Jai Mata Di The Mechanism for Defocus-driven Occular Growth
description
Transcript of 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
Power (Diopters) focal length (metres)
1 D 1 m2 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
Lens
http://www.math.ubc.ca/~cass/courses/m309-01a/chu/MirrorsLenses/lenses.htm
Lens Accommodation
http://www.sapdesignguild.org/editions/highlight_articles_01/images/accomodation.png
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
Disorders of optics of eye
Visual Abnormalities
http://www.merckmanuals.com/professional/sec09/ch099/ch099a.html
Retina/RPE/Choroid
http://www.maculacenter.com/LightBox/glossaryImages/rpe.jpg
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.
Retinal Pigment Epithelium
SUPER PROJECTNernst – 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
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.
Artificial Membranes: How they are made?
Why use Artificial Membranes?Calibration
‘Nernst’
‘Puddle’Stepper Motor – Servo SystemPushing in and pushing out fluid
SensorEngineered by David
‘Stepper’
Engineered by David
Stepper Motor – Servo SystemPusing in and pushing out fluid
‘Puddle 2’ - also using an artificial membrane
RC-50 Imaging Ussing Chamber