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Thursday, December 23, 2010

Pingueculitis

SIGNS AND SYMPTOMS
Pingueculae are characterized by yellowish, slightly raised, interpalpebral lipid-like deposits in the nasal and temporal limbal conjunctiva. They are found frequently in individuals who are middle-aged and who experience chronic exposure to the sun. There is no predilection for sex or race.

In most cases, pingueculae are an ancillary finding, causing little, if any, ocular symptoms. Frequently, pingueculae can lead to the formation of pterygia. Both pingueculae and pterygia can become vascularized and inflamed, and may be associated with corneal punctate epitheliopathy and corneal dellen (corneal thinning secondary to dryness).

Pingueculitis occurs when a pinguecula becomes acutely inflamed, vascularized, red, irritated and highly symptomatic.

PATHOPHYSIOLOGY
Pinguecula formation is typically seen in the older population and is considered by most researchers to be a conjunctival degenerative processes initiated by exposure to noxious environmental stimuli and UV light. The initial lesion is thought to result from chronic solar radiation, which alters the collagen and elastic tissues of the conjunctival stroma and leads to elastotic degeneration and deposition of abnormal elastic fibers in the conjunctival substantia propria.

Once a pinguecular elevation forms-depending on its size-the tear film may become thin and discontinuous in that zone, producing a bed of dryness. When the lesion is inflamed, vascular dilation allows the release of histamine, seratonin, bradykinin and prostaglandins, producing the acute irritation that characterize pingueculitis. In severe cases the conjunctival surface becomes sufficiently dry to cause microulceration of the conjunctival epithelium. When this occurs, the eye protects itself by attempting to cover the erosion, leading to pterygium formation.

MANAGEMENT
Manage pinguecula based on symptomatology. For patients with occupations or hobbies that increase the risk of pinguecula, counsel them on the preventative benefits of sunwear, UV-blocking coatings or goggles that limit dust exposure.

In cases of mild pingueculitis, where symptoms are mild or when dellen are present, use ocular lubricating drops such as Tears Naturale II or ointments such as Refresh PM or Lacrilube. When symptoms and inflammation become significant, appropriate topical steroids, used Q2H to QID, include fluorometholone 0.25% (Flarex), 1% rimexolone acetate (Vexol), 0.12% prednisolone acetate suspension (Pred Mild), 0.12% prednisolone sodium phosphate solution (Inflamase Mild), 1% prednisolone acetate suspension (Pred Forte) 1% prednisolone sodium phosphate solution (Inflamase Forte).

Consider surgical resection in severe cases where pterygia are present and are interfering with vision, contact lens wear or corneal wetting.

CLINICAL PEARLS

If you discover an intrapalpebral conjunctival mass or elevation, consider the differential diagnosis. Lesions such as these are not all benign, and include conjunctival dermoid (a white mass seen in Goldenhar's syndrome), cancerous or precancerous conjunctival intraepithelial neoplasia (a unilateral, white, vascularized mass), phlyctenulosis (a white, steep mass associated with Staphylococcus hypersensitivity and tuberculosis), pannus (a fibrovascular conjunctival growth on the cornea associated with severe dry eye, chlamydial infection, chemical or thermal injury), conjunctival retention cyst (a clear, fluid-filled sac) and limbal follicle.

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