The ocular surface bacterial contamination and its management in the prophylaxis of post cataract surgery endophthalmitis.

Objective: To investigate the recent pieces of evidence regarding the bacterial ocular surface contamination and its treatment in the prophylaxis of post-cataract surgery endophthalmitis. Methods: We conducted a literature research on the topic of interest and selected the most relevant data. Results: The studies reported a relatively high rate of positive conjunctival culture and the most frequently isolated organism was Coagulase negative Staphylococcus, which is also the most common etiological agent of the postoperative endophthalmitis. The bacterial ocular surface load is influenced by age, climate, associated diseases, topical and systemic medication. The use of povidone-iodine alone or in association with levofloxacin eyedrops as prophylactic method is effective in reducing the conjunctival bacterial contamination and consequently decreases the incidence of postoperative endophthalmitis. Conclusions: Based on the current pieces of evidence, adequate treatment of the bacterial ocular surface contamination prior to cataract surgery seems to be effective in preventing endophthalmitis after cataract surgery. Abbreviations: EU = European Union, Spp. = Species, HIV = Human Immunodeficiency Virus.

Experimental research in rats on the reactivity of new corneal blood vessels to adrenaline.

Aim: The purpose of this experimental study was to evaluate the existence of adrenergic receptors in ketamine-induced corneal blood vessels in rat pups. Methods: The study of corneal neovascularization motricity was performed on 45-day-old Wistar rats in which, starting from the 15th day of life, corneal blood vessels were obtained by injecting intraperitoneal ketamine at a dose of 150 mg/ kg body weight, a total of 5 successive doses. The examination of the neovascularization was done with the help of a Nikon stereomicroscope connected to a video camera and a computer, the total magnification being 400X. The reactivity of the new corneal blood vessels to the administration in conjunctival instillations of a 1.5 mmol/L adrenaline solution was tested. The parameters followed were represented by variations in the caliber of corneal blood vessels. The data were analyzed using Microsoft Office Excel. Results: Administration of distilled water did not produce statistically significant changes in corneal blood vessels, while adrenaline produced a statistically significant constriction of vascular diameter (p=0.01 at T9, p=0.004 at T10, p=0.019 at time T11 of examinations). Conclusions: The results showed that adrenaline produces vasoconstriction in the new corneal blood vessels, which allows us to assume that they contain α-adrenergic receptors. However, we cannot say that corneal pathological vessels do not contain ß2-type adrenergic receptors, because the effect of adrenaline may be an algebraic sum between vasoconstriction produced by stimulating α-adrenergic receptors and vasodilation produced by stimulating ß2-adrenergic receptors, but in which the vasodilating effect may be masked by the vasoconstrictor effect given by a higher density of α-adrenergic receptors. Abbreviations: A= adrenaline, DNM = non-measurable diameter, NA= noradrenaline, Std.Er.= Standard error.