Weston B C, Bourne W M, Polse K A, Hodge D O
Department of Ophthalmology, Mayo Clinic, Rochester, Minnesota 55905.
Invest Ophthalmol Vis Sci. 1995 Mar;36(3):586-95.
To assess the effects of diabetes mellitus on corneal structure and function.
The authors measured endothelial permeability to fluorescein and corneal deswelling for 7.5 hours after 2 hours of hypoxic contact lens wear in 20 patients with diabetes who had nonproliferative retinopathy and 21 age-matched control subjects. Central corneal endothelial photographs were also taken. Corneal deswelling rates, expressed as percent recovery per hour (PRPH), and open eye steady state (OESS) thickness were estimated by nonlinear regression techniques.
The OESS thickness was greater in patients with diabetes than in controls (562 +/- 35 microns versus 539 +/- 24 microns, P = 0.02). During hypoxia, the diabetic corneas swelled less (7.7% +/- 1.8% versus 9.9% +/- 1.6%, P < 0.001) and had less endothelial permeability (3.55 +/- 0.83 x 10(-4) cm/min versus 4.14 +/- 0.68 x 10(-4) cm/min, P = 0.02) than the controls. During normoxia after contact lens removal, however, diabetic and control corneas had similar deswelling rates and permeabilities. Corneal autofluorescence was increased in the patients with diabetes (8.1 +/- 3.1 versus 6.0 +/- 1.9 ng/ml fluorescein equivalents, P = .005). The endothelial cells of the two groups were morphologically similar. Within the group with diabetes, however, those with moderate nonproliferative retinopathy had larger coefficients of variation of cell area and smaller percentages of hexagonal cells than those with mild nonproliferative retinopathy.
Although the diabetic corneas were thicker and more autofluorescent than control corneas, during hypoxia they swelled less and had decreased endothelial permeability. During normoxia, however, no difference was found in endothelial permeability or deswelling rate. The effects of diabetes on endothelial cell morphologic features appear to be related to the severity of the diabetes.
评估糖尿病对角膜结构和功能的影响。
作者测量了20例患有非增殖性视网膜病变的糖尿病患者和21例年龄匹配的对照受试者在缺氧隐形眼镜佩戴2小时后7.5小时内的内皮细胞对荧光素的通透性和角膜消肿情况。还拍摄了中央角膜内皮照片。通过非线性回归技术估计角膜消肿率，以每小时恢复百分比（PRPH）表示，以及睁眼稳态（OESS）厚度。
糖尿病患者的OESS厚度大于对照组（562±35微米对539±24微米，P = 0.02）。在缺氧期间，糖尿病角膜肿胀程度较小（7.7%±1.8%对9.9%±1.6%，P <0.001），内皮细胞通透性低于对照组（3.55±0.83×10⁻⁴厘米/分钟对4.14±0.68×10⁻⁴厘米/分钟，P = 0.02）。然而，在摘除隐形眼镜后的常氧期间，糖尿病角膜和对照角膜的消肿率和通透性相似。糖尿病患者的角膜自发荧光增加（8.1±3.1对6.0±1.9纳克/毫升荧光素当量，P = 0.005）。两组的内皮细胞在形态上相似。然而，在糖尿病组中，患有中度非增殖性视网膜病变的患者比患有轻度非增殖性视网膜病变的患者具有更大的细胞面积变异系数和更小的六边形细胞百分比。
尽管糖尿病角膜比对照角膜更厚且自发荧光更强，但在缺氧期间它们肿胀程度较小且内皮细胞通透性降低。然而，在常氧期间，在内皮细胞通透性或消肿率方面未发现差异。糖尿病对内皮细胞形态特征的影响似乎与糖尿病的严重程度有关。
