Using a smartphone as a tool to measure compensatory and anomalous head positions / Uso do smartphone como ferramenta para medir a posição compensatória e anômala da cabeça

ABSTRACT Purpose: To describe a new method for measuring anomalous head positions by using a cell phone. Methods: The photo rotation feature of the iPhone® PHOTOS application was used. With the patient seated on a chair, a horizontal stripe was fixed on the wall in the background and a sagittal stripe was fixed on the seat. Photographs were obtained in the following views: front view (photographs A and B; with the head tilted over one shoulder) and upper axial view (photographs C and D; viewing the forehead and nose) (A and C are without camera rotation, and B and D are with camera rotation). A blank sheet of paper with two straight lines making a 32-degree angle was also photographed. Thirty examiners were instructed to measure the rotation required to align the reference points with the orthogonal axes. In order to set benchmarks to be compared with the measurements obtained by the examiners, blue lines were digitally added to the front and upper view photographs. Results: In the photograph of the sheet of paper (p=0.380 and a=5%), the observed values did not differ statistically from the known value of 32 degrees. Mean measurements were as follows: front view photograph A, 22.8 ± 2.77; front view B, 21.4 ± 1.61; upper view C, 19.6 ± 2.36; and upper view D, 20.1 ± 2.33 degrees. The mean difference in measurements for the front view photograph A was -1.88 (95% CI -2.88 to -0.88), front view B was -0.37 (95% CI -0.97 to 0.17), upper view C was 1.43 (95% CI 0.55 to 2.24), and upper view D was 1.87 (95% CI 1.02 to 2.77). Conclusion: The method used in this study for measuring anomalous head position is reproducible, with maximum variations for AHPs of 2.88 degrees around the X-axis and 2.77 degrees around the Y-axis.

RESUMO Objetivo: Descrever novo método de medida da posição anômala da cabeça (PAC) usando celular. Métodos: Foi utilizado o recurso de rotação de fotografias do aplicativo fotos do iPhone®. Com paciente em uma cadeira, foram fixadas duas faixas, uma horizontal, na parede ao fundo e outra sagital sobre o assento. Fotografias: frontal (1 A e 1 B), com a cabeça inclinada sobre um ombro, e superior (1 C e 1 D), visualizando testa e nariz. Também fotografada uma folha sulfite com duas retas desenhadas formando um ângulo de 32º. Trinta examinadores foram orientados a mensurar a rotação necessária para alinhar os pontos de referência com os eixos ortogonais. Para estabelecer medidas de referência a serem comparadas com aquelas obtidas pelos examinadores, foram acrescentadas digitalmente linhas azuis nas fotos frontal e superior. Resultados: Na foto da folha de papel (p=0,380 e a=5%), os valores observados não diferem estatisticamente do valor conhecido de 32º. Média das medidas: foto frontal 1A, 22,8 ± 2,77, frontal 1B, 21,4 ± 1,61, superior 1C, 19,6 ± 2,36 e superior 1D, 20,1±2,33. A média das diferenças das medidas na foto frontal 1A foi de -1,88 (IC 95% -2,88 a -0,88), frontal 1B de -0,37 (IC 95% -0,97 a 0,17), superior 1C de 1,43 (IC 95% 0,55 a 2,24) e superior 1D foi 1,87 (IC 95% 1,02 a 2,77). Conclusões: O método utilizado neste estudo para medida da posição anômala da cabeça é reprodutível e apresenta variação máxima de 2,88º nas posições anômalas da cabeça ao redor do eixo X e 2,77º do Y.

Aplicações clínicas do princípio de Scheimpflug na Oftalmologia / Clinical applications of the Scheimpflug principle in Ophthalmology

RESUMO Este artigo apresenta uma revisão dos princípios e das aplicações clínicas do princípio de Scheimpflug na área da imagiologia do segmento anterior. Ao disponibilizar uma imagem tridimensional do segmento anterior, esta tecnologia permite a caraterização da elevação e curvatura das superfícies anterior e posterior da córnea, o mapeamento paquimétrico, o cálculo do poder refrativo total da córnea e a biometria do segmento anterior. Na subespecialidade de cirurgia refrativa, esta abordagem melhora a capacidade de identificação de casos com risco de desenvolver ectasia, bem como de planeamento e de avaliação dos resultados dos procedimentos cirúrgicos. Recentemente, esta tecnologia foi introduzida na avaliação biomecânica in vivo da córnea e na cirurgia de catarata assistida por laser de femtossegundo.

