I. Pingueculae Pingueculae are horizontal, triangular or oval, elevated, grayish-yellow bulbar conjunctival nodules at the angle-scleral margin junction of the lid fissure. Pathology shows hyaline degeneration of the subepithelial junction of the pingueculae with increased basophilic elastic fibers and granular material, usually without inflammatory cells, which is thought to be the result of UV-induced collagen degeneration. The lid fissures are mainly located in the nasal region and are therefore thought to be directly related to the reflection of sunlight from the nasal bridge, resulting in photochemical damage. In addition, repetitive damage to the bulbar conjunctiva in the lid fissure area caused by eyelid closure is also thought to be a causative factor, [Clinical presentation] occurring more frequently on the nasal side than on the temporal side, mostly bilaterally. The appearance often resembles lipid infiltration into the upper subcutaneous tissue, which contains yellow, transparent elastic tissue. The lid fissure appears as a triangular raised patch in the bulbar conjunctiva near the corneal limbus, with the base of the triangle directed toward the cornea. Blepharospasm is usually asymptomatic and is at best a cosmetic concern. Occasionally, blepharospasm may become congested, the surface may become rough, and blepharitis may occur. Blepharospasm is rarely confused with other lesions. Blepharospasm is located under the epithelium, and epithelial tumors are mostly confined to the epithelial tissue. Gaucher disease in adults is a sphingolipid metabolic disorder that can develop brown lid lacrimation-like lesions and requires careful differentiation. Treatment] No treatment is usually necessary. In adults, Gaucher’s disease is a metabolic disease of sphingolipids and can occur with brown sphingolipid-like lesions. Removal may be considered if it seriously affects the appearance, if there is recurrent chronic inflammation, or if it interferes with the successful fitting of corneal contact lenses. Pterygium A pterygium (pterygia) is a fibrovascular-like tissue that grows towards the surface of the cornea and is attached to the conjunctiva, often in the nasal lid area. The presence of a pterygium not only affects aesthetics, but also causes corneal astigmatism leading to vision loss and can seriously affect the patient’s vision if the pterygium obscures the visual axis area. The exact cause and pathogenesis of pterygium has not yet been fully understood, but epidemiology shows that two factors are closely related to its occurrence: the geographical location of the area where one lives, and the exposure to sunlight and sand. The incidence of pterygium is higher than normal in residents of tropical areas and in those who work outdoors for long periods of time, suggesting that ultraviolet light from sunlight may be the main cause of pterygium. In addition, genetics is a significant factor in the development of pterygium, with family members with a history of pterygium being more likely than normal to develop pterygium. Many other factors, including local tear abnormalities, type I allergic reactions, and human papillomavirus infection, are thought to be important in the development of pterygium. Clinical manifestations] The onset of pterygium is usually bilateral, with the nasal side being the most common. When the lesion is close to the pupillary area of the cornea, it can cause vision loss due to corneal astigmatism or direct occlusion of the pupillary area. The hypertrophic bulbar conjunctiva and its underlying fibrovascular tissue invade the cornea in a triangular pattern and can impede eye movement when the pterygium is large (Figure 7-10). The typical pterygium can be divided into three parts: head, neck, and body, with no clear demarcation between them. The body of the pterygium usually arises from the bulbar conjunctiva and occasionally from the semilunar crease or the conjunctiva of the dome (especially in recurrent pterygium). The body of the pterygium turns into the neck at the corneoscleral margin. The head of the pterygium refers to the portion of the cornea where the pterygium is located in close proximity to the underlying cornea. stocker’s line refers to the deposition of metal-containing pigment in the epithelium, and its presence is often an indication of slow growth of the pterygium. Differences in the appearance of the pterygium often suggest different stages of lesion development: progressive pterygium is congested and hypertrophic, and quiescent pterygium is grayish, thin, and membranous. The diagnosis of pterygium is not difficult due to the intuitive nature of the lesion, but it needs to be differentiated from a number of other diseases. Pseudopterygium Pseudopterygium is an adhesion of the conjunctiva to the cornea due to trauma, surgery, and inflammation that injures the limbal area of the cornea. It differs from true pterygium in that it does not have a clear head, body, or tail shape; it can occur anywhere in the cornea; there is often a clear history of prior trauma and inflammation; and the underside of the pseudopterygium can often be passed by a probe. Pseudopterygium The pseudopterygium is located in the lid area on both sides of the cornea in the bulbar conjunctiva, slightly elevated above the conjunctiva, and has a yellowish-white triangular appearance. Its cause is also associated with prolonged outdoor activity, but lid fissures rarely invade the cornea. Conjunctival tumors Some tumors of the conjunctiva are easily confused with pterygium in the early stages of development, but benign tumors generally rarely invade the cornea, whereas malignant tumors grow rapidly and have an irregular appearance. Pathological examination can clarify the diagnosis. Treatment】Pterygium is generally not treated when it is small and stationary, but stimulation by sand and sunlight should be reduced as much as possible. Progressive development of pterygium and invasion of the pupillary area can be treated surgically, but there is a certain rate of recurrence. Surgical options are simple pterygium excision or subconjunctival transfer. Pterygium excision + bulbar conjunctival flap transfer, transplantation or amniotic membrane transplantation. Combination of corneal limbal stem cell transplantation, autologous conjunctival transplantation, beta-irradiation, and topical mitomycin can reduce the recurrence rate of pterygium. Conjunctival concretion is a yellowish-white concretion that appears on the surface of the lid conjunctiva, commonly in patients with chronic conjunctivitis or in the elderly. Conjunctival concretions are formed by the solidification of detached epithelial cells and degenerated white blood cells. They are usually asymptomatic and do not require treatment. If the stone protrudes from the conjunctival surface causing a foreign body sensation and resulting in corneal abrasion, it may be removed with a foreign body needle or sharp knife under surface anesthesia.