血泪是指因各种原因导致眼部流出血性泪液的症状，其病因和临床表现复杂多样，往往涉及多学科多专业。不同病因引起的血泪，无论是临床表现，还是诊治方法均差异很大。为了向临床医生提供可参考的血泪临床诊疗流程，中国医师协会眼科医师分会泪器病专业委员会及中国中西医结合学会眼科专业委员会泪器病学组组织有关专家以临床实践经验为基础，经过认真讨论建立本共识，对血泪的病因、临床特征及诊疗流程提出指导性意见。

Bloody tears refers to the symptoms of blooding tears flowing from the eye due to various reasons. Its etiology and clinical manifestations are complex and diverse, often involving multiple disciplines and specialties. In order to provide clinicians with a reference for the clinical diagnosis and treatment process of bloody tears, Lacrimal Diseases Professional Committee of Ophthalmologist Branch of Chinese Medical Doctor Association and Lacrimal Diseases Group of Ophthalmic Professional Committee of Chinese Association of Integrated Medicine organized relevant experts to establish this consensus based on clinical practice after serious discussion, and put forward guiding opinions on the etiology, clinical characteristics, and diagnosis and treatment process of bloody tears.

目的：探讨泪液中前列腺素E2(prostaglandin E2，PGE2)水平与干眼严重程度的关系。方法：选取干眼患者60例，并接受眼表疾病指数(Ocular Surface Disease Index，OSDI)问卷调查及眼科检查，包括泪膜破裂时间(tear film breakup time，BUT)、角膜荧光素染色评分(corneal fuorescein staining score，CFLS)、泪液分泌试验(Schirmer I试验)。使用酶联免疫吸附测定(ELISA)测量泪液中PGE2的水平。分析泪液PGE2水平与干眼临床症状相关指标的关系。结果：干眼患者泪液中的PGE2水平为(446.39±139.34) pg/mL。干眼患者泪液中PGE2水平与OSDI评分呈正相关(r=0.458，P<0.001)。泪液PGE2水平与BUT(r=0.164，P=0.354)、CFLS评分(r=0.265，P=0.086)、Schirmer I试验(r=?0.076，P=0.460)均无明显相关性。应用线性回归分析表明，泪液PGE2水平与OSDI评分呈正相关(95%CI：7.04~20.18，t=4.01，P<0.001)。结论：泪液中PGE2的水平与OSDI评分呈正相关，与BUT、CFLS评分、Schirmer I试验均无明显相关性。

Objective: To investigate the relationship between the level of prostaglandin E2 (PGE2) in tears and the severity of dry eye. Methods: Sixty patients with dry eye were selected and investigated with the Ocular Surface Disease Index (OSDI) questionnaire and ophthalmic examination, including tear film break-up time (BUT), corneal fluorescein staining score (CFLS) and tear secretion test (Schirmer I test). The level of PGE2 in tears was measured by enzyme-linked immunosorbent assay (ELISA). The relationship between the level of PGE2 in tears and related indexes of dry eye clinical symptoms was analyzed. Results: The average level of PGE2 in tears of patients with dry  eye was (446.39±139.34) pg/mL. The level of PGE2 in tears of patients with dry eye was positively correlated with the OSDI score (r=0.458, P<0.001). PGE2 levels were not significantly correlated with BUT (r=0.164, P=0.354),Schirmer I score (r=?0.076, P=0.460), and CFLS score (r=0.265, P=0.086). Linear regression analysis showed that the level of PGE2 in tears was positively correlated with OSDI score (95% CI: 7.04–20.18, t=4.01, P<0.001).Conclusion: The level of PGE2 in tears is positively correlated with OSDI score, but has no significant correlation with BUT, the CFLS score and Schirmer I test.