ABSTRACT
ABSTRACT Purpose: This study aimed to use computational models for simulating the movement of respiratory droplets when assessing the efficacy of standard slit-lamp shield versus a new shield designed for increased clinician comfort as well as adequate protection. Methods: Simulations were performed using the commercial software Star-CCM+. Respiratory droplets were assumed to be 100% water in volume fraction with particle diameter distribution represented by a geometric mean of 74.4 (±1.5 standard deviation) μm over a 4-min duration. The total mass of respiratory droplets expelled from patients' mouths and droplet accumulation on the manikin were measured under the following three conditions: with no slit-lamp shield, using the standard slit-lamp shield, and using our new proposed shield. Results: The total accumulated water droplet mass (kilogram) and percentage of expelled mass accumulated on the shield under the three aforementioned conditions were as follows: 5.84e-10 kg (28% of the total weight of particle emitted that settled on the manikin), 9.14e-13 kg (0.045%), and 3.19e-13 (0.015%), respectively. The standard shield could shield off 99.83% of the particles that would otherwise be deposited on the manikin, which is comparable to 99.95% for the proposed design. Conclusion: Slit-lamp shields are effective infection control tools against respiratory droplets. The proposed shield showed comparable effectiveness compared with conventional slit-lamp shields, but with potentially enhanced ergonomics for ophthalmologists during slit-lamp examinations.
RESUMO Introdução: Os oftalmologistas têm alto risco de contrair a doença do Coronavírus-19 devido à proximidade com os pacientes durante os exames com lâmpada de fenda. Usamos um modelo de computação para avaliar a eficácia das proteções para lâmpadas de fenda e propusemos uma nova proteção ergonomicamente projetada. Métodos: As simulações foram realizadas no software comercial Star-CCM +. Os aerossóis de gotículas foram considerados 100% de água em fração de volume com distribuição de diâmetro de partícula representada por uma média geométrica de 74,4 ± 1,5 (desvio padrão) μm ao longo de uma duração de quatro minutos. A massa total de gotículas de água acumulada no manequim e a massa expelida pela boca do paciente foram medidas em três condições diferentes: 1) Sem protetor de lâmpada de fenda, 2) com protetor padrão, 3) Com o novo protetor proposto. Resultados: A massa total acumulada das gotas de água (kg) e a porcentagem da massa expelida acumulada no escudo para cada uma das respectivas condições foram; 1) 5,84e-10 kg (28% do peso total da partícula emitida que assentou no manequim), 2) 9,14e-13 kg (0,045%), 3,19e-13 (0,015%). O escudo padrão foi capaz de proteger 99,83% das partículas que, de outra forma, teriam se depositado no manequim, o que é semelhante a 99,95% para o projeto proposto. Conclusão: Protetores com lâmpada de fenda são ferramentas eficazes de controle de infecção contra gotículas respiratórias. O protetor proposto mostrou eficácia comparável em comparação com os protetores de lâmpada de fenda convencionais, mas potencialmente oferece uma melhor ergonomia para oftalmologistas durante o exame de lâmpada de fenda.
ABSTRACT
PURPOSE: Dermoscopy is a complementary examination of skin lesions, which allows the observation of anatomical features invisible to the naked eye. Its use increases the diagnostic accuracy of skin tumors. The development of polarized dermoscopy allowed the observation of deeper skin structures, without the need of skin contact. The purpose of this study was to present a low-cost prototype through the adaptation of polarized lenses on a slit lamp in order to assess anatomical aspects invisible to conventional biomicroscopy in eyelid lesions. METHODS: Twenty two eyelid lesions were documented using a prototype, compound of two polarizing filters, orthogonal to each other, adapted to a slit lamp with an integrated digital camera. Images of the eyelid lesions were also obtained with non-polarized biomicroscopy and with a portable dermatoscope, and were compared regarding anatomical aspects. RESULTS: Anatomical structures imperceptible to conventional ophthalmic examination were evidenced using the polarized lenses, demonstrating that this tool can be useful to the ophthalmologist when assessing eyelid lesions. We have obtained high-quality images of the lesions. The slit lamp provided higher magnification, better focus control and easier assessment of eyelid lesions than the portable dermatoscope. CONCLUSION: Ophthalmologists already use the slit lamp in their practice. The adaptation of polarized lenses to this device is a cost-effective, fast and non-invasive method that permits to improve the diagnostic accuracy of eyelid lesions, evidencing anatomical structures imperceptible to conventional ophthalmic examination.
Subject(s)
Skin Neoplasms , Slit Lamp , Humans , Dermoscopy , Cost-Benefit Analysis , Skin Neoplasms/diagnosis , Eyelids/pathologyABSTRACT
ABSTRACT Here, we describe the result of a Descemet's membrane endothelial keratoplasty for acute corneal hydrops in a 45-year-old female with keratoconus, who presented with severe visual loss in her OS. The patient's best-corrected visual acuity was 20/80 in the right eye and hand motion in the OS. Slit-lamp examination revealed an extensive tear of the Descemet's membrane and stromal corneal edema in the OS. We opted for Descemet membrane endothelial keratoplasty. Twelve months postoperatively, the patient had a best-corrected visual acuity of 20/50 in the OS.
RESUMO Trata-se de uma paciente do sexo feminino, de 45 anos, portadora de ceratocone, submetida a uma ceratoplastia endotelial com membrana Descemet após apresentar um quadro de perda de visão severa devido a uma hidrópsia corneana aguda no olho esquerdo. Inicialmente, a acuidade visual corrigida da paciente era de 20/80 no olho direito e de movimento de mãos no olho esquerdo. Após exame de biomicroscopia que detectou uma extensa rotura da membrana de Descemet e edema estromal, optamos por tratar esse caso com o ceratoplastia endotelial com membrana Descemet. Doze meses após o procedimento cirúrgico, percebeu-se uma melhora do edema corneano, não havia sinais de rejeição do botão óptico e a acuidade visual corrigida da paciente era de 20/50 no olho afetado.