Tag Archives: Tübingen

1st Annual Meeting

The following article is presented to you by Pablo Sanz and Miguel García
For all the general public, some statements may require deeper knowledge of science.

During the last week of November, on the shores of the Neckar River (Tübingen, Germany) and just a few minutes walking from the place where Kepler observed its first eclipse though a projection of one hole at the vaults of Tübingen Cathedral, our First Annual Meeting was held consisting of all the early stage researcher (ESR), supervisors and members of the MyFUN program.

Throughout this meeting, the project teams met together, stroked up a friendly conversations and suggestions about how each project can starts out with the best possible resources and support available.

The main purpose of each of these projects remain to try and achieve better knowledge and answers regarding the myopia development, considering three specific research Work Packages (WP):

  • WP1: Unknown features of the visual feedback-control loop for eye growth. (Projects: 1, 2, 3, 4, 5, 6).
  • WP2: Biological features of the visually-guided signalling cascades controlling eye growth. (Projects: 7, 8, 9, 10).
  • WP3: Visual performance, adaptation and training. (Projects: 11, 12, 13, 14).

During all the Early Stage Researchers presentations we could get some of the specific objectives, and the key activities regarding all the projects. All this information is listed below:

  1. Accommodation and undercorrection.

ESR Name: Dmitry Romashchenko. Supervisors: Linda Lundström; Peter Unsbo.

Purpose: To study the interactions between the position of the image shell, determined by the accommodation, and the retinal image quality, which is used by the retina to adjust the rates of eye growth. The data will be analyzed for single cases in high details rather than statistical measurements for average values.
The main target is to know in detail what happens with accommodation during undercorrection and with no correction of myopia and how this affects the defocus error signal in the peripheral retina.

  1. Why suddenly myopia?

ESR Name: Andrea Carrillo Aleman. Supervisors: Frank Schaeffel; Marita Feldkaemper; Sandra Bernhard.

Purpose: to analyse accommodation behaviour, using infrared photorefraction, and clarify whether the development of myopia may start because accommodation gives up to compensate for the lenses, generating an error signal on the retina.

  1. More progression with new spectacles?

ESR Name: Miguel Garcia Garcia. Supervisors: Siegfried Wahl; Arne Ohlendorf.

Up to date the single vision spectacles wear are the most used way to correct myopia, besides the different availability of treatments to slow its progression. For that reason, a deeper knowledge of how them act over the eye structures is required.

Purpose: to test the ocular structures in young subjects, just becoming myopic, in close detail by daily or at least weekly measurements with low coherence interferometry, OCT, and photorefraction, before and after new corrective lenses are prescribed.

  1. Crystalline lens and myopia.

ESR Name: Geethika Muralidharan. Supervisors: Susana Marcos; Carlos Dorronsoro; Sergio Barbero; Daniel Pascual; Enrique Bustos.

Purpose: to investigate statistical differences in lens thickness, and lens geometry between myopes and emmetropes, as well as their potential relationships with the magnitude of refractive error, ACD, ACV and AL and investigate the astigmatic axis of the lens surfaces in relation to the corneal astigmatic axis, and the degree of compensation of corneal and internal astigmatism in myopes and emmetropes.

  1. Sign of defocus and eye growth.

ESR Name: Najnin Sharmin. Supervisors: Brian Vohnsen.

Purpose: to study monocular and binocular accommodation with fast wavefront sensing and adaptive optics (>100 Hz) by setting up a stimulation system that will automatically eliminate size, contrast, and brightness clues by use of tuneable liquid filters. It will be tested on myopes if there are marked differences in response between the two groups.

  1. Near work and myopia.

ESR Name: Manto Chouliara. Supervisors: P. Artal; P. Prieto; J. Tabernero; J. Fernandez.

Purpose: to study the image defocus on the retina with yet unachieved precision and resolution in both myopic and emmetropic subjects, and in both eyes at the same time. The question of whether there is a significant “lag of accommodation” during binocular reading will be answered.

  1. In vivo markers of myopia development: changes in fundal reflectance.

ESR Name: Barbara Swiatczak. Supervisors: Frank Schaeffel; Marita Feldkaemper.

Purpose: To find out whether changes in fundal reflectance relate to metabolic state and biochemical signals associated with changes in eye growth, we will sample fundal reflectance in chickens in high detail while their eyes are covered with diffusers, negative lenses and positive lenses for variable periods of time. Using a custom developed procedure to measure the spectral fundal reflectance in alert chickens (derived from white light photorefraction), we will determine the time courses and magnitude of changes in fundal reflectance for different light exposures in chickens.

