The significance of changes in pupil size during straylight measurement and with varying environmental illuminance
ConclusionWe conclude that the illuminance of the examination room during straylight assessment does not affect the outcome in normal eyes. In fact, under mesopic and scotopic conditions, the luminance of the test field is so much higher than that of the room so that it determines the pupil size. Regardless of the lighting level, straylight measured in a laboratory, is valid for photopic pupils at an adaptation level corresponding with about 400 lux room illuminance.ResumenObjetivoEn este trabajo investigamos las condiciones de la pupila durante la medición de la dispersión lumínica, así como el efecto potencial que el...
Source: Journal of Optometry - July 10, 2018 Category: Opthalmology Source Type: research
Visual outcome of penetrating keratoplasty, deep anterior lamellar keratoplasty and Descemet membrane endothelial keratoplasty
ConclusionOverall, DMEK proved superior over PK and DALK in terms of quality of vision, with PK offering slightly better outcomes than DALK in most visual function parameters under evaluation.ResumenObjetivoSe diseñó un estudio en un único centro y transversal para evaluar y comparar la calidad de la visión subjetiva de los pacientes intervenidos de queratoplastia penetrante (QP), queratoplastia lamelar anterior profunda (QLAP) y queratoplastia endotelial de membrana de Descemet (DMEK).MétodosSe incluyó a cuarenta y seis pacientes previamente intervenidos de QP (22 ojos), QLAP (7 ojos) y DMEK (17 ojos). La evaluació...
Source: Journal of Optometry - July 10, 2018 Category: Opthalmology Source Type: research
Comparison of manual & automated analysis methods for corneal endothelial cell density measurements by specular microscopy
ConclusionOur findings show that automated analysis significantly overestimates ECD in the eyes with high polymegathism and/or large cell size, compared to the manual method. Therefore, we discourage reliance upon the fully-automated method alone to perform specular microscopy analysis, particularly if an accurate ECD value is imperative.ResumenObjetivoDeterminar la fiabilidad de la densidad celular endotelial corneal (ECD) obtenida mediante microscopio especular automático frente a métodos manuales validados y factores predictivos de la fiabilidad.MétodosSe capturaron imágenes nítidas de 94 controles y 106 ojos glauc...
Source: Journal of Optometry - July 10, 2018 Category: Opthalmology Source Type: research
Reply to: Central corneal thickness measurement with Cirrus HD-OCT and Topcon SP-3000P
Publication date: July–September 2018Source: Journal of Optometry, Volume 11, Issue 3Author(s): Jorge A. Calvo-Sanz (Source: Journal of Optometry)
Source: Journal of Optometry - July 10, 2018 Category: Opthalmology Source Type: research
Central corneal thickness measurement with Cirrus HD-OCT and Topcon SP-3000P
Publication date: July–September 2018Source: Journal of Optometry, Volume 11, Issue 3Author(s): Maddalena De Bernardo, Francesco Antonio Salzano, Nicola Rosa (Source: Journal of Optometry)
Source: Journal of Optometry - July 10, 2018 Category: Opthalmology Source Type: research
Tear instability importance, mechanisms, validity and reliability of assessment
ConclusionsFluorescein tear break up time assessments cannot be standardised and less-invasive methods are not yet standardised. Objective less-invasive and subjective fluorescein break up time tests do not appear to be measuring the same tear phenomena although both should be performed before other invasive procedures.ResumenObjetivoExaminar los factores que contribuyen a la estabilidad de la lágrima y a la validez y fiabilidad de los métodos utilizados para evaluar el tiempo de ruptura lagrimal, que forma parte esencial del examen de la estabilidad de la lágrima en los pacientes con ojo seco.MétodosRevisión y evalua...
Source: Journal of Optometry - July 5, 2018 Category: Opthalmology Source Type: research
Symmetry of peripheral retinal nonperfusion in diabetic retinopathy by ischemic index
ConclusionAsymmetrical retinopathy in diabetic patients is uncommon and additional pathological processes should be considered in the presence of asymmetric DR.ResumenObjetivoLa retinopatía diabética constituye la causa principal de ceguera entre los adultos en edad productiva en muchos países desarrollados. Afecta a los ojos bilateralmente, y por lo general se piensa que es simétrica, aunque existen pocos estudios que evalúen la simetría en esta situación. El objetivo del presente estudio fue evaluar la simetría de la cantidad de isquemia en la retina periférica en pacientes con retinopatía diabética.MétodosSe...
Source: Journal of Optometry - July 5, 2018 Category: Opthalmology Source Type: research
Validation of refraction and anterior segment parameters by a new multi-diagnostic platform (VX120)
ConclusionsThe VX120 provides consistent refraction and most anterior segment measurements in normal healthy eyes, with high levels of intra and inter-session repeatability.ResumenAntecedentesVX120 (Visionix Luneau, Francia) es una plataforma multi-diagnóstico novedosa que combina la auto-refracción basada en Hartmann–Shack, la topografía corneal mediante discos de Plácido, y las mediciones del segmento anterior realizadas mediante cámara de Scheimpflug. Analizamos la concordancia entre los diferentes parámetros medidos por VX120 con las técnicas aceptadas o de referencia, para probar si eran intercambiables, y ev...
