Pinguecula

Key Points at a Glance

1. What Is Pinguecula?

A pinguecula is a yellowish-white to yellowish-brown small elevation that develops on the bulbar conjunctiva in the interpalpebral region, with the corneal limbus as its base. It is a fibrofatty degenerative tissue that does not invade the cornea. The name derives from the Latin word pinguis (fat). It is often structureless, but occasionally a lobulated internal structure may be observed. It frequently forms a triangle with the corneal side as the base, and may also appear oval or irregularly shaped.

Prevalence increases with age, and after the age of 50, it is observed to some degree in most people. It is the most common conjunctival degeneration and one of the most noticeable age-related changes. It has long been known to occur more frequently in low-latitude regions, suggesting a causal relationship with ultraviolet exposure. It commonly occurs on the nasal side but can also appear on the temporal side or bilaterally. It is usually binocular.

Epidemiology (Prevalence)

Pinguecula increases sharply with age. In a Spanish population-based epidemiological study (O Salnés study), the prevalence of pinguecula in individuals aged 40 and older was reported to be approximately 47.9%, with 47.2% on the nasal side and 6.0% on the temporal side¹⁾. The same study found that pinguecula was significantly more frequent than pterygium, and age and outdoor activity time were identified as independent risk factors¹⁾. A community-based survey in South India reported even higher prevalence rates, particularly among outdoor workers and the elderly, with outdoor work hours and age identified as risk factors²⁾. While population-based studies specific to Japan are limited, it is almost universally observed as an age-related change after the age of 50.

Pinguecula rarely causes symptoms despite its high prevalence and is often discovered incidentally during routine examinations. However, epidemiologically, the presence of pinguecula itself is recognized as a risk factor for conjunctivochalasis and dry eye disease, and is also listed as a representative example of anatomical irregularity of the ocular surface in the TFOS DEWS III report³⁾.

ICD-10 code: H11.1.

Q Can pinguecula become malignant?

Pinguecula is a non-malignant age-related change and does not become malignant. It may slowly enlarge but does not cause visual impairment. However, differentiation from other conjunctival lesions such as conjunctival intraepithelial neoplasia (CIN) or conjunctival nevus may be necessary. For details, see the Diagnosis and Examination Methods section.

2. Main Symptoms and Clinical Findings

J Clin Med. 2025 Dec 30; 15(1):289. Figure 1. PMCID: PMC12786677. License: CC BY.

A clinical photograph and anterior segment OCT are shown side by side, correlating a yellowish-white conjunctival elevation with localized thickening near the corneal limbus. The position and height of the superficial elevated lesion arising near the limbus are demonstrated.

Subjective Symptoms

Most pingueculae are asymptomatic. Patients often have no complaints other than being concerned about their appearance, and are discovered incidentally during health checkups or examinations for other diseases.

When symptoms occur, the following findings are representative.

Foreign body sensation and dryness: When the elevation is severe and contacts the corneal limbus, it causes abnormal tear distribution, presenting dry eye-like symptoms. The physical elevation of pinguecula alters the alignment between the eyelid and eyeball, affecting tear spread and function³⁾
Hyperemia: Occurs when pingueculitis develops. Localized hyperemia is observed centered on the pinguecula.
Contact lens discomfort: In soft contact lens wearers, the edge of the lens rubs against the raised pinguecula, making the eye more prone to hyperemia. It is pulled by the upper eyelid during blinking, which can also contribute to conjunctivochalasis

Clinical Findings

Yellow-white raised lesion: Found on the interpalpebral bulbar conjunctiva. It is often triangular with the base facing the cornea, but may also be oval or irregular in shape. A lobular internal structure may be observed
Tear film instability: Fluorescein staining can reveal tear film breakdown around the raised area. Conjunctival erosion is also stained with lissamine green and is easier to observe when combined with a blue-free filter
Delle: When the elevation is pronounced, thinning of the adjacent peripheral cornea due to drying (delle) may occur. This is thought to result from discontinuity of the tear meniscus
Pingueculitis: Localized hyperemia centered on the pinguecula, sometimes accompanied by an epithelial defect at the apex of the lesion
Bilaterality: Often occurs in both eyes

3. Causes and Risk Factors

Etiology

Ultraviolet (UV) exposure is deeply involved in the development of pinguecula, and a pathogenesis similar to that of pterygium formation is suspected^3,4). Proteins such as collagen and elastin in the subconjunctival tissue are thought to undergo post-translational modifications such as glycation or racemization, becoming resistant to degradation and forming abnormal aggregates.

At the molecular level, elevated nuclear p53 protein expression due to UV-induced DNA damage response has been reported in both pinguecula and pterygium⁴⁾. In pterygium, increased expression of p53 and MDM2 (mouse double minute 2) has been confirmed, and a similar mechanism is thought to be involved in pinguecula, which lies on the same UV-induced degenerative spectrum.