ABSTRACT This article presents a review of the principles and clinical applications of the Scheimpflug principle in the anterior segment imaging. By providing a three-dimensional image of the anterior segment, this technology provides elevation and curvature data of the anterior and posterior surfaces of the cornea, pachymetric mapping, the total refractive power of the cornea and the anterior segment biometry. For the refractive surgery sub-specialty, this approach improves the ability to identify cases at risk of ectasia, as well as the planning and evaluation of the results of surgical procedures. Recently, this technology was introduced in corneal biomechanical in vivo evaluations and in femtosecond laser-assisted cataract surgery.

Comparison of the Progression of High- and Low-tension Glaucoma as Determined by Two Different Criteria

PURPOSE: To investigate and compare the progression of medically treated primary open angle glaucoma according to the baseline intraocular pressure (IOP). METHODS: This study included a total of 345 eyes from 345 patients (mean follow-up period, 4.5 years). Eyes were classified into either conventional normal tension glaucoma (cNTG, 21 mmHg) groups according to the conventional cut-off value of the IOP. Additionally, the median IOP (15 mmHg) was used to create two other groups (median NTG [mNTG] 15 mmHg). Using these values, 306, 39, 153, and 192 eyes were assigned to the cNTG, cHTG, mNTG, and mHTG groups, respectively. Glaucoma progression was determined either by optic disc/retinal nerve fiber layer photographs or serial visual field data. RESULTS: Mean reduction of IOP after medical treatment and of central corneal thickness was lower in the cNTG group, while the prevalence of disc hemorrhage and baseline visual field mean deviation did not differ between the cNTG and cHTG groups. A mean reduction in the IOP was observed after medical treatment, and central corneal thickness was lower in the mNTG group; disc hemorrhage was more frequent in the mNTG than in the mHTG group. Among the 345 analyzed eyes, 100 (29%) showed progression during the follow-up period. In the cHTG group, a higher baseline IOP (hazard ratio, 1.147; p = 0.024) was associated with glaucoma progression. Disc hemorrhage (hazard ratio, 15.533; p < 0.001) was also strongly associated with progression in the mNTG group. CONCLUSIONS: Baseline IOP was a significant risk factor for glaucoma progression in cHTG patients (10% of our total participants), while disc hemorrhage showed the strongest association with progression in the mNTG group, indicating that a cut-off value other than the conventional 21 mmHg is required to define true low-tension glaucoma in populations where NTG predominates among all glaucoma patients.

Analysis of angular reading distortions of photographic images / Análise das distorções em leituras angulares de imagens fotográficas

BACKGROUND: Although photogrammetry is a widespread technique in the health field, despite of the methodological efforts distortions in the angular readings of the images are common. OBJECTIVE: To measure the error of angular measurements in photo images with different digital resolutions in an object with pre-determined angles. METHODS: We used a rubber ball with 52 cm in circumference. The object was previously marked with angles of 10°, 30°, 60° and 90° degrees. The photographic records were performed with the focal axis of the camera perpendicular and three meters away from the object, without the use of optical zoom and a resolution of 3, 5 and 10 Megapixels (Mp). All photographic records were stored and a previously trained experimenter using the computer program ImageJ analyzed the angular values of each photo. The measurements were performed twice within a fifteen-days interval. Subsequently, we calculated the accuracy, relative error and error in degrees values, precision and the Intraclass Correlation Coefficient (ICC). RESULTS: When analyzing the angle of 10°, the average accuracy of measurements was higher for those records of 3 Mp resolution compared to 5 and 10 Mp resolutions. The ICC was considered excellent for all resolutions. With regards to the analyzed angles in photographic records, it was possible to verify that the 90-degree angle photographs were more accurate, had lower relative error and error in degrees, and were more precise, regardless of image resolution. CONCLUSION: The photographs records that were taken with a 3 Mp resolution provided great accuracy and precision measurements and lower errors values, suggesting to be the proper resolution to generate image of angles of 10º and 30º.

