose normally sprouts more frequently than the other. It expands outward, occasionally touching the cornea of your eye.

One or both of your eyes may be affected by pterygium, but generally not simultaneously. when it simultaneously affects both eyes.

Read this blog further to get a quick overview of this important topic for OPTHALMOLOGY  to ace your NEET PG exam preparation.

Causes Of Pterygium

It is unknown what specifically causes pterygium. The development of these growths can be explained, in part, by excessive ultraviolet (UV) light exposure. People who reside in warm climates and spend a lot of time outdoors in hot or windy weather are more likely to experience it. An increased chance of getting this illness exists in those whose eyes are regularly exposed to specific components. They consist of the following:

• Pollen
• Sand
• Smoke
• Wind

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Symptoms Of Pterygium

In certain cases, pterygium develops without any prior symptoms. When symptoms do appear, they can be moderate or quite serious.

Early warning signs and symptoms consist of:

• An eye growth that is pink and somewhat elevated.
• Eyes that are puffy, itchy, or red.
• Eyes that are dry, scratchy, or burning.
• Having the impression that sand or grit is in your eyes.
• Gloomy eyes.

Late warning signs and symptoms include:

• The lesion has grown larger and expanded further.
• Your eye will have an unpleasant appearance as a result of the lesion's size.
• Double vision or blurry eyesight (if pterygium develops on the cornea).

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Pathology Of Pterygium

Pterygium in the conjunctiva is characterized by fibrovascular growth, actinic elastosis, and elastotic degradation of collagen. The head of the pterygium joins to the main body of the pterygium by the neck. The Stocker's line, a line of iron deposition next to the pterygium's head, is occasionally visible. The placement of the line can reveal information about the growth trend.

The prevalence of pterygia on the nasal side may be due to peripheral light focusing, in which sunlight passes laterally through the cornea before being refracted and focusing on the limbic region.

From the lateral side of the eye, sunlight enters unobstructed and passes through the cornea before focusing on the medial limbus. However, the shadow cast by the nose on the medial (contralateral) side medially lessens the amount of sunlight that is concentrated on the lateral/temporal limbus.

Vimentin expression, which denotes cellular migration by the keratoblasts embryological development the cells that give rise to the layers of the cornea and other studies have also suggested a genetic susceptibility. The congenital pterygium a pterygium that develops in infants supports this assertion. Due to the tumor suppressor gene being deficient, these cells also show elevated P53 expression.

Because the limbal epithelium actually initiates the cellular origin of the pterygium, these signs provide the appearance of a migrating limbus.

A number of segments make up the pterygium:

• The pterygium head is surrounded by tiny gray spots called Fuchs' Patches.
• (A line of iron deposits that is brown in color) Stocker's Line
• Hood, the fibrous, nonvascular part of the pterygium
• Head (pterygium's characteristically elevated, highly vascular apex)
• the body's raised, fleshy region that is crowded with tortuous vessels
• The superior edge (also known as the upper edge of the triangular or wing-shaped section of the pterygium)
• The lower edge of the triangular or wing-shaped part of the pterygium is called the inferior edge.

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Diagnosis Of Pterygium

Pterygium can be identified with a slit lamp by your eye doctor. When you utilize a slip lamp, a narrow (or "slit") line of brilliant light is focused on your eye. It facilitates your doctor's examination of your eye's exterior and interior. One typical component of an eye exam is a slit lamp examination.

Your doctor might conduct the following additional eye exams:

Checks your visual acuity by having you read letters or symbols on a chart from a distance of 20 feet.

Treatment Of Pterygium

Unless a pterygium expands to the point that it impairs vision, surgery is often not necessary. Artificial tears can be used to treat some of the symptoms, such as irritation. For uncontrollable symptoms, surgery can potentially be a possibility.

Surgery

Surgery to remove pterygia

According to a Cochrane analysis, compared to amniotic membrane transplant, conjunctival autograft surgery had a lower 6-month risk of the pterygium returning. To identify which form of surgery improved eyesight or quality of life, more research is required. The added usage of mitomycin C has unknown effects. In an effort to lower the chance of recurrence, radiotherapy has also been applied.

Auto-grafting

Pterygium excision with the surgical technique known as conjunctival auto-grafting is both efficient and secure.

Tenon layer tissue, which covers the sclera, is also removed when the pterygium is removed. By surgically removing conjunctival tissue from a healthy conjunctiva area, autografting replaces the exposed sclera with conjunctival tissue. Then, using sutures or tissue glue, the "self-tissue" is transferred to the exposed sclera.

Transplanting amniotic membranes

A safe and efficient method of removing pterygia is amniotic membrane transplantation. For comprehensive pterygium excision, transplanting amniotic membranes provides a useful alternative to transplanting conjunctival autografts. Amniotic membrane transplantation is a technique that involves using tissue taken from the human placenta's innermost layer to repair and replace damaged mucosal surfaces, including the effective rebuilding of the ocular surface. It has a strong anti-adhesive action and has been utilized as a surgical material since the 1940s.

An amniotic transplant can be used to speed up epithelialization and has anti-inflammatory and surface rejuvenating capabilities. The use of sutures or glue adhesive is another option for securing transplanted amniotic membranes to the sclera. The recurrence rate offered by the amniotic membrane alone is not satisfactory.

Also Read: Subconjunctival Haemorrhage: Causes, Symptoms, Risk Factors, Diagnosis, Treatment, Prevention and Complications

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