- Home
- Knowledge centre
- Eye glossary A–Z
- Pterygium: What It Is, Causes, Symptoms and Treatment
Pterygium: What It Is, Causes, Symptoms and Treatment
Medically reviewed by {{surgeon}}, {{surgeon's title and specialty}}, on {{review date}}. Last updated {{date}}.
Pterygium (noun, pronounced ter-IJ-ee-um; plural pterygia): a pterygium is a fleshy, wing-shaped growth of tissue that starts on the conjunctiva (the clear membrane over the white of the eye) and spreads across the edge of the cornea, usually from the side nearest the nose. It is not cancer, and it is caused mainly by long-term exposure to sunlight (ultraviolet light), wind and dust. Many pterygia cause only mild irritation, but a growing one can distort vision and, if it threatens sight, is removed with surgery, which at Laser Istanbul Clinic is led by Doç. Dr. Muhammet Derda Özer, our cornea specialist.
Pterygium: key facts
- What it is
- A benign, wing-shaped growth of conjunctival tissue with blood vessels that grows onto the cornea
- Name
- From the Greek pterygos, "wing" (EyeWiki, AAO)
- Where it starts
- At the limbus, the border between the white of the eye and the cornea; more often on the nasal side than the temporal side
- Main cause
- Ultraviolet (UV) light exposure, with wind and dust as contributing factors
- How common
- A 2013 meta-analysis of 20 population studies (900,545 people) found a pooled prevalence of 10.2% worldwide, higher closer to the equator and in older people
- Usual symptoms
- None at first; later irritation, redness, a gritty feeling, watering, blur from astigmatism, or a cosmetic concern
- Can drops cure it?
- No. Drops ease irritation and redness; only surgery removes the tissue
- Surgery
- Removal with a conjunctival autograft is the standard operation; recurrence is about 5–10% with a graft, against about 80% when the growth is only cut away
- Specialist
- Ophthalmologist with cornea and ocular-surface expertise; at Laser Istanbul Clinic, Doç. Dr. Muhammet Derda Özer
What is a pterygium in the eye?
A pterygium of the eye is a triangular, fleshy growth that begins in the conjunctiva at the limbus and creeps onto the clear cornea. The American Academy of Ophthalmology (AAO) describes it as fleshy tissue with blood vessels that can develop from a pinguecula and can expand to cover part of the cornea. Under the microscope, the tissue is degenerated and full of blood vessels, and as it advances it destroys the cornea's thin front support layer, Bowman's layer (EyeWiki).
Most people who have a pterygium notice it first in the mirror, as a pink or red triangle on the white of the eye pointing toward the pupil. It can affect one eye or both, and it is more often seen in one eye only. When people search for "pterygium eyes", what they are looking at is almost always this: a sun-related growth on the surface of the eye, not an infection and not a tumour.
Pterygium causes: why does it grow?
The main pterygium cause is ultraviolet (UV) light. EyeWiki, the AAO's clinical encyclopedia, names UV exposure as the primary risk factor. The AAO adds that both pterygium and pinguecula result from a combination of sunlight, wind and dust. The causes and the groups most at risk fit together:
| Risk factor | What the evidence says |
|---|---|
| Sunlight (UV) | The leading cause; the growth is most common in hot, sunny regions near the equator |
| Latitude | A 2013 meta-analysis in BMJ Open found higher prevalence at lower latitudes (closer to the equator) |
| Outdoor activity or work | In the same analysis, the pooled odds ratio for outdoor activity was 1.76 |
| Male sex | The same analysis gave an odds ratio of 2.32 for men; EyeWiki suggests this may reflect greater UV exposure |
| Age | Prevalence rises with age, consistent with UV exposure building up over the years |
| Wind and dust | Named by the AAO as contributing causes alongside sunlight |
In practical terms, farmers, builders, fishermen, sailors, drivers and people who live in hot, dry, dusty places such as the Gulf are the classic patients. A pterygium is not an infection and is not contagious.
Pterygium symptoms: what does it feel and look like?
Many pterygia produce no symptoms at all. When symptoms do appear, the most common ones are:
| Symptom | Why it happens |
|---|---|
| A visible pink or red, wing-shaped growth on the white of the eye | The tissue is full of blood vessels |
| Redness and swelling of the white of the eye | Surface inflammation, often worse in wind, sun or dry air |
| Dryness, itching, burning or a gritty, "something in my eye" feeling | The raised tissue irritates the surface of the eye |
| Watering | Irritation of the surface |
| Blurred or changing vision | The growth changes the shape of the cornea (induced astigmatism) or grows across the pupil area |
| Concern about appearance | A red growth is visible, and some people want it removed for cosmetic reasons |
| Limited eye movement (rare, advanced) | EyeWiki lists restricted eye movement among the reasons for surgery |
The key point for vision: a pterygium that stays at the edge of the cornea may not affect sight. Once it grows toward the centre, it can cause astigmatism and eventually cover the visual axis, so any growth that is getting bigger deserves a check-up.
