Institut für Optometrie

Dauerhafte URI für die Sammlunghttps://irf.fhnw.ch/handle/11654/47

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  • Vorschaubild
    Publikation
    Binocular advantages in reading revisited. Attenuating effects of individual horizontal heterophoria
    (Bern Open Publishing, 09.12.2019) Jainta, Stephanie; Joss, Joëlle
    Reading with two eyes necessitates efficient processes of binocular vision, which provide a single percept of the text. These processes come with a binocular advantage: binocular reading shows shorter average fixation durations and sentence reading times when compared to monocular reading. A couple of years ago, we showed for a small sample (N=13) that binocular advantages critically relate to the individual heterophoria (the resting state of vergence). In the present, large-scale replication we collected binocular eye movements (Eyelink II) for 94 participants who read 20 sentences monocularly and 20 sentences binocularly. Further, individual heterophorias were determined using three different optometric standards: objective eye tracking (EyeLink II at 60 cm), Maddox wing test (at 30 cm) and measures following the “Guidelines for the application of the Measuring and Correcting Methodology after H.-J. Haase” (MCH; at 6 m). Binocular eye movements showed typical pattern and we replicated (1) binocular advantages of about 25 ms for average fixation durations and (2) a reduction in binocular advantages when heterophoria increased – but only when heterophoria was identified by EyeLink II or Maddox wing measures; MCH measures of heterophoria did not affect binocular advantages in reading. For large heterophorias binocular reading even turned into a disadvantage. Implications for effect estimations and optometric testing will be discussed.
    01A - Beitrag in wissenschaftlicher Zeitschrift
  • Vorschaubild
    Publikation
    Hornhautsensibilität Teil 1: Grundlagen und Messung
    (2013) Nosch, Daniela
    Die Hornhautsensibilität wird durch eine neurologische Reaktion der frei liegenden Nervenfaserenden im Hornhautepithel bestimmt. Diese registrieren mechanische, chemische und thermische Reizungen und versorgen somit die Hornhaut mit einem wichtigen Schutzmechanismus vor schädlichen Einflüssen aus der Umwelt: Eine mechanische Reizung bewirkt eine Empfindung von Schmerz, eine elektrische Reizung verursacht Schmerzen und Irritation, ein kalter Stimulus wird als kühlend wahrgenommen, ein warmer Stimulus hingegen verursacht Irritation, während eine chemische Reizung als brennend oder gar stechender Schmerz empfunden wird. In diesem Artikel werden die Wissensgrundlagen zu den oberflächlichen Hornhautnerven zusammengefasst: deren Rolle bei der Erhaltung eines gesunden Stoffwechsels der Hornhaut, ihre Innervation, die verschiedenen schmerzempfindlichen cornealen Nerventypen und ihre Nervenenden, die Morphologie des epithelialen subbasalen Nervenplexus und schließlich die Messung der Hornhautsensibilität.
    01B - Beitrag in Magazin oder Zeitung
  • Vorschaubild
    Publikation
    Periphere Epitheliale Corneale Hypertrophie (PECH) beim Tragen weicher hydrophiler Kontaktlinsen
    (05/2016) Bronner, Rainer; Nosch, Daniela
    Peripheral epithelial corneal hyperfluorescence (PECH) in daily soft contact lens (CL) wear is described by three case reports. In vivo confocal microscopy (IVCM) measurements show the presence of epithelial corneal hypertrophy on affected eyes. A statistical analysis of a group of patients with PECH in comparison to a control group suggests a hypoxic cause for PECH. Further clinical studies with balanced patient populations are required to confirm these findings, as the population of this study group was affected by a selection bias.
    01B - Beitrag in Magazin oder Zeitung
  • Vorschaubild
    Publikation
    Hornhautsensibilität Teil 2: Der Einfluss von Kontaktlinsen
    (01/2014) Nosch, Daniela
    Die Messung der Hornhautsensibilität ermöglicht eine Beurteilung der Funktionstüchtigkeit der schmerzempfindlichen oberflächlichen Hornhautnerven. Daraus ergeben sich wichtige Hinweise auf die Gesundheit der Hornhaut im Verlauf eines Erkrankungsprozesses, während der Heilungsphase nach einer Verletzung oder einem refraktiv-chirurgischen Eingriff, sowie beim Kontaktlinsentragen. Die Nervenenden in der Hornhaut und Bindehaut sind über ein komplexes Feedback-Netzwerk (unter Aktivierung von Hirnstamm Regelkreisen) mit den Tränendrüsen und dem Musculus orbicularis oculi verbunden, um die Gesundheit der Augenvorderfläche und den Tränenfilm jederzeit zu überwachen und zu erhalten. Für die Regulierung des Heilungsprozesses nach Verletzungen lösen sie die Freigabe von trophischen Substanzen (Neuropeptide und Neurotrophine) aus. Dieser Beitrag fasst die publizierte Literatur über den Einfluss des Kontaktlinsentragens zusammen und erläutert, welche Auswirkungen verschiedene Kontaktlinsenmaterialien und Tragemodi haben.
