A pterygium is an elevated, superficial, external mass that usually forms over the conjunctiva and extents onto the corneal surface. The growth is generally benign and it commonly looks like a triangular overgrowth of the cornea of the eye. This paper shows more information about pterygium and a TCM approach to treating it.
According to Fargo, 2008, chap 4.9: “Pterygium is a benign thickening of the outer coating (conjunctiva) of the eye that grows into the cornea.” As a pterygium grows, it may become red and irritated. It can vary from small, atrophic quiescent lesions to large, aggressive, rapidly growing fibrovascular lesions that can distort the cornea.
UV radiation (usually from sunlight) is the most common cause of pterygium. This explains why pterygium occurs with increasing frequency in climates approaching the equator. Other causes include continuous exposure to dry, dusty environments. People who spend significant time doing water sports (i.e. surfing or fishing) are particularly susceptible to pterygium because of the intense exposure to UV that occurs in these environments.
When the eye is continuously assaulted by UV rays, the conjunctiva may thicken in a process similar to callus formation on the skin. The sensitive structures of the outer eye often cannot comfortably tolerate this degenerative process, and irritation, redness, foreign body sensation, and ocular fatigue can result.
In most cases, routine ocular evaluation reveals pterigyum in asymptomatic individuals or patients who present with cosmetic concern about a tissue "growing over the eye." In some instances, the vascularized pterigyum may become red and inflamed, motivating the patient to seek immediate care. There are irritation symptoms in severe cases, such as itching or dry eyes, redness, or affecting eye sight. It can also lead to other eye diseases, so early prevention is crucial.