[The role of lipid metabolism and antioxidant system changes in the development of retinal vein occlusion].

PURPOSE: To compare changes in lipid metabolism and antioxidant status in patients with retinal vein occlusion (RVO) with that in patients with a history of ischemic stroke and in patients with no clinical manifestations of atherosclerosis. MATERIAL AND METHODS: A total of 111 patients were enrolled in the study. Group 1 included 80 patients with RVO and grade 2-3 stage II-III essential hypertension, group 2-11 patients with grade 3 stage III essential hypertension, high cardiovascular risk and a history of ischemic stroke. The control group included 20 patients with no clinical manifestations of atherosclerosis. All patients underwent a standard ophthalmic examination, fluorescent retinal angiography, lipid metabolism and redox system assessment. RESULTS: The levels of low-density lipoproteins (LDL) and cholinesterase were higher in study groups than in controls regardless the type of RVO. A statistically proven increase in oxidized LDL (oxLDL) was found in patients with complicated hypertension and ischemic RVO. A direct correlation was determined between the level of anti-oxLDL IgG and lipid peroxidation activity (LP) (R = 0.376; p = 0.136) as well as the levels of glutathione peroxidase (GPx) (R = 0.529; p = 0.029) and GPx per gram of hemoglobin (R = 0.543; p = 0.024) in patients with branch RVO. Redox system assessment showed a decrease of thiols and an increase of LP metabolites. CONCLUSION: The results demonstrated that retinal vein occlusions develop under disorders of lipid metabolism similar to those in patients with a history of ischemic stroke. The correlation between the level of anti-oxLDL IgG and LP points to the redox system involvement in the intricate pathogenesis of RVO.

[Morphological manifestations of systemic atherosclerosis found in fundus (experimental study)].

Results of angiography and morphology of 32 eyes (16 chinchilla rabbits) with experimental atherosclerosis are presented. N.N. Anichkov and S.S. Khalatova experimental hypercholesterolemia model (1912) was used. The animals were divided into the following groups: initial and advanced atherosclerosis, control group, follow-up 3 and 6 months. After 3 months progressive reduction of perfused retinal vessels and early degenerative changes of neurons and photoreceptors were found. In 6 months these changes became more significant and generalized. Due to ongoing small vessel reduction blood flow went to the major vessels and changed its distribution followed by ischemia of adjacent retina. No changes in choriocapillary layer and retinal pigment epithelium were found in any of groups studied.

[Ocular changes in systemic atherosclerosis].

Up-to-date aspects of ocular changes in systemic atherosclerosis are reviewed. At the present time despite of wide use of current methods of ocular blood circulation and retina examination there are no papers that allow to estimate dynamics of impairment of visual functions from different viewpoints (clinical, functional, blood flow, morphological etc.) in initial isolated ocular atherosclerosis. Etiology, pathogenesis and ideas about potential effect of systemic atherosclerosis on the eye are discussed. Features of blood flow in optic nerve head compared to retinal vessels are described. According to the last data correlation between the degree of reduction of a-wave of scotopic electroretinogram and deterioration of haemodynamic parameters exists.

[Role of vascular endothelial growth factor in the development of diabetic retinopathy in patients with type 1 diabetes mellitus].

The influence of vascular endothelial growth factor (VEGF) on the course of diabetic retinopathy (DR) was studied in 35 patients, including 11 males and 24 females, aged 21 to 56 years (mean 37 +/- 2.6 years) who had type 1 diabetes mellitus (DM) whose history was 14 to 40 years (mean 21.4 +/- 2.7 years). Tear and serum VEGF was examined by solid-phase enzyme-linked immunosorbent assay (ELISA), by using diagnostic Bender MedSystems (Austria) on a Stat Fax-2100 (USA). In the active phase of proliferative DR, the patients with type 1 DM were found to have the highest level of tear VEGF; when the process changed to a inactive phase, the content of this factor significantly reduced. There was a relationship between the tear level of VEGF and the degree of various manifestations of DR. There is an agreement of the tear and serum levels of VEGF in patients with different stages and manifestations of DR, which may be evidence for the single mechanism responsible for vascular endothelial damage in DM. There is a relationship between the presence of VEGF, the proliferative stage of DR, and diabetic nephropathy.