Ocular effects of exposure to low-humidity environment with contact lens wear: A pilot study.

PURPOSE: To compare the ocular effects of exposure to a low-humidity environment with and without contact lens (CL) wear using various non-invasive tests. METHODS: Fourteen habitual soft CL wearers were exposed to controlled low humidity (5% relative humidity [RH]) in an environmental chamber for 90 min on two separate occasions. First, when wearing their habitual spectacles and then, on a separate visit, when wearing silicone hydrogel CLs that were fitted specifically for this purpose. All participants had adapted to the new CL prior to data collection. Three non-invasive objective measurements were taken at each visit: blinking rate, objective ocular scatter (measured using the objective scatter index) and ocular surface cooling rate (measured using a long-wave infrared thermal camera). At each visit, measurements were taken before the exposure in comfortable environmental conditions (RH: 45%), and after exposure to environmental stress (low humidity, RH: 5%). RESULTS: CL wearers showed increased blinking rate (p < 0.005) and ocular scatter (p = 0.03) but similar cooling rate of the ocular surface (p = 0.08) when compared with spectacle wear in comfortable environmental conditions. The exposure to low humidity increased the blinking rate significantly with both types of corrections (p = 0.01). Interestingly, ocular scatter (p = 0.96) and cooling rate (p = 0.73) were not significantly different before and after exposure to low humidity. There were no significant two-way interactions between correction and exposure in any of the measurements. CONCLUSIONS: CLs significantly increased the blinking rate, which prevented a quick degradation of the tear film integrity as it was refreshed more regularly. It is hypothesised that the increased blinking rate in CL wearers aids in maintaining ocular scatter quality and cooling rate when exposed to a low-humidity environment. These results highlight the importance of blinking in maintaining tear film stability.

Visual and Physiological Optics: introduction to the joint feature issue in Biomedical Optics Express and Journal of the Optical Society of America A.

This feature issue collects articles presented at the tenth Visual and Physiological Optics meeting (VPO2022), held August 29-31, 2022, in Cambridge, UK. This joint feature issue between Biomedical Optics Express and Journal of the Optical Society of America A includes articles that cover the broad range of topics addressed at the meeting and examples of the current state of research in the field.

Introduction to Visual and Physiological Optics feature issue of Biomedical Optics Express and JOSA A.

This feature issue collects articles presented at the tenth Visual and Physiological Optics meeting (VPO2022), held August 29-31, 2022, in Cambridge, UK. This joint feature issue between Biomedical Optics Express and Journal of the Optical Society of America A includes articles that cover the broad range of topics addressed at the meeting and examples of the current state of research in the field.

Individualized modeling for the peripheral optics of the human myopic eye.

Individualized optical modelling of the eye is a useful tool to estimate optical properties of the eye from a set of geometrical parameters. In the context of myopia research, it is important to understand not only the on-axis (foveal) optical quality, but also the peripheral profile. This work describes a method to extend on-axis individualized eye modeling to the peripheral retina. Using measurements of corneal geometry, axial distances, and central optical quality from a group of young adults, a crystalline lens model was built to help reproduce the peripheral optical quality of the eye. Subsequent individualized eye models were generated from each of the 25 participants. These models were used to predict the individual peripheral optical quality over the central 40 degrees. Outcomes of the final model were then compared to the actual measurements of peripheral optical quality in these participants, measured with a scanning aberrometer. A high agreement was found between the final model and measured optical quality for the relative spherical equivalent and J0 astigmatism.

Functional visual tests to evaluate the effect of small astigmatism correction with toric contact lenses.

The prescription of daily contact lenses does not often include a full astigmatic correction. We question here whether this full astigmatic correction (for low to moderate astigmatism) provides a substantial improvement in the overall visual performance compared to a more conservative approach based only on the prescription of spherical contact lenses. The visual performance of 56 contact lens neophytes divided in two contact lens fitting groups (toric versus spherical lens fit) was assessed using standard visual acuity and contrast sensitivity tests. A new set of functional tests simulating everyday tasks was also used. Results showed that subjects with toric lenses had significantly better visual acuity and contrast sensitivity than those with spherical lenses. Functional tests did not render significant differences between groups, which was explained by several factors like i) the visual demand of the functional tests, ii) the dynamic blur due to misalignments and iii) small misfits between the available and measured axis of the astigmatic contact lens.

