Objective. We evaluated the histamine’s role in regulating the iris vasomotricity in rats, using as a research tool topical olopatadine, a selective H1 blocker, which is indicated for the treatment of allergic conjunctivitis and ranitidine, a selective H2 blocker mainly used for the treatment of peptic ulcer disease. Methods. Two groups of six Wistar rats anesthetized with ketamine 200 mg/kg body weight were used. They received distilled water in conjunctival instillations, initially and after 5 minutes, olopatadine 2.5 mmol/ l for the first group, respectively ranitidine 2.5 mmol/ l for the second group. The changes of the iris arteriolar and venular diameters were recorded. Results. Both olopatadine and ranitidine produced statistically significant iridal arteriolar vasoconstriction and ranitidine determined statistically significant venuloconstriction, while distilled water did not produce any statistically significant effect. Conclusions. There is a vasodilator histaminergic tone exerted through the histaminergic H1 and H2 receptors in the iris arterioles and, respectively, through the H2 receptors in the iridal venules. Olopatadine, a topical H1 antagonist used in the treatment of ocular allergies, may interfere with the humoral regulation of the iris arteriolar tone. Ranitidine, an H2 antagonist, decreased the diameter of the iris arterioles and venules, when administered topically in rats.

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Due to their anti-inflammatory, antiangiogenic and antiedematous properties, corticosteroids have been commonly used in the treatment of retinal diseases. Intravitreal administration of steroids offers the maximal drug efficacy and the lowest risk of systemic side effects. The authors report three cases of presumed sterile endophthalmitis induced by triamcinolone acetonide (TA) in three eyes with intermediate non-infectious uveitis. Each patient received a single intravitreal injection of TA of 4 mg. Because of the intense vitreous inflammatory reaction, retina examination and the optical coherence tomography could not be performed, although vitreous opacities were observed on the ocular ultrasound. The dense vitreous opacity is a defining factor, the anterior segment inflammation is mild to moderate and a hypopyon is present, which may be a sterile inflammatory reaction or the triamcinolone material itself. In cases of sterile endophthalmitis, the visual acuity increases progressively as the intraocular inflammation diminishes. Local treatment with topical antibiotics, prednisolone acetate and cycloplegic eyedrops is recommended to control the inflammatory reaction.

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The present paper is an introduction to this category of therapy, the injection of botulinum toxin into blepharospasm and, at the same time, an attempt to familiarize our readers with this concept. Our activity in this field started in 2014; the favorable results we have obtained since then have made us write this article.Abbreviations: BEB = Abnormal Benign Essential Blepharospasm, TXB = Botulinum Toxin