What are the symptoms of pterygium?

The common symptoms of pterygium include congestion and hypertrophy of the bulbar conjunctiva in the palpebral fissure. As the disease progresses, there will also be grayish-white gelatinous bulges on the head, vascular congestion and tissue hypertrophy in the neck. Patients should pay attention to these symptoms to make judgments and treatments.

1. Initial development of pterygium

Conjunctival stage pterygium: The bulbar conjunctiva at the palpebral fissure becomes congested and thickened, gradually extending to the surface of the cornea to form a triangular pterygium with vascular tissue, which resembles the wings of an insect, hence the name pterygium. It mostly occurs on the nasal side and less frequently on the temporal side. When extending toward the cornea, it can invade the anterior elastic layer and superficial stroma.

2. Pre-corneal pterygium: A triangular congested fold formed by the thickened conjunctiva, with the head spanning the corneal margin and the fan-shaped base, extending beyond the semilunar fold to both sides of the lacrimal caruncle, in the anterior area of ​​the corneal margin, which is the neck of the pterygium. The head of the pterygium bulges on the corneal margin and extends about 2mm beyond the corneal margin into the cornea, with tiny blood vessels on the surface. At the end of the head, there is a grayish white bubble-like island composed of accumulated particles invading the superficial layer of the cornea, which is the Fuchs island. The cornea around the island and head appears cloudy and difficult to identify with the naked eye. There are also grayish-white stripes composed of particles near the body, and dilated blood vessels are distributed along the corneal margin. The head and neck are adherent to the corneosclera in the area of ​​infiltration and hyperemia. Fluorescein staining shows epithelial punctate desquamation.

3. Progress of pterygium

The head is a grayish-white gelatinous protrusion with a vertical serrated edge at the end. The neck is filled with blood vessels and the tissue is thickened. The surface of the pterygium head is slightly raised, with scattered calcification points nearby. The progressing edge can pass through the center of the pupil and reach deep into the anterior elastic layer of the cornea. Its epithelium is raised and obviously turbid.

Due to the pulling effect of pterygium on the cornea, the curvature of the cornea may change and cause astigmatism. Habsen et al. examined 39 eyes and found that pterygium eyes showed regular astigmatism, with the degree of astigmatism reaching 5D, but most of them did not have a decreased visual acuity. Lin et al. measured the contrast sensitivity of the naked eye and found that each spatial frequency was significantly reduced. At the same time, it was found that the glare phenomenon was significantly increased compared with normal eyes.

The pterygium can be stable for a long time, with no obvious congestion, tissue hypertrophy, a slightly raised head, and the cornea in front is grayish white infiltrated. The pterygium continues to advance toward the center of the cornea, which is called the progressive stage. Most patients have no subjective symptoms, but when the pterygium expands toward the center of the cornea, it can cause astigmatism. If it covers the pupil, it will seriously affect vision. The thickened and contracted pterygium can restrict eye movement.