Source: Journal of Optometry - July 5, 2018 Category: Opthalmology Source Type: research
Comparison of contrast sensitivity in β-thalassemia patients treated by deferoxamine or deferasirox
ConclusionsCS tests can detect visual disturbance in thalassemic patients before the impairment of visual acuity. It is suggested that CS tests be included in their regular eye examination.ResumenObjetivoComparar la sensibilidad de contraste (SC) en pacientes multitrasfundidos con β-talasemia y tratados con deferoxamina u Osveral.MétodosEn este estudio transversal, un total de 60 pacientes con β-talasemia (30 tratados con deferoxamina y 30 con deferasirox) fueron considerados como grupo de estudio, y 30 sujetos sanos pareados por edad y sexo fueron seleccionados como grupo control. A todos los sujetos se les realizó un...
Source: Journal of Optometry - July 5, 2018 Category: Opthalmology Source Type: research
Refractive error magnitude and variability: Relation to age
ConclusionsMean ocular refraction and refractive error distribution vary with age. The highest magnitude of myopia is found in young adults. Similar to prevalence, the severity of myopia also appears to have increased since 1931.ResumenObjetivoEstudiar la refracción ocular media (MOR) y el astigmatismo a lo largo del rango de la vida humana, y comparar la magnitud del error refractivo con estudios previos sobre poblaciones clínicas con rangos de edad amplios.MétodosPara este estudio descriptivo, se extrajeron de la base de datos Waterloo Eye Study (WatES) la edad del paciente, el error refractivo y el historial de cirug...
Source: Journal of Optometry - July 5, 2018 Category: Opthalmology Source Type: research
Accommodation and age-dependent eye model based on in vivo measurements
ConclusionsThe proposed eye model is able to predict changes in objective refraction and accommodation response. It has the potential to be a useful design and testing tool for devices (e.g. intraocular lenses or contact lenses) designed to correct the eye's optical errors.ResumenObjetivoDesarrollar un modelo flexible de ojo medio que incorpore los cambios en función de la edad y la acomodación en todos los parámetros ópticos, incluyendo el diámetro de pupila de entrada, en condiciones ambientales fotópicas y naturales.MétodosRecopilamos medidas retrospectivas in vivo de todos los parámetros ópticos, incluyendo el...
Source: Journal of Optometry - July 5, 2018 Category: Opthalmology Source Type: research
Is 25 Hz enough to accurately measure a dynamic change in the ocular accommodation?
ConclusionContrary to the previous findings, a dynamic accommodative response exhibited frequencies larger than 10 Hz. Stimulus direction and amplitude had no influence on the frequencies present in the dynamic response. Peak velocity and acceleration can be significantly underestimated when sampled at a lower rate. Taken as a whole, low sampling rate instruments can accurately estimate static accommodation, however, caution needs to be exercised when using them for dynamic accommodation.ResumenLa acomodación se registra a menudo a una tasa de muestreo baja, utilizando dispositivos tales como los autorrefractómetros...
Source: Journal of Optometry - July 5, 2018 Category: Opthalmology Source Type: research
Effect of phenylephrine on static and dynamic accommodation
ConclusionsThe mydriatic effect of the PHCl causes optical changes in the eye that can reduce the objective and subjective measurement of accommodation.ResumenObjetivoProbamos la hipótesis de que los cambios de la acomodación tras la instilación de Hidrocloruro de Fenilefrina (PHCl) observados en algunos estudios podrían estar originados por los cambios en la óptica.MétodosRealizamos dos experimentos para probar los efectos de PHCl sobre la acomodación estática y dinámica en 8 y 6 sujetos, respectivamente. Se registraron las mediciones objetivas de frente de onda de la respuesta acomodativa estática a un estímul...
Source: Journal of Optometry - July 5, 2018 Category: Opthalmology Source Type: research
Prevalence of esophoria in concussed patients
DiscussionNear esophoria was found in nearly one-third of this practice-based sample of concussed patients. Thus, it was more common than typically believed to be the case. Two proposed oculomotor-based mechanisms related to these symptomatic esophoric patients included phoria decompensation and excessive accommodative vergence.ResumenObjetivoEvaluar la prevalencia de la endoforia de cerca en pacientes con conmoción, en un centro privado de neuro-optometría.MétodosSe realizó un análisis retrospectivo, en un centro privado de neuro-optometría, con revisión de las historias de pacientes consecutivos con diagnóstico m...
Source: Journal of Optometry - July 5, 2018 Category: Opthalmology Source Type: research
Publication bias and the chase for statistical significance
Publication date: April–June 2018Source: Journal of Optometry, Volume 11, Issue 2Author(s): Iván Marín-Franch (Source: Journal of Optometry)
Source: Journal of Optometry - July 5, 2018 Category: Opthalmology Source Type: research
