Progress of application of adaptive optics in ophthalmology / 中华实验眼科杂志

Adaptive optics (AO) can measure and correct wavefront aberrations in real time, which enables the optical system to adapt to external changes and maintain excellent optical performance, and has been gradually paid attention in the field of ophthalmology.AO technology can carry out optometry according to wavefront aberrations to improve the efficiency and accuracy of subjective and objective refraction, eliminate the influence of ocular aberrations on retinal imaging, provide more accurate data for the evaluation of optic nerve function, improve the effectiveness of visual perception training and provide vision care and treatment for special people, as well as simulate and predict postoperative visual outcome and give personalized schemes for refractive surgery and intraocular lens implantation.Moreover, AO combined with optical coherence tomography, optical scanning laser ophthalmoscope, and confocal scanning laser ophthalmoscope, can realize fundus imaging and retinal vascular imaging in real time, provide better sensitivity and resolution of retinal detection, distinguish fine details of retinal vessels and cone cells, and characterize retinal pigment epithelium topology and deformation, the application of which in posterior segment laser surgery, glaucoma diagnosis and follow-up, color blindness and retinal physiological activity research has been attracting attention.In this article, the principle and application of AO in ophthalmology were briefly reviewed.

Rosacea Subtypes Visually and Optically Distinct When Viewed with Parallel-Polarized Imaging Technique

BACKGROUND: Parallel-polarized light (PPL) photography evaluates skin characteristics by analyzing light reflections from the skin surface. OBJECTIVE: The aim of this study was to determine the significance of quantitative analysis of PPL images in rosacea patients, and to provide a new objective evaluation method for use in clinical research and practice. METHODS: A total of 49 rosacea patients were enrolled. PPL images using green and white light emitting diodes (LEDs) were taken of the lesion and an adjacent normal area. The values from the PPL images were converted to CIELAB coordinates: L* corresponding to the brightness, a* to the red and green intensities, and b* to the yellow and blue intensities. RESULTS: A standard grading system showed negative correlations with L* (r=−0.67862, p=0.0108) and b* (r=−0.67862, p=0.0108), and a positive correlation with a* (r=0.64194, p=0.0180) with the green LEDs for papulopustular rosacea (PPR) types. The xerosis severity scale showed a positive correlation with L* (r=0.36709, p=0.0276) and a negative correlation with b* (r=−0.33068, p=0.0489) with the white LEDs for erythematotelangiectatic rosacea (ETR) types. In the ETR types, there was brighter lesional and normal skin with white LEDs and a higher score on the xerosis severity scale than the PPR types. CONCLUSION: This technique using PPL images is applicable to the quantitative and objective assessment of rosacea in clinical settings. In addition, the two main subtypes of ETR and PPR are distinct entities visually and optically.

Visual optics under the wavefront perspective / Óptica visual sob a perspectiva das frentes de onda

Some intriguing concepts of visual optics cannot be explained by ray tracing. However, they can be clarified using wavefront formalism. Its main advantage is in the use of the concept of vergence, which is very helpful in interpreting the optical phenomena involved in the neutralization of the ametropias. In this line of thinking, the major role of a lens is in the creation of a new light source (the image point) that orientates the refracted waves. Once the nature and position of this source is known, one can easily predict the behavior of the wavefronts. The formalism also allows for an easier understanding on how wavefronts relate to light rays and on how algebraic signs are assigned to optical distances.

Alguns conceitos intrigantes da óptica visual não podem ser explicados pelo traçado dos raios luminosos. Entretanto, eles podem ser esclarecidos através do formalismo da frente de onda. A vantagem do mesmo está no uso do conceito de vergência, que facilita o entendimento dos fenômenos ópticos envolvidos na neutralização das ametropias. Nessa linha de raciocínio, a principal função de uma lente é o de criar de uma nova fonte de luz - o ponto de imagem - que orienta as ondas refratadas. Conhecendo-se a natureza e a posição dessa fonte pode-se facilmente prever o comportamento das frentes de onda. Este formalismo também ajuda a compreensão de como as frentes de onda se relacionam com os raios de luz e como os sinais algébricos são atribuídos às distâncias ópticas.

