1 / 16

Jai Mata Di The Mechanism for Defocus-driven Occular Growth

Jai Mata Di The Mechanism for Defocus-driven Occular Growth. The Eye. www.ahaf.org. Lens . Power ( Diopters ) focal length (metres) 1 D 1 m 2 D .5 m Convex lens (has a positive power e.g +1.5 D) focal point forms convergent light

spiro
Télécharger la présentation

Jai Mata Di The Mechanism for Defocus-driven Occular Growth

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Jai Mata Di The Mechanism for Defocus-driven Occular Growth

  2. The Eye www.ahaf.org

  3. Lens • Power (Diopters) focal length (metres) 1 D 1 m 2 D .5 m • Convex lens (has a positive power e.g +1.5 D) focal point forms convergent light • Concave lens (has negative power e.g -2D) focal point is traced back from diverging light

  4. http://www.math.ubc.ca/~cass/courses/m309-01a/chu/MirrorsLenses/lenses.htmhttp://www.math.ubc.ca/~cass/courses/m309-01a/chu/MirrorsLenses/lenses.htm

  5. Lens Accommodation http://www.sapdesignguild.org/editions/highlight_articles_01/images/accomodation.png

  6. Disorders of optics of eye • Emmetropia (normal vision) • Myopia (short sightedness) • Corrected with negative power lens • Hyperopia ( Longsightness) • Corrected with positive power glasses • Presbyopia (age-related changes) • Range of accommodation depletion • Multifocal or bifocal lens correction

  7. Visual Abnormalities http://www.merckmanuals.com/professional/sec09/ch099/ch099a.html

  8. Retina/RPE/Choroid http://www.maculacenter.com/LightBox/glossaryImages/rpe.jpg

  9. Retinal Pigment Epithelium Crucial for the maintenance of photoreceptor excitability • The main functions of the RPE are the following: • (1) Transport of nutrients, ions, and water • (2) absorption of light and protection against photooxidation, • (3) reisomerization of all-trans-retinal into 11-cis-retinal, which is a key element of the visual cycle, • (4) phagocytosis of shed photoreceptor membranes, and • (5) secretion of various essential factors for the structural integrity of the retina.

  10. SUPER PROJECT • Nernst– Artificial Membrane • Diffusion of Ions • Is there a transport of water? • Stepper Motor – Servo System • Pusing in and pushing out fluid • Voltage Clamp • Using fixed voltage and determining how much to change to determine a transmission response • Fluid Flow • Voltage Clamp • Chamber • Artificial Membrane

  11. Artificial Membranes: How they are made? • Usual method is to have a 2 mm diameter hole in teflon sheet between aqueous solutions. Place 1 drop of (say) phospholipid in dodecane on hole and allow it to thin (as one would a soap bubble). Eventually get an optically black lipid bilayer film. Why use Artificial Membranes? • Calibration

  12. ‘Nernst’

  13. ‘Puddle’ • Stepper Motor – Servo System • Pushing in and pushing out fluid Sensor Engineered by David

  14. ‘Stepper’ • Stepper Motor – Servo System • Pusing in and pushing out fluid Engineered by David

  15. ‘Puddle 2’ - also using an artificial membrane

  16. RC-50 Imaging Ussing Chamber

More Related