The effects of two longpass filters on visual performance / Efectos sobre el desempeño visual de dos filtros Longpass

PURPOSE: This study compared visual performance and optical properties of three filters. METHOD: Two groups of twenty adults were recruited: wearers of progressive addition lenses (PAL, 46-73 years) and wearers of single vision lenses (SVL, 26-55 years). Three spectacle filters (Hoya, Japan) were compared: clear control, Standard Drive (STD), and Professional Drive (PRO) lenses. Optical transmittance was measured by a Jasco V-650 spectrophotometer. Best corrected visual acuity (BCVA) was measured in photopic (BCVAphotopic) and mesopic (BCVAmesopic) conditions and under glare (BCVAglare). Photopic contrast sensitivity (CS) was also measured. RESULTS: The three longpass filters show cutoff at 426 ± 2 nm (STD/PRO) and 405 ± 2 nm (clear lens). BCVAglare improved with Drive filters compared to the clear one (p < 0.05) from 0.03 to -0.02 (STD) and to -0.01 (PRO) for PAL and from -0.08 to -0.12 (STD and PRO) for SVL. For PAL, BCVAmesopic improved from 0.15 to 0.12 (STD, p < 0.05) and 0.13 (PRO), while no substantial difference was observed for SVL. CS showed some improvements with Drive lenses at some angular frequencies between 6 and 18 cycles/deg, mainly for the PAL group. No BCVAphotopic differences were found. After testing all filters, each for two weeks, 79% (PAL) and 60% (SVL) of participants preferred Drive lenses. CONCLUSIONS: Drive lenses are found to maintain or improve some visual functions compared to the clear lens. The improvement of mesopic visual acuity, visual acuity under glare, and contrast sensitivity is mainly attributed to the reduction of intraocular light scattering as a consequence of the total light attenuation in the spectral range below the cutoff

OBJETIVO: Este estudio comparó el desempeño visual y las propiedades ópticas de tres filtros. MÉTODO: Se reclutaron dos grupos de veinte adultos: los que utilizaban lentes de adición progresiva (PAL,de 46 a 73 años), y los que utilizaban lentes monofocales (SVL, de 26 a 55 años). Se compararon tres filtros de gafas (Hoya, Japón): control claro, Standard Drive (STD), y Professional Drive (PRO). La transmitancia óptica se midió con un espectrofotómetro Jasco V-650. Se midió la agudeza visual mejor corregida (BCVA) en condiciones fotópicas (BCVAphotopic) y mesópicas (BCVAmesopic) y con deslumbramiento (BCVAglare). También se midió la sensibilidad al contraste fotópico (CS). RESULTADOS: Los tres filtros de amplio espectro reflejaron un punto de corte de 426 ± 2 nm (STD/PRO) y 405 ± 2 nm (lentes claras). BCVAglare mejoró con los filtros Drive en comparación con los filtros claros (p < 0,05) de 0,03 a -0,02 (STD) y -0,01 (PRO) para PAL, y de -0,08 a -0,12 (STD y PRO) para SVL. Para PAL, BCVAmesopic mejoró de 0,15 a 0,12 (STD, p < 0,05) y 0,13 (PRO), no encontrándose diferencia sustancial para SVL. CS reflejó algunas mejoras con las lentes Drive a ciertas frecuencias angulares entre 6 y 18 ciclos/deg, principalmente para el grupo PAL. No se encontraron diferencias para BCVAphotopic. Tras probar todos los filtros, cada uno de ellos durante dos semanas, el 79% (PAL) y el 60% (SVL) de los participantes prefirieron las lentes Drive. CONCLUSIONES: Se ha encontrado que las lentes Drive mantienen o mejoran ciertas funciones visuales en comparación con otras lentes claras. La mejora de la agudeza visual mesópica, la agudeza visual con sensibilidad de deslumbramiento y contraste se atribuye principalmente a la reducción de la dispersión de la luz intraocular, como consecuencia de la atenuación total de la luz en el rango espectral inferior al punto de corte

Testing feasibility of an accurate microscopic assessment of macrovesicular steatosis in liver allograft biopsies by smartphone add-on lenses.

