3.4 Clinical aspects of vision and hearing

Question 1

focusing problems

Answer 1

myopia (farsightedness) too long
hyperopia (nearsightedness) too short
perceptions = # of diopters
astigmatism: elliptical eye instead of round

Question 2

decreased transmission of light

Answer 2

corneal disease injury (cloudy cornea ) 
= fixed through grafting new one (no blood vessels) 
cataract (cloudy lens) 
= congenital at birth 
= secondary is eye disease 
= traumatic is injury 
= senile is with age 
= fixed though phacoemulsification (breaks lens and then sucks it out and the intraocular lens is inserted)

Question 3

Floaters

Answer 3

result of vitreus humour shrinkage
floaters = pieces of retina ripped off

treatment: enzymatic vitreolysis, lazer to chop floaters

Question 4

damage to retina

Answer 4

• diabetic retinopathy (swelling of capillaries results in bursting and bleeding into vitreus humour)
  treated with laster photocoagulation, or vitrectomy

macular degeneration (macula not regenerating (blurry focal vision) if caught early: photocoagulation

detached retina: retina detaches from epithelium, patch tear and then push back onto retina

Question 5

optice nerve damage

Answer 5

glaucoma (degeneration of nerve fibres at front of eye)
damage normally due to drainage issue of aqueous humour

closed angle block: humour going in (surgery)
open angle block: humour getting out (More common, fixed with medication)

can cause cupping (nerve compression)

Question 6

auditory deficit differences

Answer 6

air conduction, bone conduction - thresholds compared to check differences

Question 7

conduction hearing loss

Answer 7

air conduction shows loss of sensitivity (Bone is normal)

Question 8

sensory-neural hearing loss

Answer 8

both air and bone show loss of sensitivity, bone is same as air

Question 9

mixed-type hearing loss

Answer 9

bone is lower than air

Question 10

outer ear problems

Answer 10

congenial: atresia of auditory canal (Small pinnae)
trencher-collins syndrome (bone deformity)
aquired: blockage by object or earwax, external otisis

Question 11

middle ear problems

Answer 11

congenial: deformed ossicles
aquired: ruptured eardrum, ottis media, eustatchian tube malfunction, ostesclerosis, acute Ottis media, chronic Ottis media

Question 12

ostesclerosis

Answer 12

formation of spongy bone by welding stapes to oval window (stapedectomy)

Question 13

sensori-neural problems:

Answer 13

congenial: hereditary hearing loss, illness, accident, German measles (maternal rubella)

aquired; effect of noises, pesbycusis (degeneration through old age)

Question 14

central impairments

Answer 14

test results show sensory-neural damage

requires brain imagining for localization

Question 15

sensori-neural solution

Answer 15

cochlear implant: physically inputs electrical signal to neurons rather than condensing it through the cochlea

otherwise its surgery, medication, or get used to it