Pterygium vs pinguecula: what is the difference?
The difference between a pinguecula and a pterygium is whether the growth reaches the cornea. EyeWiki defines a pinguecula as a raised, yellow-white, non-malignant spot on the conjunctiva that does not involve the cornea. A pterygium, by contrast, crosses the limbus and extends onto the cornea. If you are searching "pinguecula vs pterygium", this is the test the doctor applies.
| Pinguecula | Pterygium | |
|---|---|---|
| Appearance | Yellowish, raised bump or patch on the white of the eye, usually near the nose | Pink or red, fleshy, wing-shaped growth with visible blood vessels |
| Reaches the cornea? | No | Yes: it grows across the edge of the cornea |
| Affects vision? | Usually not | Can, through astigmatism or by covering the pupil area |
| Usual cause | Sunlight, wind and dust | The same causes |
| Usual treatment | Lubricating drops; surgery is typically unnecessary (AAO) | Lubricating drops for irritation; surgery if it threatens vision, keeps irritating, grows or restricts eye movement |
| Link between them | EyeWiki notes that inflamed pingueculae with a poorly lubricated surface may be a subgroup more likely to progress to pterygium | A pterygium can develop from a pinguecula (AAO) |
Two other things can look similar and should be ruled out by a doctor. A pseudopterygium is a scar-like band that attaches to the cornea after an injury or inflammation, and ocular surface squamous neoplasia (OSSN) is a rare surface tumour. Our sibling page explains the yellow spot in full.
How is a pterygium diagnosed?
A pterygium is diagnosed by looking at it: an eye doctor examines the eye with a slit lamp, a microscope with a bright, thin beam of light that shows the growth and how far it has crossed onto the cornea. Your surgeon will usually also:
- check your vision and glasses prescription, because a pterygium can change the shape of the cornea;
- map the cornea with corneal topography to measure any astigmatism the growth has caused;
- look for features that need a second look. EyeWiki lists white patches (leukoplakia), pigmentation, irregular feeder vessels, an unusual raised surface and rapid growth as signs that should raise suspicion of ocular surface squamous neoplasia. For this reason, histopathology (laboratory examination) is routinely performed on tissue removed at surgery.
You can send us your existing eye report and scans before you travel, and your surgeon will review them first.
Is a red eye a pterygium or an infection?
Not every red eye with a growth is a pterygium, and not every red eye in someone with a pterygium is caused by it. A pterygium can look like simple conjunctivitis at first, but there are clear differences:
| Sign | Points to |
|---|---|
| A fleshy, wing-shaped triangle that stays in the same place and slowly grows over months or years | Pterygium |
| Redness in both eyes, sticky or watery discharge, spreading over days | Conjunctivitis (infective or allergic) |
| Pain, strong light sensitivity, a white or grey spot on the cornea, and blurring | Corneal infection or inflammation (keratitis): urgent |
| A deep, aching red eye with light sensitivity and a change in vision | Inflammation inside the eye, for example uveitis: urgent |
A pterygium can become inflamed and red on a windy or sunny day without being infected (the AAO lists redness and swelling among its symptoms). If the redness comes with pain, discharge or falling vision, do not assume it is "just the pterygium". The infections page explains the warning signs of conjunctivitis, keratitis and endophthalmitis, and the uveitis page explains inflammation inside the eye.
Pterygium treatment: from eye drops to removal surgery
Pterygium treatment depends on how much the growth bothers you and whether it threatens your vision. A small pterygium with no symptoms usually needs no treatment, only monitoring and sun protection. Irritation is treated with drops. Surgery is the only way to remove the growth itself.
Pterygium treatment eye drops: which drops are used?
No eye drop can make a pterygium disappear. The drops used are for symptoms, and EyeWiki lists three types of medical management:
| Drop type | Purpose | Notes |
|---|---|---|
| Lubricating drops (artificial tears) | Soothe dryness, grittiness and burning | First choice for mild symptoms; the AAO recommends them for both pterygium and pinguecula |
| Short-course steroid drops | Calm inflammation and redness when the growth is inflamed | Prescription only, short courses and monitored by a doctor; the AAO says steroid drops may be prescribed for redness and swelling |
| Vasoconstrictor (decongestant) drops | Reduce visible redness | Listed by EyeWiki as an option; ask your doctor which one is suitable |
We do not recommend brand names, because the right drop depends on your eye. Do not use steroid drops without a prescription: they can raise eye pressure and hide an infection.