Light microscopy is an essential tool in histological examination of tissue samples. However, the required equipment for a correct and rapid diagnosis is sometimes unavailable. Smartphones and mobile phone networks are widespread, and could be used for diagnostic imaging and telemedicine. Macrovesicular steatosis (MS) is a major risk factor for liver graft failure, and is only assessable by microscopic examination of a frozen tissue section. The aim of this study was to compare the microscopic assessment of MS in liver allograft biopsies by a smartphone with eyepiece adaptor (BLIPS device) to standard light microscopy. Forty liver graft biopsies were evaluated in transmitted light, using an Iphone 5s and 4 different mini-objective, add-on lenses. A significant correlation was reported between the two different approaches for graft MS assessment (Spearman's correlation coefficient: rs = 0.946; p < .001). Smartphone with eyepiece adaptor had similar discriminatory power to identify MS in liver grafts than standard light microscopy. Based on these findings, a smartphone integrated with a low-cost eyepiece adaptor can achieve adequate accuracy in the assessment of MS in liver graft, and could be used as an alternative to standard light microscope when unavailable.

[АComparative analysis of the magnitude of the distance and lens-induced objective accommodative response in patients with different refraction]. / Sravnitel'nyi analiz velichiny distantnogo i lensindutsirovannogo ob''ektivnogo akkomodatsionnogo otveta pri razlichnoi refraktsii.

AIM: To study the magnitude of objective accommodative response (OAR) with account to the method of image defocusing. The latter can be realized by bringing the object nearer to the eye or by adding a minus lens in front of the viewer. MATERIAL AND METHODS: We examined 63 patients (126 eyes) with different refraction aged from 7 to 31 years. All patients underwent a series of OAR measurements on WR-5100K Grand Seiko Binocular Open-Field Autorefkeratometer under different conditions, including negative spherical lenses of -3.0 D and -5.0 D, test optotypes corresponding to visual acuity of 0.2 and 0.7 and presented at a distance of 5 m, and a set of variably sized optotypes presented at a distance of 33 cm and 20 cm. RESULTS: A disparity was found between the magnitude of accommodative responses evoked through different means: placing a negative lens in front of the viewer while he/she looks into the distance or bringing the object closer to the eye. In almost all cases lens-induced responses were less pronounced than distance-induced. In all myopic children, accommodative lag was longer at near than at distance. Generally, in all groups, OAR to distant objects as well as responses to a 3.0 D accommodative task at near did not depend on the size of the object. There was an insignificant and statistically unreliable difference for objects placed 20 cm away (5.0 D accommodative task): OAR to a smaller font was stronger than that to a larger one. CONCLUSION: In children and adults with emmetropia, hyperopic children, and myopic adults, longer accommodative lags were characteristic of lens-induced responses. In children with myopia, longer lags were observed at near. Moreover, at near, OAR to a smaller font was stronger than that to a larger one.

Short-term comparison between extended depth-of-focus prototype contact lenses and a commercially-available center-near multifocal / Comparación a corto plazo entre las lentes prototipo de profundidad de campo extendidas y las lentes multifocales de visión central-próxima, comercialmente disponibles