Inverted meniscus intraocular lens as a better optical surrogate of the crystalline lens.

Current intraocular lenses (IOLs) are designed to substitute the cataractous crystalline lens, optimizing focus at the fovea. However, the common biconvex design overlooks off-axis performance, leading to a reduced optical quality in the periphery of the retina in pseudophakic patients compared to the normal phakic eye. In this work, we designed an IOL to provide better peripheral optical quality, closer in that respect to the natural lens, using ray-tracing simulations in eye models. The resulting design was a concave-convex inverted meniscus IOL with aspheric surfaces. The curvature radius of the posterior surface was smaller than that of the anterior surface by a factor that depended on the IOL power. The lenses were manufactured and evaluated in a custom-built artificial eye. Images of a point source and of extended targets were directly recorded at various field angles with both standard and the new IOLs. This type of IOL produces superior image quality in the whole visual field, being a better surrogate for the crystalline lens than the commonly used thin biconvex intraocular lenses.

Intraocular Scattering, Blinking Rate, and Tear Film Osmolarity After Exposure to Environmental Stress.

Purpose: Dry environments, such as those in offices or aircraft cabins, can potentially generate ocular discomfort and alter the tear film. We compare light scatter, blinking rate, and tear osmolarity in young and older subjects after exposure to low humidity using a controlled environmental chamber. Methods: Two groups of healthy subjects were recruited; younger (N = 13, 27 ± 6 years) and older (N = 23, 71 ± 7 years). Measurements were carried out before and after 90-minute exposure to low relative humidity (5%) and constant temperature (23 degrees). Ocular light scatter was measured using a double-pass instrument (OQAS, Visiometrics, Spain). Blinking rate was monitored using an infrared video camera. Tear osmolarity was measured using the TearLab system (Escondido, CA, USA). Results: Ocular light scatter increased by a factor of 10% after exposure to low humidity in the older group (P = 0.03) but did not change significantly in the younger group. Blinking rate increased significantly (40% more blinks) in both groups but there was no difference between the groups. No significant differences in osmolarity were shown between two age groups or as result of environmental stress. Conclusions: Exposure to dry environment increased light scatter in older subjects. Although more blinks were triggered in both younger and older groups to prevent corneal dehydration, there was no difference between the groups. Blink rate and osmolarity are not associated with the difference in light scatter. Translational Relevance: Our work approaches a clinical care problem using basic research methods (measuring ocular scatter and blink ratio).

A Comparison Between Refraction From an Adaptive Optics Visual Simulator and Clinical Refractions.

Purpose: The Visual Adaptive Optics (VAO) is an adaptive optics visual simulator with an embedded Hartmann-Shack aberrometer that can give objective and subjective refraction measures. The aim of the present study was to compare the findings of the objective and subjective refractions from the VAO with a commercial autorefractometer (Topcon Corp., Tokyo, Japan) and a subjective refraction by an optometrist. The influence of age, refractive error type, and presence of ocular diseases was ascertained. Methods: The refractive error was obtained in 469 participants using the four techniques mentioned. Data were analyzed with power vectors mean spherical equivalent, the vertical Jackson-Cross-Cylinder, and the oblique Jackson-Cross-Cylinder. Age, refractive error type (myopia, emmetropia, hyperopia) and presence of ocular diseases (yes, no) were included as covariates. Agreement was assessed using the 95% interval of agreement. Results: The median spherical equivalent difference and the interval of agreement for all the participants with the VAO subjective, VAO objective, and autorefraction with the clinical subjective refraction were (+0.13, 1.80 diopters [D]), (+0.38, 1.80 D), and (-0.38, 2.10 D), respectively. When considering only healthy participants, the results were (+0.06, 1.70 D), (+0.38, 1.60 D) and (-0.25, 1.80 D), respectively. When considering only those participants with any ocular condition, the results with VAO subjective, VAO objective and autorefraction were (+0.13, 2.50 D), (+0.31, 2.70 D), and (-0.50, 4.80 D), respectively. Conclusions: The VAO subjective refraction is more accurate than VAO objective refraction and autorefraction, regardless of refractive error, age, or the presence of ocular conditions. The presence of ocular conditions significantly deteriorates the accuracy of all refraction methods. Translational Relevance: Reported clinical comparisons between different types of standard refraction methods and a new adaptive optics refraction instrument (VAO) are in good agreement and support the further development of this method to increase refraction accuracy and to refract quicker than standard procedures.

