RESUMO
Inflammation is a defensive reaction and the most common pathological manifestation of dry eye.In addition,excessive inflammatory response is considered to be the most common pathogenic factor and main cause of dry eye.Currently,the active mechanism of anti-inflammatory drugs has been well-known,and topical antiinflammatory therapy for dry eye is exerting a role at certain extend.However,some adverse responses of these drugs are emerging during the treating procedure.Therefore,it is emphasized that a large sample size of and multicenter randomized-controlled clinical trial is needed to identify the different effects of various anti-inflammatory drugs for different types of dry eye diseases,which will offer a basis for standardized anti-inflammatory treatment for dry eye.
RESUMO
<p><b>BACKGROUND</b>Corneal neovascular leakage can lead to edema and secondary scarring. Previous studies have shown that pericytes play a key role in maturation of angiogenesis. The present studies investigate the relationship between vascular permeability and pericyte coverage of endothelial cells in rat corneal neovascular induced by alkali burns.</p><p><b>METHODS</b>Corneal neovascular vessels induced by alkali burns was performed in Sprague-Dawley rats. Corneas were excised on 1, 2, 3, 5, 7 and 10 days after cauterization. The vascular permeability rate was measured by the Evans blue method. The microvessel pericyte coverage index (MPI) was applied to quantify the pericyte coverage through double immunofluorescent staining of frozen sections of corneas with CD31 as the endothelial and alpha-smooth muscle actin (alpha-SMA) as the pericyte markers. The correlation between permeability rate and MPI was analyzed. Pericyte coverage was confirmed ultrastructually using transmission electron microscopy.</p><p><b>RESULTS</b>The vascular permeability rate was (1.14 +/- 0.17), (0.24 +/- 0.08), (0.29 +/- 0.16), (0.14 +/- 0.10), (0.09 +/- 0.06) and (0.05 +/- 0.04) microg x ml(-1) x mm(-2) respectively on 1, 2, 3, 5, 7 and 10 days after cauterization. The MPI was 0, 16.07%, 11.95%, 43.84%, 73.97% and 86.21% respectively at the above mentioned time points. The correlation coefficient between MPI and the permeability rate was -0.943 (P = 0.005).</p><p><b>CONCLUSIONS</b>Pericyte recruitment was significantly correlated with the permeability of corneal neovascularization induced by alkali burns in rats. Therapeutic strategies aiming at anti-leakage should be most effective if they promote pericytes proliferation in the course of corneal neovascularization.</p>