What are the physical characteristics of a pterygium (pterygium, also known as surfer's eye)?

From the Guidelines

A pterygium is characterized as a triangular, wing-shaped growth of fibrovascular tissue extending from the conjunctiva onto the cornea, typically appearing as a pinkish, fleshy tissue with a head, neck, and body, and often containing visible blood vessels. The physical characteristics of a pterygium include its location, usually originating from the nasal side of the eye and growing toward the center, although it can also develop on the temporal side. Key features of a pterygium include:

• A triangular or wing-shaped appearance
• A pinkish, fleshy color
• Presence of visible blood vessels
• A head, neck, and body structure, with the head being the advancing portion on the cornea, the neck at the limbus where the cornea meets the sclera, and the body on the conjunctiva
• Variability in size, ranging from small to large enough to extend across the pupil and potentially affect vision
• Possible appearance of being dry and inflamed, with a yellowish deposit of fat or protein. According to the study on corneal edema and opacification preferred practice pattern 1, sun exposure, such as that experienced by individuals working outdoors (e.g., farming, construction) or engaging in leisure activities (e.g., boating, golfing), may contribute to the development of pterygium, highlighting the importance of ultraviolet light exposure in the formation of this condition.

From the Research

Physical Characteristics of Pterygium

• Pterygium is a degenerative condition characterized by fibrovascular outgrowth of conjunctiva over the cornea 2
• It represents a triangular conjunctivo-epithelial overgrowth, proliferating from the bulbar conjunctiva and covering the cornea 3
• Pterygium is composed of degenerated basophilic subepithelial tissue 4
• The lesion has a conjunctivo-epithelial structure, significantly different from the structure from which it developed 3
• The covering epithelium of the pterygium can appear pleomorphic, with dysplastic aspects, suggesting significant alteration of cell proliferation and differentiation 3
• Goblet cells are often present in the surface epithelium of the pterygium, synthesizing and accumulating PAS-positive mucines rich in glycosaminoglycans 3
• A highly developed vascular neoformation network, consisting of arterioles, venules, and a large number of capillaries, can be found in the connective tissue of the pterygium 3

Histological Features

• Histological studies of pterygium have shown the presence of a conjunctivo-epithelial structure, with a covering epithelium that can be similar to that of the bulbar conjunctival mucosa 3
• Immunohistochemistry has highlighted the presence of T-lymphocytes, B-lymphocytes, and macrophage-type cells in the connective tissue of the pterygium 3
• The immune cell infiltrate in pterygium is diffuse, with a greater abundance in areas with erosion of the covering epithelium 3

Clinical Presentation

• Pterygium can cause significant vision loss, particularly if it affects the visual axis 2, 3
• The lesion can cause dry eye manifestations, such as burning, itching, and/or tearing 2
• As the lesion grows toward the optical zone, visual acuity can become compromised, requiring surgical treatment 2