Lentes progressivas: análise dos campos intermediário e de perto por deflexometria / Progressive addition lenses: analysis of intermediate and near vision zones by deflectometry

OBJETIVO: Avaliar por deflexometria as diferentes regiões das lentes progressivas e determinar as áreas dos campos de visão intermediário e de perto. MÉTODOS: Foram incluídas vinte e duas lentes progressivas com poder +1,00 DE para longe e duas adições diferentes (adição 1,00 e 2,00, 11 de cada). Mediram-se as áreas dos campos intermediário e de perto entre as isoastigmáticas de 0,5 DC. RESULTADOS: Encontraram-se diferenças significativas entre as áreas dos campos intermediário e de perto das lentes estudadas. Entre a área do campo intermediário e a adição observou-se correlação inversa; entre a área do campo intermediário e a extensão vertical do corredor encontrou-se correlação direta. CONCLUSÃO: Com esses dados permitem-se recomendar as lentes de acordo com o campo de maior necessidade visual de cada usuário.

PURPOSE: To determine near and intermediate vision areas of progressive addition lenses by means of a deflectometer. METHODS: Twenty-two progressive addition lenses with +1.00 SD far power and two different additions (add 1.00 and 2.00; eleven subjects in each addition) were studied. Near and intermediate vision areas within 0.50 CD isoastigmatic lines were determined. RESULTS: There are significant differences between near and intermediate vision areas of the studied lenses. There is also an inverse correlation between the addition and intermediate areas as well as direct relation between the vertical length of the corridor and its area. CONCLUSION: Based on those findings, progressive addition lenses can be selected to suit the wearer's visual requirements.

Estudo do grau de polarização linear em lesões de pele irradiadas com laser durante o processo de cicatrização / Study of linear polarization degree in skin lesions irradiated with laser during the healing process

Introdução: Alguns dos fatores determinantes na resposta fotobiológica da terapia laser em baixa intensidade são o estado fisiológico do tecido e as características ópticas do feixe, como a polarização de seu campo elétrico. Objetivos: Investigaram-se o grau e a preservação da polarização linear em amostras de pele de rato sadia e lesionada. Métodos: Criolesões foram realizadas no dorso de ratos e tratadas por quatro dias com 1J/cm2. O campo elétrico do laser foi alinhado a 0º e a 90º em relação à coluna vertebral dos animais. Resultados: A polarização foi mantida nas camadas superficiais da pele, sendo mais preservada na pele queimada. Durante o processo cicatricial, a lesão cujo campo elétrico foi alinhado a 0º em relação à coluna vertebral mostrou um grau de polarização semelhante àquele da pele sadia. Conclusões: O processo de reparação da pele foi influenciado pela polarização linear do feixe laser de He-Ne.

Introduction: The physiological conditions of tissue and optical characteristics of beam, like electric polarization, are some of the determining factors in the photobiological response of low intensity laser therapy. Objectives: The degree and preservation of linear polarization in samples of healthy and injured rat skin were investigated. Methods: Cryolesions were created in the lower back of rats and treated for four days with 1J/cm2. The laser electric was aligned in 0º and 90º to the backbone of the animals. Results: The polarization was maintained in the superficial layers of the skin, being better preserved in burned skin. During the wound healing, the lesion whose electric was aligned parallel to the spine showed a degree of bias similar to that of healthy skin. Conclusions: The repair process of skin was influenced by linear polarization of He-Ne laser beam.

Jean-Paul Marat: Médico, científico y revolucionario / Jean-Paul Marat: Physician, scientist and revolutionary

Physician, scientist and revolutionary are the biographical aspects that had better summarize the life of Jean-Paul Marat (1743-1793). Due to the role that he played during the French Revolution, his work as a physician and scientist, prior to the events of l789, was forgotten. Marat made important contributions in the area of optics and electricity reflected in numerous publications, as well as translating Newton's Opticks (1787). Well known for his radical and aggressive ideas, his political vocation led him to embrace the revolutionary cause after the events of the Bastille. His figure was not indifferent to his contemporaries; although considered a hero by the poorest citizens, aristocrats and bourgeois considered him a cruel extremist. During the last years of his life, he suffered a cutaneous disease, the diagnosis of which is still a matter of controversy. Proposed diagnoses include eczema, seborrheic dermatitis, scabies and dermatitis herpetica, among others. Marat was assassinated by Charlotte Corday in 1793, becoming a martyr for some segments of the society that worshiped his memory. He was a man with a complex and curious personality whose figure and legacy are still a matter of discussion.