The Eye and Eye Diseases. STATS 19 SEM 2. 263057202. Talk 7.

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The Eye and Eye Diseases. STATS 19 SEM 2.
263057202. Talk 7.

• A.L. Yuille.
• Dept. Statistics. yuille_at_stat.ucla.edu

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Neural Prostheses.

• Forms of Neural Prostheses already used. (Simpler
  than last week). CNN story.
• Brain messages transmitted to nerve ends on
  pectoral muscles of the chest.
• Thoughts cause chest muscles to contract,
  activate prosthetic arm.

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Mike Mays and Others

• Project Prakash (light). Pawan Sinha (MIT).
• Sinha studies how childrens brain adapt to years
  of blindness followed by sight.
• Studies in India. Children have cataract surgery.
• Sinha Merely treating the eyes is not enough. No
  one knows if the visual modality will reclaim
  areas in the brain that it lost to other senses
  during blindness.
• Some patients commit suicide after recovered
  sight.

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Mike Mays and Others

• India has the worlds largest population of blind
  children. 100,000 children.
• 20 have Cataracts, which can be treated.
• Poverty, inter-marriage to blind relatives, diet,

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Mike May and Others.

• Mondloch (McMaster).
• Children with cataracts in the left-eye, can
  recognize faces after surgery.
• Children with cataracts in the right-eye, cannot.
  
• But probably too late if surgery happens 2 months
  after birth.

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Brain-imaging.

• Brain imaging (FMRI) show that neural areas in
  the brain devoted to vision can perform different
  functions for the blind.
• Vision area Touch area.
• Increased activity in the Visual Cortex when
  blind subjects read by using Braille.
• Areas of the Visual Cortex get activated when
  blind patients remember words and do other verbal
  memory tasks. (Normal subjects use language
  areas).

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The Big Three Eye Diseases.

• Cataracts
• Glaucoma
• Age-Related Macular Degeneration.

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The Eye

• Anatomy.

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The Eye

• Imaging and the Lens.

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The Eye

• Photoreceptors Rods and Cones.

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The Eye

• Where things go wrong
• (I) The Lens (focuses light).
• Lens structure can change. (Cell growth, protein
  changes). Cataracts.
• (II) Eye contains fluids. The pressure of the
  fluid can get high (insufficient drainage). This
  affects nerve cells. Glaucoma.
• (III) Retina failure. Age-Related Macular
  Degeneration.

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Cataracts.

• With age, the Lens enlarges and the protein
  structure changes (e.g. lens can go yellow). Most
  people over 65 have some cataracts.
• Symptoms Poor distance vision, blurred vision,
  frequent prescription changes, poor night
  vision, glare, halo around lights, double vision.

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Cataracts.

• The Lens.

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Cataracts.

• Risk Factors
• Age, Diabetes, Women/Men, Race, Developing
  countries near the Tropics, Hereditary, Smoking,
  Some Medications, Excessive sunlight.
• Second sight vision appears to get better, but
  then gets far worse.

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Cataracts

• Surgery is Effective. (These days).
• Glass is well-tolerated by the Eye (2nd World
  War).
• Remove parts of Lens (by Microsurgery).
• Implant plastic.
• Outpatient go home the same day.

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Glaucoma

• Glaucoma silent thief of vision.
• Very difficult to detect. Accounts for 12 new
  blind cases in the US each year.
• Start by gradually losing peripheral vision. This
  causes irreversible damage.
• Regular Eye exams. Diagnose pressure in the eyes.

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Glaucoma

• Glaucoma is a collection of different eye
  problems.
• All raise the pressure of liquid inside the eye.
• The Eye is basically hollow, like a balloon. It
  contains fluid that helps keep its shape.
• New fluid comes in, old fluid is drained out.
• But sometimes the drain gets blocked raises
  fluid pressure, damages the optic nerve
  (irreversible). Glaucoma.

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Glaucoma

• Draining.

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Glaucoma

• Recall, the image is formed by the Rods and Cones
  on the retina.
• These send nerve impulses to the brain via the
  Optic Nerve. The Optic Nerve starts at the Optic
  Disk.
• High fluid pressure in the Eye damages the Optic
  Disk. Exact mechanism is unknown.
• Peripheral vision is often lost before patients
  are aware of it.

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Glaucoma

• Optic Nerve.

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Glaucoma

• Treatment.
• Lower the fluid pressure.
• Eye drops, drugs, lasers, surgery.
• Risk factors Age, Hereditary, Race (African
  Americans).

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Age-Related Macular Degeneration.

• Least understood.
• Ageing of the outermost layer of the Retina.
• Progressive degenerate changes in the epithelium
  cells, photoreceptors (rods and cones).
• Major cause of blindness in US, England, Canada.

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Age-Related Macular Degeneration.

• Cells on retina.

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Age-Related Macular Degeneration.

• Risk Factors.
• Women/Men, Heredity, Blue eyes particularly
  Caucasians, smoking, high blood pressure,
  sunlight.
• Treatment is limited. Some forms respond to
  lasers, surgery,

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General Health Care.

• Diabetes major cause of blindness among working
  people in US.
• Increases risk for Cataracts and Glaucoma. But
  also damages the retina directly.
• Main risk factor for Diabetes high blood sugar.

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General Health

• High-Blood Pressure (Hypertension). Damages the
  blood arteries in the retina.
• AIDS/HIV. Affects the immune system.
  Microorganisms CMV (Cytomegalovirus).
• CMV attacks the retina of about 30 people with
  AIDS. Destroys tissue, causes bleeding, retinal
  detachment.

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Alan Scott and Botox

• Botox was developed by an Eye Surgeon Alan
  Scott.
• It is used to relax eye muscles and allow eyes to
  track objects.
• He sold the idea to a company for development.
  Later, the company realized that Botox could be
  used for cosmetics.

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Traditional Low-Vision Devices.

• Low tech.
• Hand-held magnifiers.
• Telescopes.

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Summary

• Review of the Eye.
• Three Major Eye Diseases Cataracts, Glaucoma,
  Age-Related Macular Degeneration.
• First two treatable, if Glaucoma detected early
  enough.
• Major advances in treatment.