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Anatomy and Physiology of the Retina Associate Professor Trevor Sherwin Department of Ophthalmology University of Auckland

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Page 1: Anatomy and Physiology of the Retina...Anatomy and Physiology of the Retina Associate Professor Trevor Sherwin Department of Ophthalmology University of Auckland. Light entering the

Anatomy and Physiology of the Retina

Associate Professor Trevor SherwinDepartment of Ophthalmology

University of Auckland

Page 2: Anatomy and Physiology of the Retina...Anatomy and Physiology of the Retina Associate Professor Trevor Sherwin Department of Ophthalmology University of Auckland. Light entering the

Light entering the Eye

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Page 3: Anatomy and Physiology of the Retina...Anatomy and Physiology of the Retina Associate Professor Trevor Sherwin Department of Ophthalmology University of Auckland. Light entering the

Eye Exam

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Page 4: Anatomy and Physiology of the Retina...Anatomy and Physiology of the Retina Associate Professor Trevor Sherwin Department of Ophthalmology University of Auckland. Light entering the

The retina

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Page 5: Anatomy and Physiology of the Retina...Anatomy and Physiology of the Retina Associate Professor Trevor Sherwin Department of Ophthalmology University of Auckland. Light entering the

Function of the retina

-Transmit electrical impulse to the brain via ganglion cells

- To absorb photons of light

- Translate light into a biochemical message

- Translate biochemical message into electrical impulse

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Page 6: Anatomy and Physiology of the Retina...Anatomy and Physiology of the Retina Associate Professor Trevor Sherwin Department of Ophthalmology University of Auckland. Light entering the

Sagittal section of the retina

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Page 7: Anatomy and Physiology of the Retina...Anatomy and Physiology of the Retina Associate Professor Trevor Sherwin Department of Ophthalmology University of Auckland. Light entering the

Cellular detail of the retina

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Page 8: Anatomy and Physiology of the Retina...Anatomy and Physiology of the Retina Associate Professor Trevor Sherwin Department of Ophthalmology University of Auckland. Light entering the

Octopus Retina

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Page 9: Anatomy and Physiology of the Retina...Anatomy and Physiology of the Retina Associate Professor Trevor Sherwin Department of Ophthalmology University of Auckland. Light entering the

Octopus Retina

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Page 10: Anatomy and Physiology of the Retina...Anatomy and Physiology of the Retina Associate Professor Trevor Sherwin Department of Ophthalmology University of Auckland. Light entering the

Layers of the retina

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Page 11: Anatomy and Physiology of the Retina...Anatomy and Physiology of the Retina Associate Professor Trevor Sherwin Department of Ophthalmology University of Auckland. Light entering the

Cell bodies and synapses

All vertebrate retinas are composed of three layers of cell bodies and two layers of synapses

Cell bodies of rods/cones

Cell bodies of bipolar cells

Cell bodies of ganglion cells

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Page 12: Anatomy and Physiology of the Retina...Anatomy and Physiology of the Retina Associate Professor Trevor Sherwin Department of Ophthalmology University of Auckland. Light entering the

Neuropil layers

Photoreceptor -bipolar synapse

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Page 13: Anatomy and Physiology of the Retina...Anatomy and Physiology of the Retina Associate Professor Trevor Sherwin Department of Ophthalmology University of Auckland. Light entering the

Neuropil layers

Bipolar – ganglion synapse

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Page 14: Anatomy and Physiology of the Retina...Anatomy and Physiology of the Retina Associate Professor Trevor Sherwin Department of Ophthalmology University of Auckland. Light entering the

Photoreceptors

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Page 15: Anatomy and Physiology of the Retina...Anatomy and Physiology of the Retina Associate Professor Trevor Sherwin Department of Ophthalmology University of Auckland. Light entering the

Photoreceptors

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Page 16: Anatomy and Physiology of the Retina...Anatomy and Physiology of the Retina Associate Professor Trevor Sherwin Department of Ophthalmology University of Auckland. Light entering the

Photoreceptors

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Page 17: Anatomy and Physiology of the Retina...Anatomy and Physiology of the Retina Associate Professor Trevor Sherwin Department of Ophthalmology University of Auckland. Light entering the

Rhodopsin and photoreceptor cells

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Page 18: Anatomy and Physiology of the Retina...Anatomy and Physiology of the Retina Associate Professor Trevor Sherwin Department of Ophthalmology University of Auckland. Light entering the

Rhodopsin

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Page 19: Anatomy and Physiology of the Retina...Anatomy and Physiology of the Retina Associate Professor Trevor Sherwin Department of Ophthalmology University of Auckland. Light entering the

Central and peripheral retina

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Page 20: Anatomy and Physiology of the Retina...Anatomy and Physiology of the Retina Associate Professor Trevor Sherwin Department of Ophthalmology University of Auckland. Light entering the

Central and peripheral retina

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Page 21: Anatomy and Physiology of the Retina...Anatomy and Physiology of the Retina Associate Professor Trevor Sherwin Department of Ophthalmology University of Auckland. Light entering the