Reason for Nasal Predilection

The reason why both pterygium and pinguecula occur more frequently on the nasal side is thought to be that light passing through the cornea medially focuses on the area of the nasal limbus, while the shadow of the nose reduces light intensity on the temporal side. This optical focusing mechanism is widely cited as a pathological model for pterygium⁴⁾.

Risk Factors

Ultraviolet exposure: The most important environmental factor. Prevalent in low-latitude regions.
Aging: Prevalence increases markedly after age 50^1,2).
Wind and dust: Chronic environmental irritation.
Outdoor work and outdoor living: Increased UV exposure time. Outdoor workers have a significantly higher risk²⁾.
Male sex: Many reports indicate a higher incidence in men than in women²⁾.
Smoking: Considered a risk factor.

Pinguecula

Location: Remains on the bulbar conjunctiva and does not invade the cornea.

Shape: Yellow-white elevation. Triangular to elliptical.

Treatment: Usually observation. Eye drops for inflammation.

Pterygium

Location: Triangular invasion from the conjunctiva onto the cornea.

Shape: White membranous tissue rich in blood vessels. Destroys Bowman’s membrane.

Treatment: Surgery when visual function is impaired (e.g., conjunctival flap transplantation).

Some believe that pinguecula can be a precursor to pterygium. Inflammatory pinguecula with nasal corneal epithelial defects is considered to carry a high risk of progression to pterygium. However, not all pingueculae progress to pterygium, and progression is slow.

Q Can pinguecula turn into pterygium?

Pinguecula is considered a possible precursor lesion to pterygium, but not all cases progress to pterygium. Enlargement is gradual, and ultraviolet protection may help slow progression. See the comparison table above for differences from pterygium.

4. Diagnosis and Examination Methods

Basic Evaluation

Pinguecula can be easily diagnosed with slit-lamp microscopy. Special tests are usually unnecessary.

Slit-lamp microscopy: Confirm a yellowish-white elevation in the interpalpebral region. Confirm bilateral and nasal-side predominance.
Fluorescein staining: Evaluate tear film instability around the elevation, conjunctival epithelial erosion, and the presence of dellen.
Lissamine green staining: Useful for evaluating conjunctival epithelial erosion. Observation is easier with a blue-free filter.
Anterior segment optical coherence tomography (OCT): Used to monitor lesion thickness. Also useful for differentiating from pterygium.

Biopsy for histopathological confirmation is usually unnecessary, but may be indicated in atypical cases to differentiate from conjunctival intraepithelial neoplasia (CIN).

Differential Diagnosis

Condition	Key points for differential diagnosis
Pterygium	Triangular invasion onto the cornea. Destroys Bowman’s membrane.
Pseudopterygium	Scar tissue from conjunctival adhesion to the cornea after trauma or inflammation
Conjunctival intraepithelial neoplasia (CIN/OSSN)	Hyperemia, pigmentation, papillary growth. Atypical cases require biopsy.
Corneal limbal dermoid	Congenital, yellowish-white elevation, straddling the corneal limbus
Conjunctival nevus	Pigmented lesion, present since childhood

Histological findings

The essence of pinguecula is elastic fiber degeneration beneath the conjunctival epithelium.

HE stain: basophilic degeneration in the lamina propria of the conjunctiva
Elastica van Gieson stain (elastic fiber stain): basophilic areas stain blackish-brown. This is so-called elastoid degeneration.
Verhoeff elastic fiber stain: disorganization of collagen fibers beneath the conjunctival epithelium and eosinophilic elastic fiber degeneration are visualized.
Covering epithelium: often thins, but may also present hyperplasia or dysplasia.
Increased nuclear p53: suggests evidence of DNA damage due to UV exposure⁴⁾

5. Standard Treatment

Observation

Asymptomatic pinguecula does not require treatment; observation alone is sufficient. It is important to explain to the patient that there is no risk of malignant transformation and that it is an age-related change that may enlarge slowly.

Pharmacotherapy for Pingueculitis

When inflammation occurs in the pinguecula (pingueculitis), topical eye drop treatment is administered. Representative Japanese ophthalmology treatment guidelines recommend the following combination regimen.

Levofloxacin ophthalmic solution (1.5%) 4 times daily: used in combination for infection prevention
Fluorometholone ophthalmic solution (0.1%) 4 times daily: Inflammation suppression with low-concentration steroids
The above combination is a common prescription example

Additionally, nonsteroidal anti-inflammatory drug (NSAID) eye drops (such as indomethacin ophthalmic solution) are used to reduce inflammatory symptoms. The fact that “steroid eye drops are effective in treating pingueculitis” is also emphasized in Japanese slit-lamp microscopy clinical textbooks.

For dry eye-like symptoms caused by abnormal tear distribution, artificial tears or sodium hyaluronate ophthalmic solution (0.1% or 0.3%) are prescribed to stabilize the tear film.

Steroid eye drop use should generally be limited to the short term. Long-term use carries risks of increased intraocular pressure and cataracts, so the dosage should be reduced and discontinued promptly after symptom improvement.

