Rudiment Study Of The Association Of Homocysteine Level In Tear And Plasma With Diabetic Ocular Surface Diseases And Diabetic Retinopathy

Objective: To investigate the association of Homocysteine (Hcy) level intear and plasma with diabetic ocular surface diseases and diabetic retinopathy, in order to discover the possible pathological mechanism of ocular complication of diabetes mellitus(DM) and quest for the way to prevent and treat it.Methods: The level of Hvy in tear and plasma of 25 patients with type 2DM and 25 non-diabetic controls(age and sex matched) were measured by high performance liquid chromatography with fluorescence detection(HPLC-FD). These 25 diabetic patients(50 eyes) and 25 non-diabetic controls(50 eyes) were examined by corneal sensitivity measurement, Schirmer's I test, tear film break up time (BUT) measurement, fluorescein staining of the cornea, rose Bengal staining of the conjunctiva. Slit-light microscope, ophthalmolscope were performed to them . All the patients and controls received fundus photography and fluorescein angiography. According to the results of fluorescein angiography. several markers were recorded: injection time of fluorescein sodium , arm-retina circulation time(A-RCT), retinal arteriovenous return time and retinal vein filling time. All the results were quantified , and analysed by SPSS 10.0 statistical analysis software.Results: Hcy existed in the tear of both diabetic patients and non-diabeticcontrols. The levels of Hcy in tear and plasma of diabetic patients were significantly higher than those of controls(P=0.000), and both of them increased with increasing severity of diabetic retinopathy in diabetic patients (Pearson Correlation r=0.715, 0.720, P=0.000). The corneal sensitivity , Schirmer's test values and BUT were significantly lower in the diabetic cases. The fluorescein staining and rose Bengal staining points increased in the diabetic group. The content of Hcy in the tear of diabetic patients had a negative correlation withcorneal sensitivity. The descent of corneal sensitivity in the diabetic group was more significant in the edge of the cornea. According to the results of FFA, both retinal arteriovenous return time and retinal vein filling time were lengthened in cases with DM, especially the retinal vein filling time. With the development of diabetic retinopathy, the retinal vein filling time was getting longer , and it was associated with plasma Hcy level( Pearson Correlation r=0.398, P=0.049) .Conclusion: The raise of Hcy level in tear and plasma of the patients withDM must be involved in the occurrence of diabetic ocular surface disease and retinopathy, and was a risk for diabetic corneal disease and retinopathy.