Pterygium

A pterygium is a benign, wedge-shaped growth of conjunctival tissue that extends onto the cornea. Often called "surfer's eye," this condition is strongly associated with chronic sun exposure and environmental irritants, appearing as a raised, fleshy growth on the white part of the eye.

Overview

Pterygium is a common ocular surface disorder characterized by the encroachment of a fibrovascular growth from the conjunctiva onto the cornea. The name derives from the Greek word "pterygion," meaning "little wing," which describes its wing-like appearance. While benign and non-cancerous, pterygium can cause significant visual and cosmetic concerns if left untreated.

This condition is particularly prevalent in populations living near the equator, in what's known as the "pterygium belt" between 30 degrees north and south latitude. The incidence is highest among individuals with significant outdoor exposure, particularly those involved in farming, fishing, and water sports. Studies show prevalence rates ranging from 2% to over 20% in different populations, with higher rates in tropical and subtropical regions.

Pterygium typically develops on the nasal side of the eye but can occur temporally or on both sides. While often asymptomatic in early stages, progressive growth can lead to irregular astigmatism, ocular irritation, and in severe cases, vision loss from corneal involvement. Understanding risk factors and early intervention can help prevent progression and preserve visual function.

Symptoms

The symptoms of pterygium can vary from being completely asymptomatic to causing significant discomfort and visual disturbance. The severity of symptoms often correlates with the size and location of the growth, as well as the degree of inflammation present.

Common Symptoms

Associated Symptoms

  • Symptoms of eye - General eye discomfort and irritation
  • Burning or stinging sensation
  • Itching of the affected eye
  • Dryness and grittiness
  • Light sensitivity (photophobia)
  • Cosmetic concerns due to visible growth

Progressive Symptoms

  • Astigmatism - Irregular corneal shape causing distorted vision
  • Double vision (diplopia) in severe cases
  • Restriction of eye movement with large pterygia
  • Corneal scarring in advanced cases

Interestingly, some symptom data shows association with acne or pimples, which may relate to similar inflammatory pathways or environmental factors affecting both skin and ocular surface health.

Causes

The exact cause of pterygium is multifactorial, with chronic ultraviolet (UV) radiation exposure being the primary risk factor. The pathogenesis involves complex interactions between environmental factors and cellular responses.

Primary Causes

  • UV radiation: Chronic exposure to UVA and UVB rays causing DNA damage and oxidative stress
  • Environmental irritants: Dust, wind, smoke, and air pollution
  • Dry eye conditions: Chronic tear film instability
  • Heat exposure: High temperatures and low humidity

Pathophysiology

  • Limbal stem cell dysfunction: UV damage to stem cells at the corneal-conjunctival junction
  • Altered growth factors: Increased expression of VEGF, TGF-β, and other cytokines
  • Matrix metalloproteinase activation: Enzymes that break down extracellular matrix
  • Inflammatory cascade: Chronic inflammation promoting fibrovascular proliferation
  • P53 gene mutations: UV-induced mutations similar to skin cancers

Contributing Factors

  • Genetic predisposition: Family history and certain genetic polymorphisms
  • Human papillomavirus (HPV): Some studies suggest possible viral involvement
  • Oxidative stress: Imbalance between free radicals and antioxidants
  • Immunologic factors: Altered immune response in ocular surface

Risk Factors

Understanding risk factors for pterygium can help in prevention and early intervention:

  • Geographic location: Living near the equator or at high altitudes
  • Outdoor occupation: Farmers, fishermen, construction workers, lifeguards
  • Age: Most common between 20-50 years, but can occur at any age
  • Gender: Slightly more common in males due to occupational exposure
  • Sun exposure: Chronic exposure without eye protection
  • Environmental conditions: Dry, dusty, windy climates
  • Water sports: Surfing, sailing, swimming (reflected UV radiation)
  • Lack of eye protection: Not wearing sunglasses or hats
  • Rural living: Higher exposure to dust and UV radiation
  • Previous pterygium: Recurrence after surgical removal
  • Family history: Genetic susceptibility
  • Ethnicity: Higher prevalence in certain ethnic groups

Diagnosis

Diagnosis of pterygium is primarily clinical, based on characteristic appearance and location. A comprehensive eye examination can determine the extent of involvement and guide treatment decisions.

Clinical Examination

  • Visual inspection: Characteristic triangular, fleshy growth
  • Slit-lamp biomicroscopy: Detailed examination of pterygium morphology
  • Visual acuity testing: Assessment of vision impact
  • Refraction: Detection of induced astigmatism
  • Tear film assessment: Evaluation of dry eye component

Grading Systems

  • Tan's grading: Based on pterygium translucency (T1-T3)
  • Morphological grading: Based on extent of corneal involvement
  • Activity grading: Assessment of inflammation and vascularity

Advanced Imaging

  • Anterior segment OCT: Measures thickness and corneal involvement
  • Corneal topography: Maps astigmatism and irregularities
  • Confocal microscopy: Cellular-level examination
  • Photography: Documentation for monitoring progression

Differential Diagnosis

  • Pinguecula: Similar growth that doesn't extend onto cornea
  • Conjunctival carcinoma: Malignant growth requiring biopsy
  • Pseudopterygium: Secondary to trauma or inflammation
  • Limbal dermoid: Congenital lesion
  • Pannus: Vascular growth from chronic inflammation

Treatment Options

Treatment of pterygium depends on the size, symptoms, and visual impact. Management ranges from observation and conservative measures to surgical excision for progressive or symptomatic cases.

