The dry eye: A diagnostic dilemma
The dry eye: A diagnostic dilemma
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DOI：
10.1097/00004397-199803840-00005
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发表时间：
1998-09-01
影响因子：
--
通讯作者：
Daniels, TE
中科院分区：
文献类型：
--
作者：
Whitcher, JP;Gritz, DC;Daniels, TE
干眼是一种非常有症状的疾病，在世界范围内发生，在许多情况下都可能发展。虽然它通常被称为干燥性角膜结膜炎或干燥性角膜炎，但其他术语可能用于指特定的干眼症。干眼症通常用于描述由维生素a缺乏引起的眼部干燥，而干眼症是指史蒂文斯-约翰逊综合征和其他严重结膜炎后出现的完全干燥的角化眼表。干燥综合征和干燥综合征也经常用于描述干眼与干燥综合征。为避免混淆，应使用通用术语干燥性角膜结膜炎（KCS）来表示干眼的存在，而不管相关综合征或疾病过程如何。尽管KCS是由许多不同的疾病引起的，但患者的症状却非常一致。眼部异物感、发红、瘙痒和不能流泪（即使在压力下）是普遍的症状。临床表现可能会有所不同，这取决于产生干燥的潜在疾病过程，但在每种情况下，导致KCS典型体征和症状的角膜和结膜损伤都是由泪膜改变介导的。眼泪是几种腺体分泌物的复杂混合物。泪液层是泪膜的主要组成部分，由Wolfring和Krause的泪腺和副泪腺分泌。水层漂浮在粘蛋白层上，粘蛋白层主要由结膜杯状细胞分泌。粘蛋白层起到表面润湿剂的作用，使水层平滑地展开，并在每次眨眼后覆盖在疏水性角膜上皮细胞上。浮在水层表面的，字面上就像浮在水上的油，是由油性脂肪和胆固醇酯组成的浅层脂质层，由眼睑边缘的睑板腺分泌。尽管脂质层的厚度通常不到100纳米，但它会覆盖在泪液膜上，形成一层完整的薄膜，阻止蒸发。（2,3）这种复杂的混合物浸泡在角膜和结膜表面，为上皮细胞提供湿润的环境。如果任何一种成分由于疾病而缺乏，典型的干眼症可能会发展。
The dry eye is an extremely symptomatic condition that occurs world-wide and can develop under many circumstances. Although it usually is termed keratoconjunctivitis sicca or keratitis sicca, other terms may be used to refer to specific dry-eye conditions. Xerophthalmia is a term usually used to describe ocular dryness secondary to vitamin A deficiency, whereas xerosis refers to the totally dry keratinized ocular surface seen after Stevens-Johnson syndrome and other severe forms of cicatrizing conjunctivitis. The terms sicca syndrome and sicca complex also are used frequently to describe the dry eye associated with Sjogrens syndrome. To avoid confusion, the generic term keratoconjunctivitis sicca (KCS) should be used to indicate the presence of a dry eye, regardless of the associated syndrome or disease process. Even though KCS is caused by a number of different diseases, the patient's symptoms are remarkably consistent. Complaints of ocular foreign-body sensation, redness, itching, and inability to produce tears (even under stress) are universal. Clinical findings may vary, depending on the underlying disease process producing the dryness but, in every case, the damage to the cornea and conjunctiva responsible for the typical signs and symptoms of KCS is mediated by an alteration in the tear film.(1)The tears are a complex mixture of the secretions of several glands. The aqueous tear layer, which comprises the bulk of the tear film, is secreted by the lacrimal gland proper and the accessory lacrimal glands of Wolfring and Krause. The aqueous layer floats on a mucin layer secreted mainly by the conjunctival goblet cells. The mucin layer acts as a surface-wetting agent, allowing the aqueous layer to spread out smoothly and to coat the hydrophobic corneal epithelial cells after each blink of the eyelids. Floating on the surface of the aqueous layer, literally like oil on water, is the superficial lipid layer composed of oily aliphatic and cholesterol esters secreted by the meibomian glands along the margin of the eyelid. Even though the lipid layer usually is less than 100 nm thick, it spreads over the aqueous tear film, forming a complete thin cover that retards evaporation.(2,3) This complex mixture bathes the surface of the cornea and conjunctiva and provides a moist milieu for the epithelial cells. If any of the components is lacking as a result of disease, a typical dry-eye syndrome may develop.