When is pterygium removal needed?
EyeWiki states that surgical excision is indicated if the pterygium:
- causes persistent irritation that does not respond to medical treatment;
- blocks the line of sight or blurs vision through induced astigmatism;
- is increasing in size; or
- restricts the movement of the eye.
Some people also choose surgery for appearance. A small, quiet pterygium can be monitored first, but a growth that is clearly heading toward the pupil is better dealt with before it affects the cornea's shape.
How is a pterygium removed?
Pterygium removal means the surgeon cuts out the growth and then covers the bare area so that it heals without the growth returning. The standard technique, described by EyeWiki as the gold standard, is excision with a conjunctival autograft:
- The eye is numbed with anaesthetic.
- The growth is carefully separated from the cornea and removed.
- A thin piece of healthy conjunctiva from the surface of the same eye is placed over the bare area. The AAO describes this as transplanting "a thin piece of normal tissue" to reduce the chance of recurrence.
- The graft is fixed in place with stitches or with fibrin tissue glue.
- Topical steroid drops are usually given in the early postoperative period, and the eye is checked afterwards to watch for recurrence.
Stitches or glue? The 2016 Cochrane review by Romano and colleagues compared fibrin glue with sutures for fixing the graft in primary pterygium surgery, and its summary states that, in terms of recurrence, conjunctival autograft is currently the best surgical option. Both ways of fixing the graft are used; ask your surgeon which they prefer for your eye.
Does a pterygium come back? Recurrence by technique
Recurrence is the main downside of pterygium surgery. EyeWiki gives these figures:
| Technique | Recurrence |
|---|---|
| Bare sclera (growth cut away and the area left uncovered, or closed directly) | About 80%, which EyeWiki calls unacceptable |
| Conjunctival autograft (standard) | About 5–10% |
| Amniotic membrane graft | Higher than autograft |
| Adjuvant mitomycin C or 5-fluorouracil | About 10% |
| P.E.R.F.E.C.T. technique (extensive removal of Tenon's tissue plus an autograft) | As low as about 1 in 1,000 in the series EyeWiki describes |
EyeWiki also notes that 97% of recurrences occur in the first year, which is why follow-up in that period matters. Mitomycin C and 5-fluorouracil can cause serious complications, including melting of the cornea or sclera (the white wall of the eye), so they are used only in selected cases. Other risks of surgery listed by EyeWiki include corneal scarring, corneal perforation, squint (strabismus) and a non-healing surface of the cornea. Some astigmatism can remain after the growth is removed.
Our approach. Cornea and ocular-surface surgery at Laser Istanbul Clinic is led by Doç. Dr. Muhammet Derda Özer (Doç. means Associate Professor), who also performs corneal transplants and cross-linking. {{Confirmed: pterygium removal with conjunctival autograft is performed by Doç. Dr. Özer}} Surgery takes place in a fully equipped, Ministry of Health–licensed operating theatre in Istanbul. Our care includes the pre-operative examination and scans, surgery by your named surgeon, medication, follow-up checks in Istanbul, a personal interpreter, a coordinator and remote follow-up. Hotel and airport transfers are not included; we arrange them on request at a separate charge, and flights are not included.
Pterygium nail: is it the same thing?
No. A pterygium on the nail (pterygium unguis) is a different condition from the eye's pterygium; it shares only the Greek name for "wing". In the nail, skin of the nail fold or nail bed forms a wing-like extension. Dermatology papers describe two forms:
- Dorsal pterygium unguis appears as a V-shaped extension of the skin at the base of the nail (the proximal nail fold) and is often associated with damage to the nail (traumatic onychodystrophy).
- Pterygium inversum unguis is the opposite problem: the skin under the free edge of the nail (the hyponychium) sticks to the underside of the nail plate, so the groove under the tip of the nail disappears. A review of 19 cases was published in Archives of Dermatology in 1993, and a 2013 case report described a good response to treatment with hydroxypropyl chitosan.
For pterygium nail treatment, see a dermatologist, who can look for the cause and advise on care. Eye surgeons do not treat nail pterygium, and the eye condition described on the rest of this page has nothing to do with the nails.
How can you prevent a pterygium or stop it getting worse?
Prevention comes down to protecting the eye surface. The AAO and EyeWiki recommend:
- Sunglasses with UV protection whenever you are outdoors; the AAO names sunglasses as a protective measure, and EyeWiki says avoiding UV exposure is important for primary prevention;
- Protective eyewear against dust, for example in dusty work settings or on windy days;
- Artificial tears if your eyes feel dry; the AAO recommends them for dry eyes, and EyeWiki notes that lubricating the surface may help;
- Early checks if you have a pinguecula or a growth that is changing.