Purpose: To compare the visual performance of prototype contact lenses which extend depthof-focus (EDOF) by deliberate manipulation of multiple higher-order spherical aberration terms and a commercially-available center-near lens (AIR OPTIX Aqua Multifocal, AOMF). Methods: This was a prospective, cross-over, randomized, single-masked (participant), shortterm clinical trial where 52 participants (age 45-70 years) were stratified as low, medium or high presbyopes and wore EDOF and AOMF on different days. Objective measures comprised high and low contrast visual acuity (HCVA/LCVA, log MAR), and contrast sensitivity (log units) at 6 m; HCVA at 70 cm, 50 cm and 40 cm and stereopsis (seconds of arc) at 40 cm. HCVA at 70 cm, 50 cm and 40 cm were measured as «comfortable acuity» rather than conventional resolution acuity. Subjective measures comprised clarity-of-vision and ghosting at distance, intermediate and near, overall vision satisfaction and ocular comfort (1-10 numeric rating scale) and lens purchase (yes/no response). Statistical analysis included repeated measures ANOVA, paired t-tests and McNemar’s test. Results: Significant differences between lens types were independent of strata (p ≥ 0.119). EDOF was significantly better than AOMF for HCVA at 40 cm (0.42 ± 0.18 vs. 0.48 ± 0.22, p = 0.024), stereopsis (98 ± 88 vs. 141 ± 114, p < 0.001), clarity-of-vision at intermediate (8.5 ± 1.6 vs. 7.7 ± 1.9, p = 0.006) and near (7.3 ± 2.5 vs. 6.2 ± 2.5, p = 0.005), lack-of-ghosting (p = 0.012), overall vision satisfaction (7.5 ± 1.7 vs. 6.4 ± 2.2, p < 0.001) and ocular comfort (9.0 ± 1.0 vs. 8.3 ± 1.7, p = 0.002). Significantly more participants chose to only-purchase EDOF (33% vs. 6%, p = 0.003).). There were no significant differences between lens types for any objective measure at 6 m or clarity-of-vision at distance (p ≥ 0.356). Conclusions: EDOF provides better intermediate and near vision performance in presbyopes than AOMF with no difference for distance vision during short-term wear (AU)

Objetivo: Comparar el rendimiento visual de prototipos de lentes de contacto con las de profundidad de campo extendida (EDOF), mediante la manipulación deliberada de múltiples aberraciones esféricas de alto orden y las lentes de visión simultánea centro-cerca comercialmente disponibles (AIR OPTIX Aqua Multifocal, AOMF). Métodos: Ensayo clínico prospectivo, transversal, aleatorizado, con máscara única (participante), y a corto plazo, en el que se estratificó la presbicia de 52 participantes (de edades comprendidas entre 45 y 70 años) como baja, media o alta; dichos participantes utilizaron lentes EDOF y AOMF en días diferentes. Las mediciones objetivas incluyeron la agudeza visual de alto y bajo contraste (HCVA/LCVA, log MAR), y la sensibilidad al contraste (unidades log) a 6 m, HCVA a 70 cm, 50 cm y 40 cm, y estereopsis (segundos de arco) a 40 cm. La HCVA a 70 cm, 50 cm y 40 cm se midió como «agudeza de confort» en lugar de la agudeza de resolución convencional. Las mediciones subjetivas incluyeron la claridad de visión y la visión fantasma (ghosting) a distancia, la satisfacción con la visión general intermedia y lejana, el confort ocular (escala de clasificación numérica de 1a 10) y la adquisición de lentes de contacto (respuesta sí/no). El análisis estadístico incluyó la prueba ANOVA con medidas repetidas, la prueba de t pareada, y la prueba de McNemar. Resultados: La significación de las diferencias entre los tipos de lentes fue independiente de los estratos (p ≥ 0,119). Los resultados de EDOF fueron considerablemente mejores que los de AOMF en cuanto a HCVA a 40 cm (0,42 ± 0,18 frente a 0,48 ± 0,22, p = 0,024), estereopsis (98 ± 88 frente a 141 ± 114, p < 0,001), claridad de visión intermedia (8,5 ± 16 frente a 7,7 ± 1,9, p = 0,006) y próxima (7,3 ± 2,5 frente a 6,2 ± 2,5, p = 0,005), ausencia de visión fantasma (p = 0,012), satisfacción con la visión general (7,5 ± 1,7 frente a 6,4 ± 2,2, p < 0,001) y confort ocular (9,0 ± 1,0 frente a 8,3 ± 1,7, p = 0,002). Un número considerable de participantes optó por adquirir únicamente EDOF (33% frente al 6%, p = 0,003). No se produjeron diferencias significativas entre los dos tipos de lentes en relación a las mediciones objetivas a 6 m, ni a la claridad de visión lejana (p ≥ 0,356). Conclusiones: Las lentes EDOF proporcionaron un mejor rendimiento de la visión intermedia y próxima en pacientes con presbicia que las lentes AOMF, sin que se produjeran diferencias en cuanto a visión lejana con el uso a corto plazo (AU)

¿Sirve para algo la lente de Goldman en el glaucoma por cierre angular? / Is the Goldman lens any good in angle-closure glaucoma?