Surgical Treatment

Surgical excision is considered when medical treatment is ineffective, when it interferes with contact lens wear, or when it is cosmetically prominent. At the pinguecula stage, active excision is rarely performed, and conservative treatment is prioritized.

Technique: Performed in a manner similar to simple excision or conjunctival flap transplantation for pterygium
Conjunctival autograft: This is the standard procedure after excision in the pterygium field, with a reported recurrence rate of 1.9–8%⁴⁾. The same method is applied analogously in pinguecula excision.
Fibrin glue fixation: A method of fixing the graft with fibrin glue instead of sutured conjunctival autograft is widely used, contributing to shorter surgical time and reduced postoperative inflammation⁴⁾
Improvement of postoperative dry eye symptoms: Surgical excision of pinguecula has been reported to improve dry eye signs and symptoms by correcting ocular surface irregularities³⁾. However, high-quality evidence on this point is limited, and excision based solely on DED complaints is not recommended³⁾
Preoperative explanation: Explain in advance that recurrence may occur after surgery, symptoms such as hyperemia may not completely resolve, and that excision for cosmetic purposes alone should be carefully considered

Management of Dry Eye Associated with Pinguecula

Pinguecula is listed in the TFOS DEWS III report as a representative example of anatomical abnormalities of the ocular surface, and it is clearly indicated that it induces and exacerbates dry eye through shortened tear film breakup time (TBUT) and tear distribution abnormalities³⁾. Clinically, the following stepwise treatment is recommended.

First step: Regular lubrication with preservative-free artificial tears or sodium hyaluronate eye drops
Second step: Short-term concomitant use of low-concentration fluorometholone 0.1% when pingueculitis is present
Third step: Consider surgical excision only in cases unresponsive to conservative treatment or when cosmetically prominent

Pinguecula and conjunctivochalasis share risk factors, and the presence of pinguecula has also been reported as an independent risk factor for conjunctivochalasis³⁾. In cases where poor tear dynamics lead to refractory symptoms, evaluate both conditions together.

Q Can pinguecula be removed by surgery?

Surgical removal is possible, but there is a risk of recurrence, and redness may not completely disappear. Removal for cosmetic reasons alone should be carefully considered; conservative treatment (artificial tears, low-concentration steroid eye drops) is generally tried first. Surgery may be indicated when pingueculitis recurs repeatedly or when it interferes with contact lens wear.

6. Pathophysiology and Detailed Mechanisms

Molecular-Level Changes

Pinguecula is essentially caused by degeneration of collagen fibers beneath the conjunctival epithelium and accumulation of abnormal proteins. Ultraviolet exposure disrupts the collagen fibers under the conjunctival epithelium, leading to elastoid degeneration. When proteins such as collagen and elastin undergo post-translational modifications such as glycation or racemization, they become resistant to protease degradation. These degradation-resistant proteins accumulate as abnormal aggregates, forming yellowish-white elevations.

p53 and Ultraviolet Radiation

Increased nuclear p53 protein expression is observed in the epithelium of pinguecula and pterygium. p53 is a tumor suppressor that normally induces apoptosis or cell cycle arrest in response to cellular stress. In pterygium studies, both p53 and its antagonist MDM2 are strongly expressed, with p53 trapped in the cytoplasm and unable to exert transcriptional activity⁴⁾. Furthermore, it has been shown that p53 reactivation by the MDM2 antagonist Nutlin can selectively induce apoptosis in pterygium cells⁴⁾. Pinguecula is thought to lie on the same UV-induced degenerative spectrum as pterygium, and these molecular mechanisms may also be applied to understanding the pathogenesis of pinguecula.

Effects on Tear Film Dynamics

The elevation of pinguecula alters the alignment between the eyelid and the ocular surface, affecting tear film distribution and function³⁾. When the elevation is pronounced, discontinuity of the tear meniscus occurs, forming a dry delle (dell) in the adjacent peripheral cornea. The TFOS DEWS III report treats pinguecula as a representative example of “anatomical irregularity of the ocular surface,” and its contribution to dry eye pathology is clearly stated³⁾. It has also been suggested that when ocular surface irregularity improves after surgical excision, the signs and symptoms of dry eye are reduced³⁾.

7. References

Viso E, Gude F, Rodríguez-Ares MT. Prevalence of pinguecula and pterygium in a general population in Spain. Eye (Lond). 2011;25(3):350-357. PMID: 21183945.
Asokan R, Venkatasubbu RS, Velumuri L, Lingam V, George R. Prevalence and associated factors for pterygium and pinguecula in a South Indian population. Ophthalmic Physiol Opt. 2012;32(1):39-44. PMID: 22112236.
TFOS DEWS III Management and Therapy Subcommittee. TFOS DEWS III: Management and Therapy Report (Section 8.1.3 Pinguecula). Ocul Surf. 2025.
Chu WK, Choi HL, Bhat AK, Jhanji V. Pterygium: new insights. Eye (Lond). 2020;34(6):1047-1050. PMID: 32029918.

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