Pterygium/Pinguecula
Pterygium and pinguecula are eye conditions characterized by growths on the conjunctiva, the membrane covering the eye. Pingueculae are yellowish-white deposits that form due to the accumulation of dead and damaged conjunctival cells, often exacerbated by ultraviolet radiation and environmental factors. In contrast, a pterygium is a non-cancerous growth that occurs when the conjunctival cells proliferate in response to repeated damage, potentially encroaching on the cornea. These conditions are more prevalent in individuals over 40, particularly those living in sunny, dry, or dusty environments, such as fishermen, surfers, and farmers. Symptoms can vary, with many people experiencing no discomfort, while others may seek treatment for cosmetic reasons or inflammation (pingueculitis).
Treatment options typically include lubricating eye drops for mild symptoms, while surgical intervention may be necessary for larger pterygia that affect vision. However, surgical excision can lead to a high rate of recurrence, prompting the use of additional therapies to minimize this risk. Understanding these conditions can help individuals take proactive measures to protect their eye health, particularly in high-risk environments.
Subject Terms
Pterygium/Pinguecula
Disease/Disorder
Also known as: Surfer’s eye
Anatomy or system affected: Eyes
Definition: A thickening of conjunctiva of the eye that grows onto the cornea (pterygium) or degeneration of a portion of the conjunctiva (pinguecula).
Key terms:
conjunctiva: the clear, moist membrane that coats the inner surfaces of the eyelids and the outer surface of the eye
cornea: the clear front window of the eye that transmits light into the eye
sclera: the tough white outer covering over the eyeball that extends over most of its surface
Causes and Symptoms
When ultraviolet radiation from sunlight irradiates the conjunctiva, it can damage and kill conjunctival cells. Repeated sunlight exposure can sometimes produce small accumulations of dead and damaged conjunctival cells combined with degraded matrices that appear as yellowish-white deposits that sometimes calcify. Such a deposit is called a pinguecula (plural, pingueculae). Alternatively, in response to continued conjunctival cell death, the cells divide to replace the dead cells. Repeated damage to the conjunctiva can hyperactivate this healing response and a nontumorous growth of conjunctival cells, called a pterygium, thickens the conjunctiva and eventually grows over the cornea. In some cases pingueculae precede pterygia.
Pterygium and pinguecula occur with increasing frequency in climates that approach the equator. Those who live in dry, dusty environments, fishermen, surfers, and farmers experience increased rates of pterygium and pinguecula. Some studies have found that smoking increases the rates of pterygium and alcohol consumption increases the rates of pinguecula. Although pterygium and pinguecula can arise in anyone, they are rarely seen in those younger than 20 years old. People over 40 show the highest prevalence of pterygium and pinguecula and those between the ages of 20–40 have the highest incidence.
Treatment and Therapy
In most cases, pterygium and pinguecula do not cause any symptoms and require no treatment. Pingueculae tend to grow slowly and may, in some cases, appear unsightly, in which cases they can be surgically removed. Pingueculae can also cause some eye discomfort and in such cases over-the-counter artificial tear products (e.g., Refresh Tears, GenTeal) or lubricating ointments (e.g., Refresh P.M., Hypo Tears) can provide relief. Infrequently, pingueculae can become inflamed (pingueculitis), which are effectively treated with prednisone eye drops (Pred Fotre).
Pterygium often requires no treatment unless it overgrows the cornea and deforms or scars it. In such cases, the pterygium significantly affects patient’s sight and surgical extirpation can potentially restore normal sight to the eye. Unfortunately, simple excision has a high rate regrowth of the pterygium (24–89 percent). To prevent regrowth, radiation therapy and chemical agents such as mitomycin C, 5-fluorouracil, and thiotepa have been applied to the eye prior to surgery. Secondly, the sclera is covered with either amniotic membrane or a small piece of conjunctiva cut from the patient’s own eye (free conjuntival autograph). These modifications to pterygium surgery have greatly reduced the rate of recurrence of pterygium.
Bibliography
Hirst, Lawrence W. “Recurrence and Complications after 1000 Surgeries Using Pterygium Extended Removal Followed by Extended Conjunctival Transplant.” Ophthalmology 119, no. 11 (November, 2012): 2205–2210.
Kee, Kenneth. A Simple Guide to Conjunctivitis and Other Eye Diseases. Seattle, WA: Amazon Digital Services, 2012.
Lusby, Franklin W. “Pinguecula.” MedlinePlus. US Natl. Lib. of Medicine, Natl. Inst. of Health, 20 Nov. 2012. Web. 18 Mar. 2015.
Lusby, Franklin W. “Pterygium.” MedlinePlus. US Natl. Lib. of Medicine, Natl. Inst. of Health, 20 Nov. 2012. Web. 18 Mar. 2015.
“What Is a Pinguecula and a Pterygium?” Eye Smart. Amer. Acad. of Ophthalmology, 2015. Web. 18 Mar. 2015.