Author Correction: Comparison of different smartphone cameras to evaluate conjunctival hyperaemia in normal subjects.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

A low-cost 2-D video system can accurately and reliably assess adaptive gait kinematics in healthy and low vision subjects.

3-D gait analysis is the gold standard but many healthcare clinics and research institutes would benefit from a system that is inexpensive and simple but just as accurate. The present study examines whether a low-cost 2-D motion capture system can accurately and reliably assess adaptive gait kinematics in subjects with central vision loss, older controls, and younger controls. Subjects were requested to walk up and step over a 10 cm high obstacle that was positioned in the middle of a 4.5 m walkway. Four trials were simultaneously recorded with the Vicon motion capture system (3-D system) and a video camera that was positioned perpendicular to the obstacle (2-D system). The kinematic parameters (crossing height, crossing velocity, foot placement, single support time) were calculated offline. Strong Pearson's correlations were found between the two systems for all parameters (average r = 0.944, all p < 0.001). Bland-Altman analysis showed that the agreement between the two systems was good in all three groups after correcting for systematic biases related to the 2-D marker positions. The test-retest reliability for both systems was high (average ICC = 0.959). These results show that a low-cost 2-D video system can reliably and accurately assess adaptive gait kinematics in healthy and low vision subjects.

Characterization of the ocular surface temperature dynamics in glaucoma subjects using long-wave infrared thermal imaging: publisher's note.

This publisher's note corrects the funding section in J. Opt. Soc. Am. A36, 1015 (2019)JOAOD61084-752910.1364/JOSAA.36.001015.

Characterization of the ocular surface temperature dynamics in glaucoma subjects using long-wave infrared thermal imaging.

We evaluated the dynamics of ocular surface temperature using thermal imaging in 21 glaucoma subjects and 19 healthy subjects. On opening of the eye, subjects with glaucoma showed significantly cooler temperatures in the central cornea compared to the control group. The upper eyelid was also significantly cooler just before the eye opened. Immediately after opening the eye, the dynamic of temperature change was different in the two groups. In subjects with glaucoma, the eyes cooled significantly faster, with an average decrease of 0.49°C during the first second compared to 0.24°C in the control group. Our results support the hypothesis that both the stability of the tear film and changes in the ocular blood supply in subjects with glaucoma play an important role in thermal dynamics of the ocular surface.

Visual and physiological optics: introduction to the Journal of the Optical Society of America A feature issue.

The 9th European Meeting on Visual Physiological Optics (VPO2018) was held August 29-31, 2018, in Athens, Greece. This issue of the Journal of the Optical Society of America A (JOSA A) is a dedicated feature, including numerous articles that span a large range of visual optics related topics, ranging from geometrical optics to visual psychophysics and from optical metrology to ophthalmic diagnostic technologies. The next VPO meeting will be held August 2020 in Cambridge, UK.

Comparison of different smartphone cameras to evaluate conjunctival hyperaemia in normal subjects.