    01B - Beitrag in Magazin oder Zeitung
  • Vorschaubild
    Publikation
    Hornhautsensibilität Teil 3: Das Trockene Auge, Keratokonus, refraktive Chirurgie, Keratoplastik und systemische Erkrankungen
    (02/2014) Nosch, Daniela
    Die vorangegangenen beiden Artikel machten deutlich, welche wichtige Rolle die oberflächlichen Nerven im cornealen epithelialen sub-basalen Nervenplexus für eine gesunde Hornhaut spielen und wie sie in ihrer Reaktionsfähigkeit durch das Tragen von Kontaktlinsen beeinflusst werden können. Dieser dritte Artikel handelt von möglichen Änderungen der Hornhautsensibilität bei der Entwicklung des trockenen Auges (und in seinem weiteren Krankheitsverlauf), bei Keratokonus, refraktiver Chirurgie, Keratoplastik sowie infolge systemischer Erkrankungen, wie beispielsweise der peripheren Neuropathie bei Diabetes.
    01B - Beitrag in Magazin oder Zeitung
  • Vorschaubild
    Publikation
    The accuracy of dynamic contour tonometry over soft contact lenses
    (Lippincott Williams & Wilkins, 02/2013) Gogniat, Fabrice; Steinegger, Daniela; Nosch, Daniela; Joos, Roland E; Goldschmidt, Michael
    Purpose. Dynamic contour tonometry (DCT) has been shown to measure the intraocular pressure (IOP) independently of corneal thickness. This study aimed to investigate if DCT remains accurate when the IOP measurement is taken over soft contact lenses (CLs) of different thicknesses and material characteristics. Methods. This was a prospective clinical study that included 42 patients. Subject age was 22 to 59 years (26.5 T 6.3 years). Intraocular pressure and ocular pulse amplitude (OPA) measurements were taken under topical anesthesia without CLs and over various daily disposable CLs with j0.50, +5.00, and j5.00 diopters (D) in hydrogel (Nelfilcon A) and in silicone hydrogel (Narafilcon A) materials. Results. No statistically significant differences were found when comparing the IOP measurements obtained using either of the different CL powers of j0.50 or j5.00 D, irrespective of which CL material was being used. However, the difference of 0.62mmHg observed when the Nelfilcon Awith a power of +5.00Dwas used turned out to be highly statistically significant (p = 0.0002), whereas the Narafilcon Awith the same power of +5.00 D, with a small difference of j0.16 mm Hg, was not. Regarding OPA measurements, no significant differences were found between measurements with and without CL neither for different materials nor for change in dioptrical power (F = 0, p = 1.000). Conclusions. This study showed good reliability of IOP and OPA measurements over CLs with varying thickness profiles and different soft materials when using the DCT. Only a small but statistically significant difference of 0.62mmHg was found for the IOP measurement with the hydrogel CL of +5.00 D compared with ‘‘no CL.’’
    01A - Beitrag in wissenschaftlicher Zeitschrift
  • Vorschaubild
    Publikation
    Effects of Prism Eyeglasses on Objective and Subjective Fixation Disparity
    (Public Library of Science, 02.10.2015) Schroth, Volkhard; Joos, Roland; Jaschinski, Wolfgang
    In optometry of binocular vision, the question may arise whether prisms should be included in eyeglasses to compensate an oculomotor and/or sensory imbalance between the two eyes. The corresponding measures of objective and subjective fixation disparity may be reduced by the prisms, or the adaptability of the binocular vergence system may diminish effects of the prisms over time. This study investigates effects of wearing prisms constantly for about 5 weeks in daily life. Two groups of 12 participants received eyeglasses with prisms having either a base-in direction or a base-out direction with an amount up to 8 prism diopters. Prisms were prescribed based on clinical fixation disparity test plates at 6 m. Two dependent variables were used: (1) subjective fixation disparity was indicated by a perceived offset of dichoptic nonius lines that were superimposed on the fusion stimuli and (2) objective fixation disparity was measured with a video based eye tracker relative to monocular calibration. Stimuli were presented at 6 m and included either central or more peripheral fusion stimuli. Repeated measurements were made without the prisms and with the prisms after about 5 weeks of wearing these prisms. Objective and subjective fixation disparity were correlated, but the type of fusion stimulus and the direction of the required prism may play a role. The prisms did not reduce the fixation disparity to zero, but induced significant changes in fixation disparity with large effect sizes. Participants receiving base-out prisms showed hypothesized effects, which were concurrent in both types of fixation disparity. In participants receiving base-in prisms, the individual effects of subjective and objective effects were negatively correlated: the larger the subjective (sensory) effect, the smaller the objective (motor) effect. This response pattern was related to the vergence adaptability, i.e. the individual fusional vergence reserves.
    01A - Beitrag in wissenschaftlicher Zeitschrift