  1. Inter-individual variability of myopia.

ESR Name: Sandra Gisbert Martinez. Supervisors: Frank Schaeffel; Marita Feldkaemper; Sandra Bernhard.

Purpose: to track the development of deprivation myopia in individual chickens by at least one measurement of ocular biometry and refractive state per day. The slope of refractive change over time will be determined (the gain). Individual gains will be correlated with the patterns and frequency ratios of the different cone types as determined by the analysing the oil droplets in retinal flatmounts.

  1. Inheritance of the peripheral optics of the eye.

ESR Name: Dibyendu Pusti. Supervisors: P. Artal; P. Prieto; J. Tabernero; J. Fernandez.

Purpose: to be able to find out in how far the pattern of peripheral aberrations and refractive errors is inherited. These data have important implication for the understanding of the roles of peripheral defocus on the development of myopia. They also have implications for the prediction of the risk of myopia in humans.

  1. Stiles-Crawford Effect and Myopia.

ESR Name: Alessandra Carmichael Martins. Supervisors: Brian Vohnsen.

Purpose: A  system  that  allows  measurements  of  the  psychophysical  and  the  optical Stiles‑Crawford  effects for the foveal  and parafoveal regions, respectively, will be built. Both techniques will be applied on healthy subjects and on subjects with different degrees of myopia. Previous studies have indicated a slight reduction in directionality for highly myopic eyes with psychophysical techniques but this remains to be confirmed with objective measurements. With this project, such decrease will quantify and clarify its relationship to accommodation as well as to emmetropisation.

  1. Myopia, cycloplegia, and training of accommodation.

ESR Name: Pablo Sanz Diez. Supervisors: Siegfried Wahl; Arne Ohlendorf.

Purpose: to study the plasticity of accommodation in myopes and to investigate if accommodation can be trained or shifted and whether the level of tonic accommodation is paradoxically higher, and why. During this project a continuously recording photorefractor sampling at 100 Hz that emits a sound with the frequency coupled to accommodation tonus will be used. Emmetropic and myopic subjects will be trained to achieve their most relaxed accommodation state and differences in their adaptable amplitudes will be determined.

  1. Visual performance with bifocal correction to inhibit myopia.

ESR Name: Neeraj K. Singh. Supervisors: Prof. Susana Marcos

Purpose: An Adaptive Optics and Simultaneous Vision Simulator (SimVis) developed in the host laboratory will be used to mimic experimentally bifocal corrections of different patterns (concentric vs angularly segmented; centre vs peripheral near add; different addition magnitudes) and measure visual performance of young observers with bifocal corrections: accommodation, visual acuity & visual perception.

The lag of accommodation with bifocal corrections and variation in visual performance across different bifocal corrections (different patterns and near additions) will be determined. The investigators aim to propose the most suitable bifocal correction to interfere with myopia development.

  1. Adaptive optics technology to assess myopia development and correction.

ESR Name: Nikolai Suchkov. Supervisors: B. Jaeken; J. Fernandez; P. Artal

Purpose: To develop a new generation of adaptive optics visual simulator, allowing to measure high ametropes and pathologic patients. The device will allow to measure virtually any eye, and to simulate a solution, correcting both low and high order aberrations. For the increased dioptric range, a tunable lens will be used, allowing to modulate defocus in a range of ± 10D, meanwhile a spatial light modulator will be compensating for the rest of aberrations. The stimulus for subjective measurements will be provided by a digital light processing projector. In order to simulate solutions for different pupil sizes, a motorized exit pupil will be introduced.

  1. Asymmetry in the effects of defocus on vision.

ESR Name: Petros Papadogiannis. Supervisors: Linda Lundström; Peter Unsbo.

The detection of the sign of defocus by the foveal as well as by the peripheral retina is essential for the control of both accommodation and eye growth. The amount of additional blur cannot provide this information since it is symmetrical when the same amount of defocus is imposed in either direction. However, asymmetries in visual performance under positive and negative defocus have been found for both foveal and peripheral vision in myopes, but not in emmetropes .

Purpose: The foveal and peripheral vision will be evaluated with different amounts and signs of defocus for myopic and emmetropic subjects under natural conditions. As the chromatic and higher order aberrations (more irregular optical errors) of the eye can give sign-dependent blur, the same measurements also have to be performed under controlled optical conditions. For this purpose, a peripheral adaptive optics system will be used to remove any asymmetries in the optical blur during the vision evaluation. The system will also be updated for high-resolution foveal measurements.

During the following days, the first Winter School took place, giving the chance to the ESR to enter widely in some threads due lectures from PIs and experts and some workshops at the AugenKlinik (EUKT), Tübingen.

Here we let you some pictures from the lectures, and the social events from afterwards.

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