Purpose

To investigate clinical and inflammatory changes in the ocular surface of insulin-dependent type I diabetic patients.

Methods

Two hundred and nine eyes of 106 patients with diagnosis of type I diabetes were recruited in a prospective observational study. Ocular surface clinical assessment, corneal sensitivity and tear film stability tests were performed to evaluate ocular surface system function. Ocular Surface Disease Index (OSDI) questionnaire was administered to all enrolled subjects. Conjunctival impression cytology specimens were also collected to detect neuromediators and inflammatory molecules. Duration of disease, HbA1c levels and diabetic retinopathy stage were recorded.

Results

Corneal sensitivity assessed by Cochet-Bonnet esthesiometer was reduced in patients with more chronic disease, higher HbA1c levels and proliferative diabetic retinopathy. Tear break-up time (TBUT) was reduced in subjects with long-standing diabetes or with more severe retinopathy. OSDI questionnaire scores showed direct correlation with increased HbA1c values. Significant increase of NPY, STAT-5 and ICAM-1 was found in diabetic patients compared to healthy controls. A direct correlation between NPY concentration and ICAM-1 values in patients with type I diabetes was demonstrated.

Conclusions

Patients with long-standing type I diabetes showed chronic inflammation of the ocular surface, due to neurogenic dysregulation of para-inflammatory homeostatic mechanisms. These patients with ocular surface system failure complained of ocular discomfort but had modest reduction of corneal sensitivity and no signs of neurotrophic keratopathy. Disease duration, increased HbA1c levels and severe diabetic retinopathy appear the most critical factors.

中文翻译：

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眼表糖尿病：神经源性疾病？

目的

调查胰岛素依赖性I型糖尿病患者眼表的临床和炎症变化。

方法

在一项前瞻性观察研究中，招募了106例诊断为I型糖尿病的患者的299只眼。进行了眼表临床评估，角膜敏感性和泪膜稳定性测试，以评估眼表系统功能。眼表疾病指数（OSDI）调查表被管理给所有入选的受试者。还收集结膜印象细胞学标本以检测神经介质和炎症分子。记录病程，HbA1c水平和糖尿病性视网膜病变阶段。

结果

患有慢性疾病，HbA1c水平较高和增生性糖尿病性视网膜病变的患者，通过Cochet-Bonnet麻醉仪评估的角膜敏感性降低。患有长期糖尿病或更严重的视网膜病变的受试者的眼泪破裂时间（TBUT）减少。OSDI问卷评分显示与HbA1c值增加直接相关。与健康对照组相比，糖尿病患者发现NPY，STAT-5和ICAM-1显着增加。I型糖尿病患者的NPY浓度与ICAM-1值之间存在直接关系。

结论

长期存在的I型糖尿病患者由于准炎性稳态机制的神经源性失调而显示出眼表的慢性炎症。这些眼表系统衰竭的患者主诉眼部不适，但角膜敏感性适度降低，无神经营养性角膜病变的迹象。疾病持续时间，HbA1c水平升高和严重的糖尿病性视网膜病变是最关键的因素。