CONTEXTUALIZAÇÃO: A biofotogrametria é uma técnica difundida na área da saúde e, apesar dos cuidados metodológicos, há distorções nas leituras angulares das imagens fotográficas. OBJETIVO: Mensurar o erro das medidas angulares em imagens fotográficas com diferentes resoluções digitais em um objeto com ângulos pré-demarcados. MÉTODOS: Utilizou-se uma esfera de borracha com 52 cm de circunferência. O objeto foi previamente demarcado com ângulos de 10º, 30º, 60º e 90º, e os registros fotográficos foram realizados com o eixo focal da câmera a três metros de distância e perpendicular ao objeto, sem utilização de zoom óptico e com resolução de 3, 5 e 10 Megapixels (Mp). Todos os registros fotográficos foram armazenados, e os valores angulares foram analisados por um experimentador previamente treinado, utilizando o pro grama ImageJ. As aferições das medidas foram realizadas duas vezes, com intervalo de 15 dias entre elas. Posteriormente, foram calculados os valores de acurácia, erro relativo e em graus, precisão e Coeficiente de Correlação Intraclasse (ICC). RESULTADOS: Quando analisado o ângulo de 10º, a média da acurácia das medidas foi maior para os registros com resolução de 3 Mp em relação às resoluções de 5 e 10 Mp. O ICC foi considerado excelente para as três resoluções de imagem analisadas e, em relação aos ângulos analisados nos registros fotográficos, pôde-se verificar maior acurácia, menor erro relativo e em graus e maior precisão para o ângulo de 90º, independentemente da resolução da imagem. CONCLUSÃO: Os registros fotográficos realizados com a resolução de 3 Mp proporcionaram medidas de maiores valores de acurácia e precisão e menores valores de erro, sugerindo ser a resolução mais adequada para gerar imagem de ângulos de 10º e 30º.

Principles and practice of external digital photography in ophthalmology.

It is mandatory to incorporate clinical photography in an ophthalmic practice. Patient photographs are routinely used in teaching, presentations, documenting surgical outcomes and marketing. Standardized clinical photographs are part of an armamentarium for any ophthalmologist interested in enhancing his or her practice. Unfortunately, many clinicians still avoid taking patient photographs for want of basic knowledge or inclination. The ubiquitous presence of the digital camera and digital technology has made it extremely easy and affordable to take high-quality images. It is not compulsory to employ a professional photographer or invest in expensive equipment any longer for this purpose. Any ophthalmologist should be able to take clinical photographs in his/her office settings with minimal technical skill. The purpose of this article is to provide an ophthalmic surgeon with guidelines to achieve standardized photographic views for specific procedures, to achieve consistency, to help in pre-operative planning and to produce accurate pre-operative and post-operative comparisons, which will aid in self-improvement, patient education, medicolegal documentation and publications. This review also discusses editing, storage, patient consent, medicolegal issues and importance of maintenance of patient confidentiality.

Critérios para submissão de fotografias / Criteria for submitting photos

A fotografia dermatológica é complementar ao exame dermatológico. Sua função é ser um veículo de informação do conhecimento e sua qualidade depende da perícia do fotógrafo-dermatologista em registrar os elementos relevantes de uma cena. Por isso o dermatologista deve conhecer os princípios básicos da fotografia e os editores dos periódicos devem assegurar que os artigos tenham imagens de alta qualidade. Este artigo sugere critérios para melhorar a qualidade das fotos submetidas aos periódicos.

Dermatological photography is used as a supplement to dermatological examination with the function of providing additional knowledge and information. Its quality depends on the expertise of the photographer-dermatologist in recording the relevant elements present. Therefore, the dermatologist should know basic principles of photography and the journal editors should ensure that the articles have high-quality images. This article suggests criteria to improve the quality of photographs submitted to journals for publication.

Clinical Usefulness of Cervicogram as a Primary Screening Test for Cervical Neoplasia

The purpose of this study is to evaluate the clinical usefulness of the cervicogram as a primary screening test for cervical neoplasia. A total of 294 women who had undergone a cervicogram and a Pap test between January and July 2003, were selected. The diagnostic accuracy of the Pap test, cervicogram, and the Pap test combined with a cervicogram were compared with the histopathologic diagnosis. Among 294 women, the Pap test was negative in 130 cases and positive in 164 cases. Among patients with positive Pap test, cervicogram were negative in 101 cases (61.6%) and positive in 63 cases (38.4%). The diagnostic accuracy between cervicogram with positive Pap test and histology was as follows; sensitivity 44.9%, specificity 78.3%, positive predictive value 84.1%, negative predictive value 32.7%, false positive rate 15.9%, and false negative rate 67.3%. Although the adjunctive use of cervicogram with the Pap test in the initial screening of cervical neoplasia showed a higher specificity and higher positive predictive value compared to the Pap test alone, consideration in terms of lower sensitivity, lower positive predictive value, higher false positive rate and cost-effectiveness should be given in lieu of clinically applying cervicogram with the pap test as an initial screening test.

Cervigrafía empleando cervigramas impresos en papel

Mediante análisis matemático y observación directa, se demostró que empleando lupas la magnificación y resolución de cervigramas Impresos en Papel (CIP) fue igual a la de Cervigramas en Diapositiva proyectados en una pantalla. Se encontró que el empleo de CIP es más práctico y económico