Optic Nerve

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Page 22: Anatomy and Physiology of the Retina...Anatomy and Physiology of the Retina Associate Professor Trevor Sherwin Department of Ophthalmology University of Auckland. Light entering the

Optic Nerve

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Page 23: Anatomy and Physiology of the Retina...Anatomy and Physiology of the Retina Associate Professor Trevor Sherwin Department of Ophthalmology University of Auckland. Light entering the

Blood supply to the Retina

Choroid supplies 85%Mainly outer retinaPhotoreceptors

Central retinal artery supplies 15%Inner retinal layer

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Page 24: Anatomy and Physiology of the Retina...Anatomy and Physiology of the Retina Associate Professor Trevor Sherwin Department of Ophthalmology University of Auckland. Light entering the

IV Fluorescein Angiogram

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Page 25: Anatomy and Physiology of the Retina...Anatomy and Physiology of the Retina Associate Professor Trevor Sherwin Department of Ophthalmology University of Auckland. Light entering the

IV Fluorescein Angiogram

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Page 26: Anatomy and Physiology of the Retina...Anatomy and Physiology of the Retina Associate Professor Trevor Sherwin Department of Ophthalmology University of Auckland. Light entering the

IV Fluorescein Angiogram

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Page 27: Anatomy and Physiology of the Retina...Anatomy and Physiology of the Retina Associate Professor Trevor Sherwin Department of Ophthalmology University of Auckland. Light entering the

IV Fluorescein Angiogram

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Page 28: Anatomy and Physiology of the Retina...Anatomy and Physiology of the Retina Associate Professor Trevor Sherwin Department of Ophthalmology University of Auckland. Light entering the

The foveaFoveal pit + foveal slope + parafovea + perifovea

= Macula

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Page 29: Anatomy and Physiology of the Retina...Anatomy and Physiology of the Retina Associate Professor Trevor Sherwin Department of Ophthalmology University of Auckland. Light entering the

Eagle Vision

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Page 30: Anatomy and Physiology of the Retina...Anatomy and Physiology of the Retina Associate Professor Trevor Sherwin Department of Ophthalmology University of Auckland. Light entering the

Photoreceptor cell diameter

Rods (IS) – 2 microns

Cones (IS) – 6 microns

However, in the foveaCones (IS) – 1.5 microns

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Page 31: Anatomy and Physiology of the Retina...Anatomy and Physiology of the Retina Associate Professor Trevor Sherwin Department of Ophthalmology University of Auckland. Light entering the

Photoreceptor cell diameter

Rods (IS) – 2 microns

Cones (IS) – 6 microns

However, in the foveaCones (IS) – 1.5 microns

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Page 32: Anatomy and Physiology of the Retina...Anatomy and Physiology of the Retina Associate Professor Trevor Sherwin Department of Ophthalmology University of Auckland. Light entering the

Photoreceptor density

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Page 33: Anatomy and Physiology of the Retina...Anatomy and Physiology of the Retina Associate Professor Trevor Sherwin Department of Ophthalmology University of Auckland. Light entering the

Acuity of the retina

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Page 34: Anatomy and Physiology of the Retina...Anatomy and Physiology of the Retina Associate Professor Trevor Sherwin Department of Ophthalmology University of Auckland. Light entering the

The Macula Lutea

Xanthophyll caratenoids –zeaxanthin & luteinTapetum

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Page 35: Anatomy and Physiology of the Retina...Anatomy and Physiology of the Retina Associate Professor Trevor Sherwin Department of Ophthalmology University of Auckland. Light entering the

Colour Absorbancy

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Page 36: Anatomy and Physiology of the Retina...Anatomy and Physiology of the Retina Associate Professor Trevor Sherwin Department of Ophthalmology University of Auckland. Light entering the

Colour Blindness

Red/green colour blindness - X linked

Males only have a single X chromosome

Almost all genes on the X have no counterpart on the Y

Any gene on X, even if recessive in females will be expressed in males

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Page 37: Anatomy and Physiology of the Retina...Anatomy and Physiology of the Retina Associate Professor Trevor Sherwin Department of Ophthalmology University of Auckland. Light entering the

Summary of photoreceptors

Rods - Low light levels (scotopic)Peripheral visionSlow response

Cones - Visual acuityColour visionFast response

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Page 38: Anatomy and Physiology of the Retina...Anatomy and Physiology of the Retina Associate Professor Trevor Sherwin Department of Ophthalmology University of Auckland. Light entering the

Clinical examination of photoreceptors

Form & spatial vision, measured by visual acuityReflects rod & cone distribution

Colour vision testing is indicative of cone function and associated processing of the signal

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Page 39: Anatomy and Physiology of the Retina...Anatomy and Physiology of the Retina Associate Professor Trevor Sherwin Department of Ophthalmology University of Auckland. Light entering the

Vision and Movement

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