SENSORY DECLINE: EYE AND EAR

What is Presbycusis?

Hearing loss due to primary aging, experienced by 50% of 60-79yo’s.

Manifests slowly as the lateral loss of high pitch sounds.

• As the level of pitch lowers, the ability to understand speech is impaired.

What typically causes presbycusis?

Sensioneural Hearing Loss; damage to the sensory hair cells of the cochlea, characterized by decreased perception of sound and music.

Treated through hearing aids and cochlear implants.

What is Tinnitus?

Hearing sounds without the proper stimuli. In the form of rings, buzz’s, whistling.

• Caused by numerous factors and is multi-morbid; medications, caffeine, high sat, high stress, low BP.

What is central presbycusis?

An impaired processing of the neural stimuli associated with hearing. Influences the interpretation, recognition, and processing of hearing.

• Associated with neurodegenerative diseases like dementia.

How does aging change the eye? (Physical changes)

1. Stiffening of the lens influences refraction.

2. Rigidity and flattening of the cornea influences astigmatism.

3. Sceral, pupil, and iris degeneration.

4. Reduced density of retinal cells influences transduction - longer identification response to visual stimuli.

Accumulate due to both primary and secondary components of aging; UV exposure, chemicals, aging, temperature, etc.

What is Presbyopia?

A type of primary aging seen as a loss of the eyes ability to focus on close objects. Due to a stiffening of the lens, where the lens can’t refract as easily onto the retina.

• Begins in 40’s and is progressive.

• From a lack of terminal differentiation of cells, elasticity (loss of collagen), and smooth muscle cells.

What are cataracts?

A pathological condition whereby crystallin (protein) misfolds and aggregates, causing opaqueness in the lens.

• Visible cloudiness in the eye.

Causes haziness, blurred vision, low acuity, decreased sensitivity to low contrast environments.

Treated through surgery, where the lens is replaced with a prosthetic. Can also help correct presbyopia.

What is Macular Degeneration?

The most common source of severe vision loss in individuals 50yo+, because there are no reversible or preventable pathways.

Affects central field of vision, and ability to see fine details.

What is the macula?

A part of the retina that contains the fovea. Images are focused here due to the high density of rods and cones.

What is the macula?

A part of the retina that contains the fovea. Images are focused here due to the high density of rods and cones.

What is Glaucoma?

Progressive damage to the optic nerve, due to high intraocular pressure. Onsets as a loss of peripheral vision (opposite to macular degeneration).

• Leads to permanent vision loss and blindness.

Glaucoma is treated through eye drops that relieve pressure.

What are the two types of glaucoma?

Open-Angle Glaucoma: a slow onset.

• When the pressure slowly damages retinal and optic nerves.

Closed-Angle Glaucoma: an acute and rapid onset.

• When fluid is suddenly blocked and rapidly raises pressure. Characterized by severe pain and blurred vision, seeing halo’s.

What is Diabetic Retinopathy?

When chronic high blood pressure associated with diabetes damages and bursts the blood vessels of the eye.

Initially; micro aneurysms form and absorb into the retina causing blurriness.

Over time; Capillaries leak fluid and cause retinal edema.

Later; Growth and burst of blood vessels cause hemorrhaging, leading to to blindness.