Institut für Optometrie

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

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  • 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
  • Publikation
    Does air gas aesthesiometry generate a true mechanical stimulus for corneal sensitivity measurement?
    (Wiley, 01.03.2018) Nosch, Daniela; Pult, Heiko; Albon, Julie; Purslow, Christine; Murphy, Paul J
    Aim of this study - to determine: (A) the stimulus temperature inducing no or least change in ocular surface temperature (OST), using the Belmonte Ocular Pain Meter (OPM); and (B) to evaluate if OST remains unchanged with different stimulus durations and airflow rates. A total of 14 subjects (mean age 25.14 ± 2.18 years) participated: (A) OST was recorded using an infrared camera (FLIR A310) during the presentation of airflow stimuli, at five temperatures, ambient temperature (AT) +5°C, +10°C, +15°C, +20°C and +30°C, using the OPM; and (B) OST measurements were repeated with two stimulus temperatures (AT +10°C and +15°C) while varying stimulus durations and airflow rates. Results: (A) Stimulus temperatures of AT +10°C and +15°C induced the least changes in OST (-0.20 ± 0.13°C and 0.08 ± 0.05°C). (B) OST changes were statistically significant with both stimulus temperatures and increased with increasing airflow rates (p < 0.001).
    01A - Beitrag in wissenschaftlicher Zeitschrift
  • Publikation
    Relationship between corneal sensation, blinking, and tear film quality
    (Lippincott Williams & Wilkins, 17.05.2016) Nosch, Daniela; Pult, Heiko; Albon, Julie; Purslow, Christine; Murphy, Paul J
    Purpose. To examine the possible role of corneal sensitivity and tear film quality in triggering a blink by investigating the relationship between blink rate, central corneal sensitivity threshold (CST), ocular surface temperature (OST), tear meniscus height (TMH), tear film quality (noninvasive tear break-up time [NIBUT]), and tear film lipid pattern under normal conditions. Methods. Fortytwo volunteers (average age 27.76+/-5.36 years; 11males) with good ocular health( OcularSurfaceDisease Index, <15.0) were recruited for this cross-sectional cohort study. Blink rate, CST (noncontact corneal air gas aesthesiometry, NCCA), minimum and maximum OST in the central and inferior cornea between blinks (thermal infrared camera), TMH, NIBUT, and lipid pattern of the tear film (Keeler Tearscope Plus) were recorded on the right eye only. Results. Median blink ratewas 11blinks/min (interquartilerange [IR], 6.95 to 17.05), CST was 0.35mbars (IR,0.30to0.40), minimum OST in the central cornea was 35.15°C (IR, 34.58 to 35.50), and NIBUT was 34.55 s (IR, 12.45 to 53.80). Moderate but statistically significant correlations were observed between CST and NIBUT (r = 0.535, p < 0.001), CST and blink rate (r = -0.398, p < 0.001), lipid pattern and OST (r = 0.556, p < 0.001), and between CST and OST (r = 0.371, p = 0.008). The correlations between blink rate and NIBUT (r = -0.696, p < 0.001) and between OST and NIBUT (r = 0.639, p G 0.001; Spearman test) achieved higher significance; this was highlighted by the linear regression model where NIBUT and minimum central and inferior OST were identified as significant predictor variables. Conclusions. There is strong evidence for significant interactions between corneal sensitivity, NIBUT, OST, and blink frequency, emphasizing that ocular surface conditions represent a possible important trigger for the initiation of a blink. However, the mechanisms involved in the initiation of a blink are complex, with local ocular sensory input as only one trigger, along with other external influences and internal factors under cortical control.
    01A - Beitrag in wissenschaftlicher Zeitschrift
  • 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
  • Publikation
    Blink animation softare to improve blinking and dry eye symptoms
    (Lippincott Williams & Wilkins, 09/2015) Nosch, Daniela; Foppa, Curdin; Toth, Mike; Joos, Roland E.
    Purpose: To evaluate if the animation “blink blink” increases blink rate and improves dry eye symptoms during prolonged computer use. Methods: Study part A: Blink rate was recorded at baseline and during computer work of normal subjects without symptoms of dry eye. Half of the subjects used “blink blink,” instructed to blink on animation appearance; the other half used a placebo version for 1 week during computer use. Thereafter, blink rate was recorded again with the use of “blink blink.” Study part B: Blink rate was recorded during computer work with dry eye symptoms (modified Ocular Surface Disease Index > 15.0). Subjects used the test and placebo version of “blink blink” each for 1 week (1 week washout; crossover) and were instructed to blink twice on presentation of the animation. Blink rate and dry eye symptoms were assessed after each phase and compared with baseline. Results: Study part A: Ten subjects participated (mean [±SD] age, 38.3 [±16.0] years; 5 women). A greater increase in blink rate was observed in the test group (5.62 blinks/min for the test group and 0.96 blinks/min for the control group). Study part B: Twenty-four subjects participated (mean [±SD] age, 39.3 [±19.1] years; 11 women). Dry eye symptoms improved during both phases (with test and placebo) to a statistically significant degree (each, p < 0.001). This difference was more marked with the test (−5.42 [±2.86] points) compared with the placebo version (−1.79 [±1.38] points). Blink rate increased with the program by 6.75 (±3.80) blinks/min (p < 0.001), compared with 0.50 (±2.83) blinks/min with placebo (p = 0.396). This difference between test and placebo was statistically significant (p < 0.001). Twenty of the 24 subjects could tolerate “blink blink” well during computer use. Conclusions: Blink rate and dry eye symptoms improved with “blink blink.” The double blink prompted by the animation allowed a decrease in number of presentations and improved acceptance of “blink blink.”
    01A - Beitrag in wissenschaftlicher Zeitschrift
  • Publikation
    Dynamic contour tonometry (DCT) over a thin daily disposable hydrogel contact lens
    (Elsevier, 2010) Nosch, Daniela; Herrmann, Didier; Duddek, Armin P.; Stuhrmann, Oliver M.
    Dynamic Contour Tonometry (DCT) has been shown to measure the intraocular pressure (IOP) independent of corneal physical properties such as thickness, curvature and rigidity. The aim of this study was to find out if DCT remains accurate when it is applied on regularly shaped corneas while a thin, daily hydrogel contact lens (CL) is worn. Methods: This was a prospective, randomised study and included 46 patients (46 right eyes): 26 females and 20 males. The age varied from 22 to 66 years (mean: 43.0±12.70 years). IOP and ocular pulse amplitude (OPA) measurements were taken with and without a daily disposable hydrogel CL (−0.50 D), Filcon IV) in situ (using the DCT), with a randomised order of measurements. Results: The average value for the IOP measurements without CL was 16.51±3.20mmHg, and with CL in situ it was 16.10±3.10mmHg. The mean difference was 0.41mmHg and not found to be statistically significant (p = 0.074). The average value for the OPA measurement without CL was 2.20±0.79mmHg. With CL in situ it was 2.08±0.81mmHg. This gave a mean difference of 0.11mmHg and was statistically significant (p = 0.025). The Bland–Altman plot showed a maximum difference in IOP of +2.44 and −2.00mmHg (CI 0.95). Regarding OPA, the maximum difference was +0.81 and −0.60mmHg (CI 0.95). Conclusion: The presence of a thin hydrogel CL did not affect the accuracy of IOP measurements using the DCT. The ocular pulse amplitude was measured on average 5.45% lower with a CL in situ.
    01A - Beitrag in wissenschaftlicher Zeitschrift