Diferentes concentraciones de mitomicina C en la prevención del haze en la queratectomía fotorrefractiva / Different concentrations of mitomycin C for haze prevention in photorefractive keratectomy

Objetivo: Evaluar la utilidad de dos concentraciones de mitomicina C para la prevención del haze en la queratectomía fotorrefractiva. Métodos: Se realizó un estudio experimental aleatorizado en 26 ojos de 17 pacientes con defectos miópicos. Los pacientes fueron asignados a dos grupos según las dosis de mitomicina C (0,02 por ciento grupo 1 y 0,002 por ciento grupo 2). La variable de respuesta principal fue la presencia de haze. Se buscó correlación entre la magnitud del haze con grado de ametropía tratada, profundidad de ablación, microscopia endotelial y resultados visuales y refractivos. Resultados: A los 6 meses la mayoría de los pacientes del grupo 1 no presentó haze (ocho ojos / 57 por ciento), y del grupo 2 mantuvieron haze 0,5 (6 ojos / 50 por ciento). En la ametropía severa el haze en el grupo 2 fue mayor que en el grupo 1 durante todo el posoperatorio, y se observó la mayor diferencia al sexto mes con 0,5 ± 0,4 vs. 1,5 ± 0,32. En ablaciones > 75 micras el grupo dos terminó con más haze que el uno, con 0,5 ± 0,44 vs. 1,75 ± 0,76. La agudeza visual sin corrección se vio más afectada en el grupo 2. No hubo daño endotelial en ningún grupo. Conclusión: La presencia de haze predomina en los casos tratados con dosis 0,002 por ciento de mitomicina C, comparada con la dosis 0,02 por ciento, aunque en este caso ambos grupos mantuvieron un resultado visual y refractivo adecuado y baja toxicidad endotelial.

Objective: Evaluate the usefulness of two concentrations of mitomycin C for haze prevention in photorefractive keratectomy. Methods: An experimental randomized study was conducted of 26 eyes of 17 patients with myopic defects. The patients were divided into two groups according to their mitomycin C doses (Group 1: 0.02 percent and Group 2: 0.002 percent). The main response variable was the presence of haze. Verification was performed of the correlation between haze magnitude and the degree of the ametropia treated, ablation depth, endothelial microscopy, and visual and refractive results. Results: At six months most patients in Group 1 did not have any haze (eight eyes / 57 percent), whereas 0.5 (6 eyes / 50 percent) in Group 2 still had haze. In severe ametropia, haze was larger in Group 2 than in Group 1 throughout the postoperative period, the greatest difference being observed in the sixth month with 0.5 ± 0.4 vs 1.5 ± 0.32. In ablations > 75 microns, Group 2 ended with more haze than Group 1, with 0.5 ± 0.44 vs 1.75 ± 0.76. Uncorrected visual acuity was more affected in Group 2. No endothelial damage occurred in either group. Conclusion: The presence of haze prevails in cases treated with 0.002 percent doses of mitomycin C, as compared with 0.02 percent doses, though in this case both groups maintained an appropriate visual and refractive result and low endothelial toxicity(AU)

Internal carotid artery thrombosis in COVID 19 / Trombosis de arteria carótida interna en COVID 19

Abstract Case description: 37-year-old female with PCR-RT swab for COVID-19 positive, with neurological manifestation as a result of internal carotid artery occlusion. Clinical findings: Nasal congestion and sneezing of 5 days duration; pulsatile headache in the left hemicranium 3 days prior to admission, with intensity 6/10 according to the visual analogue scale, accompanied by phosphenes, photophobia and diplopia; with subsequent developing right hemiparesis over a 26-hour period. Treatment and result: She was given medical management with oral antiplatelet agents and anticoagulants (subcutaneous and oral) during his hospitalization, it was not possible to perform thrombolysis and thrombectomy due to the high risk of complications. He was discharged at 14 days, without functional limitation, symmetrical strength in upper and lower limbs, bilateral visual acuity 20/20, denying headache. Clinical relevance: The case presented here describes a pattern in how data supporting an association between COVID-19 and stroke in young populations with or without typical vascular risk factors, sometimes with only mild respiratory symptoms, is increasing. Prospective studies are required to further evaluate this association, as well as anticoagulation studies to prevent these potentially life-threatening events.

