Aging and the Eye

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Aging and the Eye

• BIO 344

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Age-Dependent Changes

• Physiological and Performance

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Aging Eye
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General Aging Changes

• Mostly affect appearance
• Seldom affect performance
• Some need monitoring with age
• Lens
• Aqueous Humor
• Retina
• Macula

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General Aging Changes

• Sclera- thinner, pigment change
• Aqueous Humor- intraocular pressure ?
• Vitreous Humor- thins, opacity ?
• Cornea- arcus senilis (Ca and cholesterol),
  sensitivity ?
• Iris- muscles weaken, smaller pupil
• Lens size and thickness ?, elasticity ?
• Conjunctiva- dry eye ?

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More General Aging Changes!

• Retina- dulls, blood vessel changes
• Optic Nerve- boundaries less defined, fewer
  capillaries
• Macula- little or no foveal reflex, drusen and
  lipofuscin deposits, pigmentation ?
• Lids- orbicularis oculi muscle weakens
• Lacrimal Glands/Tears- production ?, ?
• Orbit- fat loss, enophthalmos

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Age Changes in Performance

• Refraction- lens and ciliary muscles
• Results in Presbyopia
• Age 40
• Acuity and Contrast
• Decreases after age 50
• Due to Brain
• Glare ?
• Due to lens and vitreous humor
• Dark
• Pupil and Lens

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More Performance Changes!

• Fun stuff- Vitreous Humor?
• Haziness
• Flashing Lights
• Moving Spots
• Color
• Discrimination ? as cones ?
• Dark
• Pupil and Lens
• Visual Field
• Size ? 1 to 3 degrees per decade

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Age-Related Changes

• Diseases and Syndromes

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Cataracts

• Symptoms increase in lens opacity
• Peripheral to nuclear
• Causes/Risk Factors
• UV light/free radicals
• Glycation
• Corticosteroids
• Diabetes

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Macular Degeneration (AMD)

• Macula
• Bruchs membrane and epithelium
• Two forms
• wet- 90
• Blood vessel rupture
• dry-
• Drusen deposits

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Normal ?
Dry AMD ?
? Wet AMD
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Glaucoma

• Intraocular pressure increases with age
• Damage to retina, optic nerve
• Types
• Open-angle shrinkage in width of field of view,
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• Angle-closure/ Narrow-angle between lens and
  cornea, rapid ? IOP
• Secondary due to other cause- diabetes, tumor,
  vessel disease

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Diabetic Retinopathy

• Cause diabetes mellitus
• Rapid increase in chance if diabetic for 15
  years
• Retinal vessels weakened by sorbitol? aneurysms?
  leakage? retinal damage
• Other complications, secondary glaucoma, retinal
  detachment

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Sources

• http//www.siggraph.org/education/materials/HyperV
  is/vision/eyebrain.htm
• http//www.uniteforsight.org/course/eyeanatomy.php
  
• http//www.allaboutvision.com/resources/anatomy.ht
  m
• http//www.merck.com/mrkshared/mm_geriatrics/sec15
  /ch126.jsp
• http//www.mayoclinic.com/invoke.cfm?idHQ00123
• http//www.amdhelp.com/whatis.asp
• http//www.ahaf.org/glaucoma/about/AqueousHumor.ht
  m
• http//www.ahaf.org/glaucoma/about/Aqueous_BuildUp
  .htm
• http//www.eyeweb.org/atlas/bdr_com.jpg
• http//www.eyecaresource.com