Protection also matters after surgery, because UV exposure is the reason the growth formed in the first place.
When to see a doctor about a pterygium
Seek same-day care from an eye doctor or eye emergency service if you have:
- a painful red eye with strong sensitivity to light;
- a white or grey spot on the cornea, or discharge;
- a sudden drop in vision;
- a chemical splash or an injury to the eye;
- redness or pain after pterygium surgery.
Book a routine appointment if you notice:
- a pink, wing-shaped growth on the white of the eye, even if it does not hurt;
- a growth that is getting bigger or moving toward the pupil;
- blurred vision, or glasses that no longer seem right;
- a red, irritated eye that does not settle with lubricating drops;
- an unusual-looking patch: white, dark or with irregular vessels, or growing quickly.
If you have already been told you need surgery, or are unsure, you can send your report and scans for a free review before you travel.
Frequently asked questions
A pterygium is a benign, wing-shaped growth of conjunctival tissue that starts at the edge of the cornea and spreads onto it. It is caused mainly by sunlight, wind and dust. Many are symptom-free; surgery removes the ones that cause problems.
The main cause is long-term exposure to ultraviolet light, with wind and dust contributing. It is more common in people near the equator, in older adults, in men and in people who work outdoors. It is not an infection and cannot be passed on.
Often none. When symptoms occur, they include a red, fleshy, wing-shaped growth, irritation and redness, a gritty or burning feeling, watering and blurred vision. Vision blur happens when the growth induces astigmatism or approaches the pupil.
A pinguecula is a yellowish bump on the white of the eye that does not reach the cornea, while a pterygium is a fleshy, vascular growth that crosses onto the cornea. Both are linked to sun, wind and dust, and a pinguecula can develop into a pterygium.
A pterygium is benign. It can harm vision by distorting or covering the cornea, so growing ones are removed. A few other surface growths can look similar, so tissue removed at surgery is routinely examined in the laboratory.
No drop removes a pterygium. Lubricating drops ease irritation, a short course of steroid drops can calm inflammation, and some decongestant drops reduce redness. Steroids and any prescription drops should be used only on a doctor's advice.
A pterygium does not normally shrink or disappear without treatment. Small ones can stay unchanged for years, while others slowly grow. Only an examination can tell you which kind you have.
It can. With a conjunctival autograft, recurrence is about 5–10%; if the growth is just cut away, it is about 80%. Most recurrences happen within the first year, so follow-up checks matter. Sun protection afterwards helps.
Pterygium removal is a routine eye operation performed by ophthalmologists in many countries. Whether the NHS funds it depends on your local NHS area and how much the growth affects you, so ask your GP or eye clinic. {{NHS access fact for pterygium surgery, if you want to state one}} If you prefer to be treated in Istanbul, send us your report and scans and your surgeon will tell you whether surgery is advisable and how many days you need to plan.
No. A pterygium on the nail is a skin and nail condition in which skin forms a wing-like extension over or under the nail. It is treated by a dermatologist and is unrelated to the eye condition.
Sources for the facts on this page
- American Academy of Ophthalmology. Pinguecula and Pterygium. https://www.aao.org/eye-health/diseases/pinguecula-pterygium
- EyeWiki (AAO). Pterygium. https://eyewiki.org/Pterygium
- EyeWiki (AAO). Pinguecula. https://eyewiki.org/Pinguecula
- Liu L, Wu J, Geng J, Yuan Z, Huang D. Geographical prevalence and risk factors for pterygium: a systematic review and meta-analysis. BMJ Open 2013. PubMed: https://pubmed.ncbi.nlm.nih.gov/24253031/
- Romano V, et al. Fibrin glue versus sutures for conjunctival autografting in primary pterygium surgery. Cochrane Database Syst Rev 2016. PubMed: https://pubmed.ncbi.nlm.nih.gov/27911983/
- Caputo R, et al. Pterygium inversum unguis: report of 19 cases and review of the literature. Arch Dermatol 1993. PubMed: https://pubmed.ncbi.nlm.nih.gov/8215496/
- Gondim VG, et al. Pterygium inversum unguis: report of an extensive case with good therapeutic response. J Drugs Dermatol 2013. PubMed: https://pubmed.ncbi.nlm.nih.gov/23545920/
Do you have a growth on the white of your eye, or have you been told you need pterygium surgery?
Send us your eye report or scans. Our cornea specialist, Doç. Dr. Muhammet Derda Özer, will review them and tell you whether monitoring, drops or removal surgery is the better choice, with no obligation.
3 eye surgeons
Your case is reviewed by a named surgeon, not a salesperson. Reply within {{response time}}.
Prof. Dr. Ahmet Satıcı
Doç. Dr. Muhammet Derda Özer
Op. Dr. Aysan Bayram