No disponible

A clinician's guide to purchasing surgical loupes.

Magnification using loupes is expanding within dental professions. Loupes offer enhanced vision of fine detail and critical ergonomic advantages. To achieve the maximum benefit from loupes, the dental professional should consider key features at the time of purchase. Proper fitting and adjustment are essential elements in the successful use of loupes. Though more expensive than simple, diopter lenses, the inherent advantages of compound and prism telescopic loupes make them superior choices when dental magnification is being considered.

Comparison of low-vision reading with spectacle-mounted magnifiers.

Reading is the most common goal among persons with age-related macular degeneration and other retinal diseases that lead to macular loss, as well as the functional task most affected by the resulting central scotomas. This project determined whether reading ability is different when persons with macular loss read with a new hybrid-diffractive spectacle magnifier versus a refractive-aspheric spectacle magnifier and an aplanatic spectacle magnifier. After subjects completed a low-vision examination, we assigned them to groups that compared different types of spectacle magnifiers and assessed their reading acuity, speed, critical print size (print size large enough to provide a subject's best fluent reading), accuracy, and comprehension. Subjects completed visual analog scales to indicate their perceptions of satisfaction with reading, comfort with reading, and cosmesis (comfort with allowing others to see them read) and were asked which of the compared spectacle magnifiers they preferred for prescription. We subjected the data to paired t-tests to ascertain whether differences existed in subjects' reading ability and perceptions between the types of reading devices. Subjects' reading comprehension, perception of satisfaction, and perception of cosmesis were significantly better with the hybrid-diffractive lens than with the refractive-aspheric lens. Although subjects' critical print size was significantly better with the aplanatic lens than with the hybrid-diffractive lens, functional reading ability was not significantly different. More subjects preferred the hybrid-diffractive lenses for prescription. The hybrid-diffractive spectacle magnifiers are an important addition to the optical-device armamentarium for reading with low vision.

Improving nighttime mobility in persons with night blindness caused by retinitis pigmentosa: A comparison of two low-vision mobility devices.

This study compared the effectiveness of the ITT Night Vision Viewer with the Wide Angle Mobility Lamp (WAML) as low-vision mobility devices for people experiencing night blindness due to retinitis pigmentosa (RP). Both engineering bench testing and functional evaluations were used in the assessments. Engineering evaluations were conducted for (1) consistency of the manufacturer's specifications, (2) ergonomic characteristics, (3) modifications of devices, and (4) pedestrian safety issues. Twenty-seven patients with RP conducted rehabilitation evaluations with each device that included both clinical and functional tests. Both devices improved nighttime travel for people with night blindness as compared with nighttime travel with no device. Overall, the WAML provided better travel efficiency-equivalent to that measured in daytime. Recommendations have been developed on ergonomic factors for both devices. Although some participants preferred the ITT Night Vision Viewer, overall most participants performed better with the WAML.

[Working with magnification in dental medicine: useful or indispensible?]. / Le travail avec des loupes en médecine dentaire: utile ou indispensable?

In this article, the author describes the different types of magnifying-glasses which can be used in a dental practice. He informs about his own experience in using these glasses in his daily practice.

The anatomy of the surgical operating microscope and operating positions.

This article explores the current status of magnification and illumination in endodontic surgery. The basic operations of the operating microscope are described in detail and common misconceptions regarding its operation are explained. Finally, the various operating positions used in endodontic microsurgery are described and illustrated.