Conservative Management

  • Observation: For small, asymptomatic pterygia
  • Artificial tears: Lubrication to reduce irritation and dryness
  • Anti-inflammatory drops:
    • Mild corticosteroids for acute inflammation
    • NSAIDs for chronic irritation
    • Cyclosporine for associated dry eye
  • Vasoconstrictor drops: Temporary cosmetic improvement
  • UV protection: Wraparound sunglasses and wide-brimmed hats

Surgical Indications

  • Visual axis involvement threatening vision
  • Induced astigmatism >1.5 diopters
  • Chronic inflammation unresponsive to medical therapy
  • Restriction of ocular motility
  • Significant cosmetic concerns
  • Interference with contact lens wear

Surgical Techniques

  • Bare sclera excision: Simple removal (high recurrence rate)
  • Conjunctival autograft: Gold standard with lowest recurrence
    • Superior conjunctiva harvested and transplanted
    • Secured with sutures or fibrin glue
  • Amniotic membrane transplantation: Alternative when autograft unavailable
  • Limbal-conjunctival autograft: Includes limbal stem cells

Adjuvant Therapies

  • Mitomycin C: Antimetabolite to reduce recurrence
  • 5-Fluorouracil: Alternative antimetabolite
  • Beta radiation: Postoperative treatment
  • Anti-VEGF injections: For recurrent cases

Postoperative Care

  • Topical antibiotics: Prevent infection
  • Corticosteroid drops: Reduce inflammation (tapered over weeks)
  • Lubricants: Promote healing
  • UV protection: Essential to prevent recurrence
  • Regular follow-up: Monitor for complications and recurrence

Prevention

Prevention of pterygium focuses on minimizing UV exposure and environmental irritants:

  • UV protection: Wear wraparound sunglasses with 100% UV protection
  • Wide-brimmed hats: Additional protection from overhead sun
  • Avoid peak UV hours: Limit outdoor exposure between 10 AM and 4 PM
  • Protective eyewear: In dusty or windy environments
  • Artificial tears: Regular use in dry conditions
  • Workplace safety: Appropriate eye protection for outdoor workers
  • Children's protection: Start UV protection early in life
  • Regular eye exams: Early detection and monitoring
  • Avoid eye rubbing: Can worsen irritation
  • Stay hydrated: Helps maintain tear film
  • Consider polarized lenses: Reduce glare from reflective surfaces
  • Indoor humidity: Use humidifiers in dry environments

When to See a Doctor

Seek ophthalmologic evaluation if you experience:

  • Visible growth on the white part of the eye
  • Persistent eye redness that doesn't improve
  • Foreign body sensation lasting more than a few days
  • Changes in vision or diminished vision
  • Eye pain or significant discomfort
  • Rapid growth of existing pterygium
  • Interference with contact lens wear
  • Cosmetic concerns affecting quality of life
  • Recurrent inflammation despite treatment
  • Any suspicious changes in appearance

Early evaluation can help determine if treatment is needed and prevent progression that might require more complex surgical intervention.

Frequently Asked Questions

Can pterygium grow back after surgery?

Yes, recurrence rates vary from 5-40% depending on the surgical technique used. Conjunctival autograft with proper postoperative care has the lowest recurrence rate, typically less than 10%.

Is pterygium cancerous?

No, pterygium is a benign (non-cancerous) growth. However, any unusual growth should be evaluated by an eye care professional to rule out other conditions.

Can pterygium affect both eyes?

Yes, bilateral pterygium occurs in about 25-30% of cases. When both eyes are affected, they may progress at different rates.

Will pterygium go away on its own?

No, pterygium does not resolve spontaneously. While growth may be slow or stop, the tissue will not disappear without surgical removal.

How long is recovery after pterygium surgery?

Initial healing takes 2-4 weeks, but complete recovery may take 2-3 months. Most patients can return to normal activities within a week, avoiding swimming and dusty environments during healing.

References

  1. Hovanesian JA, et al. Surgical techniques and adjuvants for the management of pterygium. Int Ophthalmol Clin. 2017;57(2):93-104.
  2. Singh P, et al. Pterygium: epidemiology prevention and treatment. Community Eye Health. 2017;30(99):S5-S6.
  3. Clearfield E, et al. Conjunctival autograft for pterygium. Cochrane Database Syst Rev. 2016;2:CD011349.
  4. Janson BJ, Sikder S. Surgical management of pterygium. Ocul Surf. 2014;12(2):112-119.
  5. Liu L, et al. Geographical prevalence and risk factors for pterygium: a systematic review and meta-analysis. BMJ Open. 2013;3(11):e003787.