Despite the significant advantages that smartphones' cameras can provide in teleophthalmology and artificial intelligence applications, their use as black-box systems for clinical data acquisition, without adequate information of the quality of photographs can compromise data accuracy. The aim of this study is to compare the objective and subjective quantification of conjunctival redness in images obtained with calibrated and non-calibrated cameras, in different lighting conditions and optical magnifications. One hundred ninety-two pictures of the eye were taken in 4 subjects using 3 smartphone cameras{Bq, Iphone, Nexus}, 2 lighting levels{high 815 lx, low 122 lx} and 2 magnification levels{high 10x, low 6x}. Images were duplicated: one set was white balanced and color corrected (calibrated) and the other was left as it was. Each image was subjective and objectively evaluated. There were no significant differences in subjective evaluation in any of the conditions whereas many statistically significant main effects and interaction effects were shown for all the objective metrics. The clinician's evaluation was not affected by different cameras, lighting conditions or optical magnifications, demonstrating the effectiveness of the human eye's color constancy properties. However, calibration of a smartphone's camera is essential when extracting objective data from images.

Manejo del estrés moderado con una asociación de plantas medicinales adaptógenas, vitamina B6 y magnesio / Controle do stress moderado com uma asso-ciação de plantas medicinais adaptogénicas, vitamina B6 e magnésio / Moderate stress management strategy with an association of adaptogenic medicinal plants, vitamin B6 and magnesium

El objetivo de este trabajo fue evaluar la eficacia y seguridad de un producto comercial compuesto por extractos secos de raíz de rodiola y raíz de eleuterococo, con magnesio y vitamina B6, en el manejo de síntomas psíquicos y somáticos asociados al estrés. Se realizó un es-tudio observacional, prospectivo, multicéntrico, abierto, en el ámbito de atención primaria en el que participaron 112 pacientes, con una puntuación inicial de 14-30 puntos en la escala de Hamilton para la ansiedad (HAMA). Fueron tratados durante 50 días con 2 o 3 comprimidos diarios del producto, observándose una disminución promedio de 8,5 puntos en la escala HAMA. Un 53,4% de los pacientes acabó el estudio con una puntuación menor de 14 puntos en la escala HAMA, lo que equivale a "ausencia ansiedad". Asimismo, se estudiaron los efectos del producto mediante la escala CGI-gravedad, consiguiendo una disminución de 1,52 puntos, y una tolerabilidad excelente. Se concluye que el producto estudiado permite una mejoría altamente significativa (p < 0,001) y una remisión de los síntomas asociados al estrés leve y moderado y que puede considerarse una opción terapéu-tica adecuada en pacientes en fases tempranas del estrés

O objetivo deste trabalho foi avaliar a eficácia e segurança de um produto comercial composto de extratos secos de raízes e rizomas de rodiola e de raízes de eleuterococo, com magnésio e vitamina B6, no controlo de sintomas psíquicos e somáticos associados ao stress. Um estudo obser-vacional, prospectivo, multicêntrico e aberto foi conduzido no âmbito dos cuidados primários de saúde, no qual 112 pacientes participaram, com uma pontuação inicial de 14 a 30 pontos na escala de Hamilton para ansiedade (HAMA). Eles foram tratados durante 50 dias com 2 ou 3 comprimidos por dia do produto, observando uma redução média de 8,5 pontos na escala HAMA. 53,4% dos pacientes terminaram o estudo com uma pontuação inferior a 14 pontos na escala HAMA, o que equivale a "ausência de ansiedade". Da mesma forma, os efeitos do produto foram estudados através da escala de severidade CGI, alcançando um decréscimo de 1,52 pontos e uma excelente tolerabilidade. Conclui-se que o produto estudado permite uma melhoria altamente significativa (p <0,001) e uma remissão dos sin-tomas associados ao stress leve e moderado e que pode ser considerada uma opção terapêutica adequada em pa-cientes nos estágios iniciais de stress