Resumen Descripción del caso: Mujer de 37 años con hisopado PCR-RT para COVID-19 positivo, con manifestación neurológica por oclusión de la arteria carótida interna. Hallazgos clínicos: Congestión nasal y estornudos de 5 días de duración; cefalea pulsátil en hemicráneo izquierdo 3 días antes del ingreso, con intensidad 6/10 según la escala visual analógica, acompañada de fosfenos, fotofobia y diplopía; con posterior desarrollo de hemiparesia derecha durante un período de 26 horas. Tratamiento y resultado: Se le brindó manejo médico con antiagregantes plaquetarios orales y anticoagulantes (subcutáneos y orales) durante su internación, no fue posible realizar trombólisis y trombectomía por alto riesgo de complicaciones. Fue dado de alta a los 14 días, sin limitación funcional, fuerza simétrica en miembros superiores e inferiores, agudeza visual bilateral 20/20, negando cefalea. Relevancia clínica: Se describe un patrón que indica cómo están aumentando los datos que apoyan una asociación entre COVID-19 y el accidente cerebrovascular en poblaciones jóvenes con o sin factores de riesgo vascular típicos, a veces con solo síntomas respiratorios leves. Se requieren estudios prospectivos para evaluar más a fondo esta asociación, así como estudios de anticoagulación para prevenir estos eventos potencialmente mortales.

Effects of atracurium besylate on corneal endothelium of chickens: in vitro study / Avaliação dos efeitos do besilato de atracúrio no endotélio corneano de galinhas: estudo in vitro

The aim of this study was to investigate the acute effects of atracurium besylate on cellular damage in corneal endothelium of chickens. Twenty healthy chicken eyes were assigned to the following groups: Group 1 (G1), experimental group (n=10); and Group 2 (G2), control (n=10). Excised corneoscleral buttons were immediately placed on glass microscopy slides with endothelial region faced up. Corneal endothelium of eyes in G1 were covered with AB (0.2mL, 10mg/mL) for 3 min and then rinsed with balanced salt solution (BSS), while the corneal endothelium of eyes in G2 were covered with BBS for 3 min. Corneas from both groups were stained with alizarin red/trypan blue and visualized by light microscopy. Ten random photographs were taken from each cornea. The area of cellular damage was measured by software in all samples and cell loss of each group was averaged and compared. Endothelial area of denudation and Descemet's membrane exposure were higher in G1 than G2. In conclusion, atracurium besylate induced an acute damage on corneal endothelium of chickens.(AU)'

Objetivou-se avaliar os efeitos agudos do besilato de atracúrio sobre o endotélio corneano de galinhas. Vinte olhos saudáveis de galinhas foram aleatoriamente separados em dois grupos com 10 olhos cada, sendo G1 o grupo controle e G2 o grupo tratamento. Imediatamente após a excisão dos botões corneoesclerais estes foram colocados em lâminas de microscopia de vidro com o lado endotelial voltado para cima. No Grupo 1, o endotélio corneano foi recoberto com 0,2ml de besilato de atracúrio (10mg/ml) durante 3 minutos e depois lavado com solução salina balanceada. No Grupo 2, o endotélio corneano foi recoberto apenas com solução salina balanceada durante 3 min. As córneas de ambos os grupos foram coradas com vermelho de alizarina e azul de tripano e visualizadas com microscópio óptico. Foram obtidas dez fotografias aleatórias de cada amostra. As imagens foram analisadas e com auxílio de um software as áreas com ausência de células endoteliais calculadas. A perda celular endotelial foi significativamente maior no grupo tratamento comparativamente ao grupo controle. Com base nos resultados apresentados foi possível concluir que o besilato de atracúrio induziu dano agudo nas células do endotélio da córnea de galinhas.(AU)