Glossary of Terms
Phototherapeutic keratectomy (PTK) can treat superficial corneal dystrophies, corneal scars, and certain corneal infections. Only a short time ago, people with these disorders would most likely have needed a corneal transplant.
- Synonyms: PTK
At this advanced stage, the signals sent by the retina in the third stage trigger the growth of new blood vessels. These new blood vessels are fragile and break easily. They grow along the retina and along the surface of the clear, vitreous gel that fills the inside of the eye. On their own, these blood vessels do not cause symptoms or vision loss. But if they break and leak blood, they can cause severe vision loss and even blindness.
A pterygium is a pinkish, triangular-shaped growth of tissue on the cornea. Pterygia are more common in sunny climates and in people aged 20 to 40. Some pterygia grow slowly throughout a person's life, while others stop growing after a certain point. A pterygium rarely grows so large that it begins to cover the pupil of the eye.