Investigação oftalmológica pré-clínica do óleo essencial de Origanum vulgare L. Lamiaceae / Ophthalmological pre-clinical research about essential oil from the Origanum vulgare L. Lamiaceae

RESUMO Objetivo: Avaliar a irritação ocular aguda em coelhos, após a administração tópica de óleo essencial. Métodos: Para tanto, os animais foram divididos em três grupos, cada um com três coelhos, totalizando 6 olhos por grupo, e a diferença entre eles foi a concentração utilizada ( 1, 3 e 9%). Aplicou-se no saco conjuntival, de um dos olhos do animal, uma dose única de 0,1 ml do produto e o olho contralateral foi usado como controle. Analisou-se os efeitos causados pelo óleo essencial na conjuntiva, íris e córnea após 1, 24, 48, 72 horas e no final do sétimo dia após a aplicação tópica. As avaliações oftalmológicas foram feitas com o auxílio de um oftalmoscópio binocular indireto com e sem fluoresceína. As reações observadas foram graduadas segundo a escala de Draize. Foram realizados exames anatomopatológicos em todos os olhos estudados no final do experimento. Resultados: No grupo de animais submetidos à instilação ocular do óleo essencial a 1%, não se observou alterações. O tratamento com o óleo a 3% provocou alteração conjuntival no exame feito em 1 hora, o que foi reduzindo. A administração do óleo essencial a 9% induziu hiperemia conjuntival, não havendo qualquer alteração nos outros tempos de avaliação oftalmológica. Conclusão: A avaliação contribuiu para conhecer as alterações clínicas na superfície ocular. Desta forma, foi possível classificar o óleo a 1% como não irritante e nas concentrações de 3 e 9% como pouco irritante, tornando possível estudos clínicos, a fim de estabelecer o óleo como alternativa terapêutica em conjuntivites bacterianas.

ABSTRACT Objective: To evaluate acute eye irritation in rabbits following topical administration of essential oil. Methods: animals were divided into three groups, each containing three rabbits, with a total of 6 eyes per group. The difference between them was the concentration used (1, 3 and 9%). A single dose of 0.1 ml of the product was applied into the conjunctival sac of one eye of the animal, and the contralateral eye was used as control. The effects caused by the essential oil in the conjunctiva, iris and cornea were analyzed after 1, 24, 48 and 72 hours and at the end of the seventh day after topical application. Ophthalmologic evaluations were performed with the aid of a binocular indirect ophthalmoscope fluorescein and with and without the observed responses, before being graded according to the Draize scale. Pathological examinations were performed on all eyes studied at the end of the experiment. Results: in the group of animals subjected to the ocular instillation of 1% essential oil, there was no change. For treatment with 3% oil, conjunctival changes were found to be decreasing during the examination after 1 hour. Administration of the 9%essential oil induced conjunctival injection, without any change in the other ophthalmologic evaluation times. Conclusion: the evaluation contributed to meet the clinical changes in the ocular surface. Thus, it was possible to classify the oil at 1% as non-irritating and the concentration of 3% and 9 as mildly irritating, making it possible for clinical studies to establish the oil as an alternative therapy in bacterial conjunctivitis.

Methylene blue-related corneal edema and iris discoloration / Edema de córnea e descoloração de íris associados ao azul de metileno

ABSTRACT We report the case of a 70-year-old female patient who developed corneal edema and iris discoloration following the inadvertent use of 1% methylene blue instead of 0.025% trypan blue to stain the anterior capsule during cataract phacoemulsification surgery. Copious irrigation was performed upon realization of incorrect dye use. Corneal edema and iris discoloration developed during the early postoperative period and persisted at 24-months follow-up. However, keratoplasty was not required. The intracameral use of 1% methylene blue has a cytotoxic effect on the corneal endothelium and iris epithelium. Copious irrigation for at least 30 min using an anterior chamber maintainer may improve outcomes.

RESUMO Paciente do sexo feminino com 70 anos de idade desenvolveu edema da córnea e descoloração da íris após o uso inadvertido de 1% de azul de metileno em vez de 0,025% de azul tripano para corar a cápsula anterior do cristalino durante a cirurgia de catarata por facoemulsificação. Foi realizada irrigação abundante quando detectou-se que o corante incorreto tinha sido usado. Edema da córnea e descoloração íris que ocorreu no período pós-operatório precoce persistiu durante 24 meses de seguimento; no entanto, a ceratoplastia não foi necessária. O uso intracameral de 1% de azul de metileno tem efeitos citotóxicos sobre o endotélio da córnea e epitélio da íris. A irrigação abundante durante pelo menos 30 minutos, utilizando um mantenedor de câmara anterior pode resultar em um prognóstico melhor.

