General Anatomy of the Eye

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General Anatomy of the Eye Degenerative
Diseases of Human Retina

• Jennifer Hsieh
• Psy 159
• Physiological Basis of Perception
• 1/11/2005

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Background
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Key Terms

• Vitreous humor fluid in major chamber of eye.
• Retina encodes the info as a neural signal to
  transmit to the brain.
• Macula lutea pigmented central region of the
  retina containing fovea.
• Fovea greatest capacity for fine detail
  discrimination.
• Optic nerves bundle of ganglion cell axons
  carrying visual info.
• Cornea where light enters the eye.
• Iris a smooth ring of muscle with a central
  opening.
• Pupil central opening.
• Lens helps the cornea to produce a focused
  image.

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Anatomy of the Retina
Photoreceptors  (Rods and Cones) Outer
Plexiform Layer Inner Nuclear Layer   Inner
Plexiform Layer  Ganglion Cells 
R
H
B
A
G
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The Retina

• Receptors absorb photons begin to create
  neural signals.
• Outer plexiform layer the receptors terminate
  here.
• Inner nuclear layer -
• Horizontal cells responsive to lights across a
  wide area of the retina.
• Bipolar cells response can be either
  hyperpolarizing (light falling directly on it) or
  depolarizing (light falling to the side).
• Amacrine cells produce response (transient /
  phasic) when the light level changed.
• Inner plexiform layer signals within bipolar
  cells conducted to here.
• Ganglion cells receive the end products of all
  the previous processing and communicate it to the
  brain.

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Retinal Photo - Ophthalmoscope
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Degenerative diseases of the human retina

• In some eye diseases, the retina becomes
  compromised, and the degenerative changes lead to
  serious damage to the nerve cells that carry the
  messages about the visual image to the brain.

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Age Related Macular Degeneration
Age related macular degeneration - the macular
area and fovea become compromised due to the
pigment epithelium behind the retina degenerating
and forming white spots.
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Glaucoma
Glaucoma - the pressure within the eye becomes
elevated. The pressure rises because the anterior
chamber of the eye cannot exchange fluid properly
by the normal aqueous outflow methods.
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Retinitis Pigmentosa
Retinits pigmentosa - a hereditary disease of the
retina. Most of the faulty genes affect the rod
photoreceptors. Characteristic pathology is the
occurrence of black pigment in the peripheral
retina and thinned blood vessels.
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Diabetic Retinopathy
Diabetic retinopathy - a side effect of diabetes
that can cause blindness. The vital nourishing
blood vessels of the eye become damaged,
distorted and multiply in uncontrollable ways.
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Now that we are done, take the quiz!

• 1. The _____ transmits electrical impulses from
  the eye to the brain.A. LensB. Optic nerveC.
  Vitreous humor
• 2. The eye works a lot like a...A. CameraB.
  ComputerC. Projector
• 3. Below is a view of the fundus of the retina in
  a patient with ______.
• A. Glaucoma
• B. Healthy Eye (Normal)
• C. Macular degeneration

B
A
A
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References

• Hagerman, G.S. and Johnson, L.V. (1991) The
  photoreceptor-retinal pigmented epithelium
  interface. "Principles and Practice of Clinical
  Electrophysiology of Vision" (Eds. Heckenlively,
  J.R. and Arden, G.B.) Mosby Year Book, St. Louis,
  1991, pp. 53-68.
• Henkind , P., Hansen, R.I. and Szalay, J. (1979)
  Ocular circulation. In "Physiology of the human
  eye and visual system" (Ed. Records, R.E.) pp
  98-155. Harper Row, new York.
• Kolb, H. (1991) The neural organization of the
  human retina. In "Principles and Practices of
  Clinical Electrophysiology of Vision" (Eds.
  Heckenlively, J.R. and Arden, G.B.) Mosby Year
  Book Inc. , St. Louis, pp. 25-52.
• Polyak, S.L. (1941) The Retina. University of
  Chicago Press, Chicago.
• Van Buren, J.M. (1963) The retinal ganglion cell
  layer. Charles C. Thomas, Springfield, Illinois.

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THANK YOU