Merck Manual

Please confirm that you are a health care professional

honeypot link

Pinguecula and Pterygium


Zeba A. Syed

, MD, Wills Eye Hospital

Reviewed/Revised Apr 2023
Topic Resources

Pinguecula and pterygium are benign growths of the conjunctiva that can result from chronic actinic irritation. Both typically appear adjacent to the cornea at the 3-o’clock position, the 9-o’clock position, or both.

A pinguecula is a raised yellowish white mass within the bulbar conjunctiva, adjacent to the cornea. It does not tend to grow onto the cornea. However, it may cause cosmetic blemish or irritation if elevated due to inflammation and, although rarely necessary, can easily be removed and will typically not recur.

A pterygium is a fleshy triangular growth of bulbar conjunctiva, occurring only at the 3 and 9 o'clock meridians of either eye, usually not simultaneously. The pterygium may spread across and distort the cornea, induce astigmatism, and change the refractive power of the eye. Symptoms may include decreased vision and foreign body sensation. It is more common in sunny, hot, dry climates.

To relieve symptoms caused by a pterygium, artificial tears or a short period of treatment with corticosteroid drops or ointments may be prescribed. Growth of the pterygium may be slowed by the use of a hat that shields the eye from ultraviolet (UV) sunlight and UV block in glasses and sunglasses. Removal is often indicated for documented growth, cosmesis, to reduce irritation, and to improve or preserve vision. Antimetabolites such as mitomycin and 5-fluorouracil (5-FU) have been used effectively—intraoperatively and postoperatively—to decrease recurrence rates, but they have a high complication rate, including scleral and corneal melting. Subconjunctival injections of anti-VEGF (bevacizumab) beneath a pterygium may be useful to prevent progression and improve outcomes when used with pterygium excision plus graft, and for recurrent pterygium. The technique with the best results to prevent recurrence is surgical removal of the pterygium followed by conjunctival autograft.

Pinguecula and pterygium

Pinguecula and pterygium are conjunctival growths that may result from chronic actinic irritation. Pinguecula (left) is accumulation of conjunctival tissue at the nasal or temporal junction of the sclera and cornea. Pterygium (right) is conjunctival tissue that becomes vascularized, invades the cornea, and may decrease vision due to obstruction or induced astigmatism.

Pinguecula and pterygium

Drugs Mentioned In This Article

Drug Name Select Trade
Advanced Eye Relief, Akwa Tears, Akwa Tears Renewed, Alcon Tears, Artificial Tears, Bion Tears, Blink Tears, Clear eyes, Clear eyes Advance Dry and Itchy Relief, Clear eyes Outdoor Dry Eye Protection, Eye Lubricant , FreshKote, Gen Teal Moderate to Severe, GenTeal , GenTeal Mild, GenTeal Moderate, GenTeal PF, GenTeal Severe, GenTeal Tears Mild, GenTeal Tears Severe Dry Eye, Gonak, Goniosoft, Hypo Tears , Isopto Tears, LiquiTears, LubriFresh P.M., Moisture Eyes, Moisture Eyes Preservative Free, Murine, Natural Balance Tears, Nature's Tears, Opti-Free, Puralube Tears, Refresh, Refresh Celluvisc, Refresh Endura, Refresh Lacri-Lube, Refresh Liquigel, Soothe Lubricant Dry Eye Therapy, Systane, Systane Balance, Systane Complete, Systane Ultra, Teargen, Tears Naturale Forte, Tears Naturale Free, Tears Naturale II, Tears Renewed , TheraTears, Visine Dry Eye Relief, Visine Maximum Redness Relief, Visine Pure Tears, Visine Tears, Visine Tired Eye Relief, Viva
JELMYTO, Mitosol, Mutamycin
Adrucil, Carac, Efudex, Fluoroplex, Tolak
Alymsys, Avastin, MVASI, Zirabev
NOTE: This is the Professional Version. CONSUMERS: View Consumer Version
quiz link

Test your knowledge

Take a Quiz!