Rosenberg M E, Tervo T M, Immonen I J, Müller L J, Grönhagen-Riska C, Vesaluoma M H
Department of Ophthalmology, University of Helsinki, Finland.
Invest Ophthalmol Vis Sci. 2000 Sep;41(10):2915-21.
Corneal wound healing is impaired in diabetic cornea. The purpose of this study was to examine patients with type 1 diabetes mellitus for changes in corneal morphology and to correlate corneal sensitivity, subbasal nerve morphology, and degree of polyneuropathy with each other.
Forty-four eyes of 23 patients with diabetes and nine control eyes were included. Corneal sensitivity was tested with a Cochet-Bonnet esthesiometer (Luneau, Paris, France), and corneal morphology and epithelial and corneal thickness were determined by in vivo confocal microscopy. The density of subbasal nerves was evaluated by calculating the number of long subbasal nerve fiber bundles per confocal microscopic field. The degree of polyneuropathy was evaluated using the clinical part of the Michigan Neuropathy Screening Instrument (MNSI) classification, and retinopathy was evaluated using fundus photographs.
A reduction of long nerve fiber bundles per image was noted to have occurred already in patients with mild to moderate neuropathy, but corneal mechanical sensitivity was reduced only in patients with severe neuropathy. Compared with control subjects the corneal thickness was increased in patients with diabetes without neuropathy. The epithelium of patients with diabetes with severe neuropathy was significantly thinner than that of patients with diabetes without neuropathy.
Confocal microscopy appears to allow early detection of beginning neuropathy, because decreases in nerve fiber bundle counts precede impairment of corneal sensitivity. Apparently, the cornea becomes thicker in a relatively early stage of diabetes but does not further change with the degree of neuropathy. A reduction in neurotrophic stimuli in severe neuropathy may induce a thin epithelium that may lead to recurrent erosions.
糖尿病患者的角膜伤口愈合受损。本研究旨在检查1型糖尿病患者的角膜形态变化，并将角膜敏感性、基底膜下神经形态和多发性神经病变程度相互关联。
纳入23例糖尿病患者的44只眼和9只对照眼。使用Cochet-Bonnet触觉计（法国巴黎Luneau公司）测试角膜敏感性，通过活体共聚焦显微镜测定角膜形态、上皮厚度和角膜厚度。通过计算每个共聚焦显微镜视野中长基底膜下神经纤维束的数量来评估基底膜下神经的密度。使用密歇根神经病变筛查仪器（MNSI）分类的临床部分评估多发性神经病变的程度，使用眼底照片评估视网膜病变。
在轻度至中度神经病变患者中，已观察到每个图像中长神经纤维束减少，但仅在重度神经病变患者中角膜机械敏感性降低。与对照受试者相比，无神经病变的糖尿病患者角膜厚度增加。重度神经病变的糖尿病患者的上皮明显比无神经病变的糖尿病患者薄。
共聚焦显微镜似乎能够早期检测出开始的神经病变，因为神经纤维束数量的减少先于角膜敏感性受损。显然，在糖尿病相对早期阶段角膜会变厚，但不会随着神经病变程度进一步变化。重度神经病变中神经营养刺激的减少可能会导致上皮变薄，这可能会导致复发性糜烂。
