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Starting from previous studies showing that patients with cognitive deficit present neutral lipids (NLs) accumulation in cytoplasm of their peripheral blood mononuclear cells (PBMCs) and considering that there is epidemiological evidence linking age-related macular degeneration (AMD) to cognitive deficit, the first purpose of this study was to test whether neutral lipids also accumulated in PBMCs from AMD subjects. Moreover, the impact of statin use on AMD was explored and whether such use in AMD subjects was associated with NLs accumulation in PBMCs. The study was conducted on 222 subjects: 136 AMD (36 of which - 26.5% - using statins], 48 cognitive deficit (20 of which - 41.7% - using statins) and 38 healthy controls (4 of which -10.1% - using statins), AMD lesions were assessed from color fundus photographs. Mini-mental state examination (MMSE), demographics, lifestyle factors and medical history were collected at interview. MMSE score was categorized as normal (24-30), and impaired (24), NLs content was evaluated by oil red 0 (ORO) staining method. ORO determination showed that neutral lipids were generally absent or very low (score between 0 and 1) in healthy controls while most of PBMCs from cognitive deficit and AMD had ORO staining levels scoring 2-4. Post hoc analysis (Bonferroni) in a one-way ANOVA revealed that ORO score was significantly higher in cognitive deficit and AMD subjects compared to healthy controls and in cognitive deficit compared to AMD. Bonferroni-test also showed that AMD subjects had significantly lower total cholesterol (TC) levels compared to healthy controls while high density lipoprotein-cholesterol (HDL-C) did not reach statistical significance. The results also revealed a significant higher number of statin-users in AMD compared to healthy controls. Likewise when cognitive deficit vs healthy controls was analyzed, the number of statin users were found to be significant higher in cognitive deficit than in healthy controls. There were no significant differences in statin use between AMD and cognitive deficit. Compared to healthy controls, statin use in cognitive deficit and AMD groups was significantly associated with ORO scores of 2-4. This data supports the hypothesis that AMD and cognitive deficit share similar complex pathophysiology and risk factors including NLs accumulation in their PBMCs, although this does not necessarily imply that one disease causes the other. In addition, they provide further evidence that statin use may increase the risk of AMD.

To determine whether the fibrovascular proliferation observed in pterygium, may be, at least in part, mediated by an increased activity of cholesterol metabolism. The correlation between lipid metabolism and rate of growth was studied in human normal conjunctival (NCF) and primary pterygium fibroblasts (PFs) in primary culture. The expression of two proliferation markers (Ki-67 and p53) was evaluated by immunohistochemical staining techniques. Proliferation was evaluated by [ 3 H]thymidine incorporation and by immunohistochemical assays. Lipid metabolism was evaluated by 14 C-oleate incorporated into cholesterol esters as well as by oil red O staining. Moreover, the cultures of pterygium fibroblasts were supplemented with two antiproliferative drugs in order to confirm the effective alterations in cholesterol metabolism related to proliferation. Immunohistochemistry of frozen sections from primary pterygium demonstrated an increased staining in Ki-67 and p53 compared with staining observed in normal conjunctiva. A dramatically increased activity of intracellular cholesterol metabolism was demonstrated in pterygium fibroblasts obtained from four different patients. This finding was confirmed by the reduction of cholesterol metabolism in pterygium fibroblasts treated with antiproliferative drugs. Collectively, these data support the hypothesis that alterations of cholesterol metabolism are involved in the development of pterygia. This finding may represent a target of new therapeutic approaches for treatment and prevention of pterygium.

Coated pits (CPs) and coated vesicles (CVs) were investigated in the trabecular meshwork of man and rabbit. In both man and rabbit CPs and CVs appear to be randomly distributed throughout the trabecular tissue. CVs are located in the peripheral cytoplasm of the trabecular endothelial cells and show an average diameter of 0 . 16 micron. The ratio between the number of CPs and CVs ranges from 0 . 53 (rabbit) to 0 . 6 (man). The number of CPs and CVs is higher in rabbit than in man. Consequently, the overall CPs surface and CVs volume density estimates are higher in rabbits, where CPs represent about 1% of the cell surface and CVs account for about 0 . 4% of the cell cytoplasm. In man these percentages are 0 . 46 and 0 . 17%, respectively. No significant changes of CPs and CVs were found in rabbits with corticosteroid-induced ocular hypertension. However, changes in length of boundary membrane of CPs, though not statistically significant, were accompanied by proportional changes in CVs diameter.