The objective of this work was to evaluate the efficacy and safety of a commercial product composed of dry extracts of root and rhizome of rhodiola and eleutherococcus root, with magnesium and vitamin B6, in the management of psychic and somatic symptoms associated with stress. An observational, prospective, multicenter, open study was conducted in the primary care setting in which 112 patients participated, with an initial score of 14-30 points on the Hamilton scale for anxiety (HAMA). They were treated during 50 days with 2 or 3 tablets daily of the product, observing an average decrease of 8.5 points in the HAMA scale. 53.4% of the patients finished the study with a score lower than 14 points on the HAMA scale, which is equivalent to "absence anxiety". Likewise, the effects of the product were studied through the CGI-severity scale, achieving a decrease of 1.52 points, and excellent toler-ability. It is concluded that the product studied allows a highly significant improvement (p <0.001) and a remission of the symptoms associated with mild and moderate stress and that it can be considered an adequate therapeutic option in patients in the early stages of stress

Initial Clinical Results With a Novel Monofocal-Type Intraocular Lens for Extended Macular Vision in Patients With Macular Degeneration.

PURPOSE: To determine the feasibility of a novel intraocular lens (IOL) designed to improve retinal image quality at up to 10° of retinal eccentricity and optionally provide retinal magnification in patients with macular disease. METHODS: In this prospective, interventional pilot study, 8 eyes of 7 patients with bilateral dry age-related macular degeneration and 1+ or less cataract underwent phacoemulsification and capsular bag implantation of a single, injectable, hydrophobic acrylic IOL. Safety and efficacy were assessed by monitoring logMAR corrected distance and near visual acuity, intraocular pressure, specular microscopy, 80-point visual field testing, and anterior segment and macular optical coherence tomography at baseline and 1 week, 1 month, and 2 months postoperatively. Microperimetry was undertaken at baseline and 1 and/or 2 months postoperatively. Reading performance was assessed at baseline and 1 month postoperatively using the Minnesota low vision reading chart (MNREAD; Precision Vision, LaSalle, IL). RESULTS: Safety outcomes were equivalent to standard monofocal IOLs. Visual acuities improved in all patients. Mean corrected distance visual acuity improved from 0.93 ± 0.22 preoperatively to 0.59 ± 0.25 at 2 months postoperatively. Mean reading speed increased from 28 ± 19 to 44 ± 31 words per minute. Mean microperimetry threshold sensitivities increased from 8.2 ± 4.6 to 12 ± 5.6 dB. Mean percentage of fixation points within a 4° circle increased from 77% ± 17% to 91% ± 11% with evidence for progressive movement of preferred retinal loci away from areas of geographic atrophy. CONCLUSIONS: Initial results indicate this novel IOL has a safety profile comparable with standard IOLs. Visual benefits may exceed those obtained with existing technologies in patients with macular disease. Further work is required to determine the full potential of extended macular vision technology. [J Refract Surg. 2018;34(11):718-725.].

Variability in angle κ and its influence on higher-order aberrations in pseudophakic eyes.

PURPOSE: To observe the variability in angle κ in pseudophakic patients and assess its correlation with optical biometry measurements and higher-order aberrations (HOAs). SETTING: Hanusch Hospital, Vienna, Austria. DESIGN: Prospective case series. METHODS: This study included patients who had cataract surgery 3 months to 1 year before study recruitment. In all cases, Purkinje meter images were taken. In addition, partial coherence interferometry measurement (IOLMaster) of the axial intraocular lens (IOL) position was performed. In a subgroup of patients, an additional Hartmann-Shack sensor measurement was taken to assess HOAs (WASCA). RESULTS: This study comprised 395 eyes of 349 patients. The mean age of the 210 women and 139 men was 74.1 years ± 8.6 (SD) (range 44 to 91 years). The mean tilt (pupillary axis) and decentration were 3.9 ± 2.3 degrees (range 0.2 to 16.2 degrees) and 0.4 ± 0.2 mm (range 0.0 to 1.7 mm), respectively. The mean angle κ was 5.2 ± 2.6 degrees (range 0.3 to 13.9 degrees), and the mean orientation of this modulus was 189.5 ± 53.2 degrees (range 25.3 to 339.7 degrees). CONCLUSION: The variability in the angle κ was high.

Intraocular lenses in age-related macular degeneration.

