| Diabetes mellitus is a global disease. According to WHO, there are about 120 million diabetes mellitus patients, and the number will be doubled in 2005. More than 2% Chinese people suffer this disease. Diabetes mellitus are the reason for many eye disorders. Although lots of researches on diabetic retinopathy and cataract have been done, studies on diabetic keratopathy are far less. A great deal of dysfunctions have been detected in patients with diabetes mellitus, such as recurrent corneal ulcer, persistent corneal epithelium defects, epithelial oedema and impairment of corneal sensitivity. Slitlamp biomicroscopy and specula microscopy were often used to diagnose corneal disorder, but they can't provide layer-by -layer images of the cornea and can't perform the etiological diagnoses because of their low magnification and differentiation. Laser scanning confocal microscopy is a new kind of optical microscopy, which can scan and examine living human eyes real-timely, continually, non-invasively and in 3-division, and observe the dynamic changing of the cornea at the cellular level, and can also supply the directed and exacted measure on sublayer thickness, so it is possible to study the cornea at cellular level.Diabetes can affect each layer of the cornea, so the restudy on diabetic keratopathy will play a significantly role. Some of corneal disease, such as Acanthamoeba Keratitis, Herpes Simplex Keratits and Cornral Degeneration has ever been studied with confocal microscopy by foreign doctors, but studies on diabetic keratopathy were less reported. Inland researches on diabetic keratopathy restricts within animal trial and organ cultured cornea. Many reports are about endothelia cell of diabetic keratopathy, but more morphologic abnormalities were detected in epithelium layer, Bowman layer, stroma, Descemet membrane of thepatient suffering for diabetic keratopathy. The Z-SCAN precision of confocal microscopy is 8 μ m, so it can observe the morphologic changes of each corneal layer of diabetes patients. At the same time, the reason for diabetic keratopathy and the method to prevent the complications can be reached. The study by confocal microscopy will supply the gap of the diabetic research for other corneal layers except endothelia layer. This study evaluates the corneal morphologic characteristics of patients with and without diabetes, analyzes the basal cells of the epithelium, Bownan's layer, anterior stroma, mid-stroma, posterior stroma and endothelium respectively, and discusses the mechanism and histological foundation of diabetic keratopathy at cellular level.146 eyes of 120 patients in our center during the period of Oct-2003 to Oct-2004, who were diagnosed as type 2 diabetes, were chosen as the study group of diabetes. Other 36 eyes of 36 cataract patients comprised the control group to be compared with the study group. On the basis of indirect ophthalmoscopic examination and fluorescein angiography, the study group was divided into three sub-groups according to the stage of retinopathy: non-diabetic retinopathy(NDRP), non-proliferative diabetic retinopathy(NPDR) and proliferative diabetic retinopathy(PDR). All the eyes were examined with confocal microscopy and all the scans were reviewed and analyzed. Results are as following:1. Neurotropic corneal epithelial keratopathy and microdots can been observed with confocal microdcopy.2. Corneal branch nerve fibre density of subbasal nerve plexus decreased indiabetic group compared with control group, that is significant to statistics. The nerve fibre density decreasing can only be seen in the PDR sub-group, while NDRP and NPDR sub-groups changed less. There were no obviously differences among control group, NDRP and NPDR sub-groups. The proportion of patients in diabetes group with abnormal -morphology nerve fibres in mid-stroma was higher than thatin control group.3. Compared with control group, the cell density of anterior stroma in the PDR sub-group is lower, whereas the cell density of posterior stroma in both NPDR and PDR group is lower.4. Morphologic characteristics of descemet's membrane in type 2 diabete is shown as particular micro-fold line.5. There is no siginificant differences of the endothelia cell density between diabetic group and control group, but the cells of endothelium in diabetic group demonstrated a significantly higher coefiicient of variation, and a decreased percentage of hexagonal cells compared to those in control group. As the development of diabetic retinopathy, the percentage of hexagonal cells decreased. The difference was statistictically significant. Guttae was observed in 5 patients of NDRP sub-group.6. Compared with the control group, the diabetic group showed decreased epithelia thickness. The difference was statistictically significant. The epithelia thickness became thinness with the development of diabetic retinopathy, but the difference was insignificant.7. The density of endothelia cells negatively correlated with HbAIc, and didn't correlated with Blood creatinine, Blood urea nitrogen, High density lipoprotein, Low density lipoprotein, Cholesterol, and Triglyceride.Conclusions:1 ? Laser scanning confocal microscopy is a new kind of optical microscopy, which can scan and examine living human eyes real-timely, continually, non-invasively and in 3-division, and observe the dynamic changing of the cornea at the cellular level, so it provide a new technology in the research of diabetic keratopathy.2. Diabetes can affect each layer of the cornea. Morphologic abnormalities... |
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