Benign prostatic hyperplasia: clinical treatment can complicate cataract surgery

PURPOSE: To investigate the effects of alpha-1 adrenergic receptor antagonists for the treatment of benign prostatic hyperplasia (BPH) regarding potential risks of complications in the setting of cataract surgery. AIM: To address recommendations, optimal control therapy, voiding symptoms and safety within the setting of cataract surgery. MATERIALS AND METHODS: A comprehensive literature review was performed using MEDLINE with MeSH terms and keywords "benign prostatic hyperplasia", "intraoperative floppy iris syndrome", "adrenergic alpha-antagonist" and "cataract surgery". In addition, reference lists from identified publications were reviewed to identify reports and studies of interest from 2001 to 2009. RESULTS: The first report of intraoperative floppy iris syndrome (IFIS) was observed during cataract surgery in patients taking systemic alpha-1 AR antagonists in 2005. It has been most commonly seen related to use of tamsulosin. Changes of medication and washout periods of up to 2 weeks have been attempted to reduce the risk of complications in the setting of cataract surgery. CONCLUSION: Patients under clinical treatment for BPH should be informed about potential risks of this drug class so that it can be discuss with their healthcare providers, in particular urologist and ophthalmologist, prior to cataract surgery.

Trans-differentiation of iris pigmented epithelial cells of Euphlyctis cyanophlyctis tadpoles into lens in vitro.

Meshed pigmented iris epithelium along with neural retina of tadpoles of the frog Euphlyctis cyanophlyctis were found to undergo dedifferentiation and subsequently transdifferentiate into lens in culture medium. During lag period, depigmentation (dedifferentiation) occurred in many cells. When culture became confluent 3-4 weeks after seeding tiny lens like structures differentiated from foci of cultured pigmented iris epithelium cells. The percentage of lens formation was higher in vitamin A treated cases. The culture system appears to be a suitable for investigating the changes occurred during trans-differentiation of pigmented epithelial cells into lens.

Heterogeneity of the mechanisms underlying activation of adenylatecyclase by endothelin-1 in rabbit and bovine iris sphincter and tracheal smooth muscles

In the bovine and rabbit iris sphincters and tracheas, endothelin-l [ET -1] activated adenylate cyclase [AC] in a concentration-dependent manner. The rate of cAMP formation decreased in the order, bovine iris sphincter > rabbit trachea > > rabbit iris sphincter > > bovine trachea. Maximal values for AC activation in bovine iris sphincter and rabbit trachea were 398% and 392% of basal activity respectively. Pretreatment with indomethacin [1 [micro]M], a cyclooxygenase inhibitor, virtually abolished the increase by ET-1 of cAMP levels in rabbit trachea and bovine trachea [96% reduction]. In the rabbit iris sphincter, indomethacin and nordihydroguairetic acid [NDGA] [1 [micro] M] lipoxygenase inhibitor, brought about 60 and 28% reduction of ET -1 response, respectively. Co-treatment with both eicosanoid inhibitors [1 [micro] M, each] eliminated the ET-1-evoked cAMP formation. Quinacrine [50 [micro] M], a phospholipase A2 [PLA2] inhibitor, attenuated cAMP production by ET -1 at a less prominent rate than that of indomethacin [38 to 70% reduction in cAMP increments]. At odds, in the bovine iris sphincter, the cAMP response was unaltered by all prostanoid inhibitors. Moreover, challenge with nicardipine [-a] Ca [2+] channel blocker, trifluoperazine -a calmodulin inhibitor, or staurosporine -a PKC inhibitor, had no significant effect on the responsiveness to ET -1, suggesting lack of mediators in the coupling of ET - receptors to AC system, in the bovine iris sphincter. In conclusion, activation of AC by ET -1 may represent a widespread phenomenon in smooth muscles. The mechanism whereby ET -1 elicits cAMP production is diverse and may include eicosanoids both from cyclooxygenase and lipoxygenase origins as mediators

Comparison of the anti-inflammatory effects of topically applied aspirin and indomethacin following photocoagulation of the rabbit iris

A comparative study of the inhibitory action of topically applied indomethacin and aspirin (1% (w/v) 2 h before and immediately after trauma, totaling 4 mg each) on myosis, increase in intraocular pressure and breakdown of the blood aqueous barrier was performed. Argon laser photocoagulation on the anterior surface of the left iris of pigmented rabbits, totaling 2,250 mJ, was used as traumatic stimulus. The untraumatized eye was used as a reference for measurements. Four groups of 10 animals each (control, photocoagulated plus indomethacin and photocoagulated plus aspirin) were studied. Both drugs similarly inhibited the increase in the total protein concentration in aqueous humor and in intraocular pressure at 10,20 and 40 min. Only aspirin showed some inhibitory action on the pupillary response 10 min after photocoagulation

Effect of apraclonidine hydrochloride on acute introacular pressure rise after argon laser iridotomy

To determine the effect of apraclonidine hydrochloride on the acute intraocular pressure (IOP) rise after argon laser iridotomy (ALI), a double-masked comparative study was carried out. Twenty-nine eyes (20 patients) with angle-closure glaucoma underwent ALI. Eighteen eyes were treated with apraclonidine, and the remainder received a placebo 1 hour before and immediately after ALI. The mean IOP increase in the apraclonidine group was lower than that in the placebo group at each postlaser interval (p or = 10 mmHg. However, that kind of IOP rise was not found in the apraclonidine group (0 out of 18 eyes) (p < 0.01). Ocular or systemic side effects were not found in a series of examinations in both groups. Therefore, apraclonidine proved to be effective in lowering the IOP rise after ALI.