PURPOSE: The aim of this work is to review the lenses, assessing their advantages and disadvantages. We describe a total of seven types of intraocular lenses (IOLs) recommended for age-related macular degeneration (AMD). METHODS: We used the PubMed web platform to search for implantable devices in various stages of AMD. We searched for both prospective and retrospective studies and also case reports. RESULTS: Clinical results in AMD patients have been described for a total of seven types of IOLs recommended for AMD: an implantable miniature telescope (IMT), IOL-VIP System, Lipshitz macular implant (LMI), sulcus-implanted Lipshitz macular implant, LMI-SI, Fresnel Prism Intraocular Lens, iolAMD and Scharioth Macula Lens. CONCLUSIONS: We conclude that to objectively ascertain the effectiveness and safety of these lenses, further independent clinical studies with longer follow-up data are necessary prior to the general use of these optical devices.

Comparison of intraocular lens decentration and tilt measurements using 2 Purkinje meter systems.

PURPOSE: To evaluate the difference in intraocular lens tilt and decentration measurements with 2 Purkinje meters. SETTING: Vienna Institute for Research in Ocular Surgery, Hanusch Hospital, Vienna, Austria. DESIGN: Prospective evaluation of diagnostic test. METHODS: This single-center study included pseudophakic patients in 2 substudies in which 3 consecutive measurements were performed with 2 Purkinje meters (Spanish and German). In substudy 1, an inexperienced examiner performed all measurements after a short learning period. In substudy 2, all measurements were taken by experienced examiners under direct supervision of the inventors of the devices. RESULTS: Substudy 1 included 53 pseudophakic eyes in which all 53 scans were successful with the Spanish device; however, only 35 measurements (66%) were successful with the German Purkinje meter. The mean tilt measured with the Spanish Purkinje meter was 4.35 degrees ± 2.50 (SD) and 9.20 ± 6.96 degrees with the German Purkinje meter. The mean decentration was 0.44 ± 0.19 mm and 0.74 ± 0.91 mm, (P = .44), respectively. In substudy 2 (29 pseudophakic eyes), the number of successful scans was 29 (100%) and 18 (62%) for the Spanish meter and German Purkinje meter, respectively. The mean horizontal and vertical tilt difference vector between the 2 systems was 4.89 ± 3.24 degrees and 7.57 ± 3.82 degrees, respectively. CONCLUSIONS: Concerning clinical feasibility, the Spanish Purkinje meter had a greater percentage of successful scans than the German device. In addition, this device measured significantly higher tilt values than the Spanish Purkinje meter.

Micrometric Control of the Optics of the Human Eye: Environment or Genes?

Purpose: The human eye has typically more optical aberrations than conventional artificial optical systems. While the lower order modes (defocus and astigmatism) are well studied, our purpose is to explore the influence of genes versus the environment on the higher order aberrations of the optical components of the eye. Methods: We have performed a classical twin study in a sample from the Region of Murcia (Spain). Optical aberrations using a Hartmann-Shack sensor (AOnEye Voptica SL, Murcia, Spain) and corneal aberrations (using corneal topography data) were measured in 138 eyes corresponding to 69 twins; 36 monozygotic (MZ) and 33 dizygotic (DZ) pairs (age 55 years, SD 7 years). Intraclass correlation coefficients (ICCs) were used to estimate how strongly aberrations of twins resemble each other, and genetic models were fitted to quantify heritability in the selected phenotypes. Results: Genes had a significant influence in the variance of most of the higher order aberration terms (heritability from 40% to 70%). This genetic influence was observed similarly in both cornea and complete eye aberrations. Additionally, the compensation factor of spherical aberration in the eye (i.e., how much corneal spherical aberration was compensated by internal spherical aberration) was found under genetic influence (heritability of 68%). Conclusions: There is a significant genetic contribution to the variance of aberrations of the eye, not only at macroscopic levels, as in myopia or astigmatism, but also at microscopic levels, where a few micrometers changes in surface topography can produce a large difference in the value of the optical aberrations.