Lecture 10 accommodation Flashcards
Should you use WNL when recording accommodation?
NO we never looked!
is the process whereby the dioptric power of the crystalline lens changes so that an in-focus retinal image can be maintained on the fovea
–describes (normal/abnormal) accommodation?
normal
Accommodation is (non/consensual) and usually (unequal/equal)
consensual, equal
What is part of the near triad in accommodation?
convergence, miosis, accommodation
-Tension on ciliary muscle released
-Capsule flattened
-Decrease in dioptric power
describes (negative/positive) accommodation
negative
PSNS stimulated A. Ciliary contraction B. Ciliary body moved forward C. Ligament tension released D. Lens becomes more convex Increase in dioptric power describes (negative/positive) accommodation
positive
invertebrates have (no/positive/negative) accommodation
no
amphibians have (no/positive/negative) accommodation
positive
fish (no/positive/negative) accommodation
negative
humans have (no/positive/negative) accommodation
both positive and negative
T/F birds have much better accommodation than humans
T
-Depends on the tone of the ciliary body
Strongly controlled by convergence and fusion
-Darkness removes the appreciation of blur
-Somewhat controlled by the shift of spectral sensitivity and chromatic aberration
-“Standby” position of the lens in the dark
-Night myopia or empty field myopia
is which kind of accomodation: A)Reflex accommodation B)Tonic Accommodation C)Convergence-Accommodation D)Psychic or Near Accommodation
tonic accommodation
- Stimulated by the quality of retinal images
- Blur signals or defocus signals
- PSNS pathway: CN 3 to short posterior ciliary nerves to the ciliary body, increases power of lens
is which kind of accomodation:
A)Reflex accommodation
B)Tonic Accommodation
C)Convergence-Accommodation
D)Psychic or Near Accommodation
reflex accommodation
- Also known as relative accommodation
- As the convergence angle is changed, the accommodation must increase to see a target nearer and nearer
- Ratio of Convergence Accommodative to -convergence: CA/C
- Low illumination and low CA/C ratio are strong drivers for near work induced myopia*
is which kind of accomodation:
A)Reflex accommodation
B)Tonic Accommodation
C)Convergence-Accommodation
D)Psychic or Near Accommodation
convergence accommodation
-Accommodation induced by the awareness of -nearness of target
-Microscopes
-Auto-refractor
-Eyestrain
-Charts less than 20ft
is which kind of accomodation:
A)Reflex accommodation
B)Tonic Accommodation
C)Convergence-Accommodation
D)Psychic or Near Accommodation
psychic accommodation
T/F when accommodation is changed , convergence is also changed
T
When measuring accommodation you use (minus/plus) lenses to induce accommodation
minus
When measuring accommodation you use (plus/minus) lenses to relax accommodation
plus
(lead/lag) is slighly more than is needed when measuring accuracy of accommodation
lead
(lag/lead) is slighly less than is needed when measuring accuracy of accommodation
lag
Most normal people show a (lead/lag) of about +0.50D
lag
T/F in normal accommodation sustained reading of about 40 cm should be at least 2 hours
T
T/F In normal accommodation it is expected for there to be a intermittent accommodation at 5-8’’ for short periods of time
T
T/F in donders table there is a increase in amplitude of accommodation with increase in age
F There is a decrease in amplitude of accommodation with increase in age
At age 40 their is an expected amount of amplitude of accommodation of \_\_ A)15 B)6.5 c)4.5 d) 7.5
4.5
Hofstetter’s formuli
is the _(average/maximum/minimum)__ expected accommodative amplitude:18.5-(0.30)(age)
Average
- average expected accommodative amplitude
- Maximum expected accommodative Amplitude
- Minimum expected accommodative amplitude
a.18.5-(0.30)(age)
b.15-(0.25)(age)
c.25-(0.40)(age)
match them to correct formula
Maximum expected accommodative Amplitude= 25-(0.40)(age)
Minimum expected accommodative amplitude= 15-(0.25)(age)
Average expected accommodative amplitude= 18.5-(0.30)(age)
Hofstetter’s formuli
is the _(average/maximum/minimum)__ expected accommodative amplitude:25-(0.40)(age)
maximum
Hofstetter’s formuli
is the _(average/maximum/minimum)__ expected accommodative amplitude: 15-(0.25)(age)
minimum
when using +/- 2.00 flipper you want to note how many ____ per minute the pt can see (with/wihtout) blur
cycles, without
If less than 8cpm with flipper of +/-2.00 that the pt can see without blur you want to repeat test(binocularly/monocularly)
monocularly
__ flips equals 1 cycle
2
Inability to relax from the accommodative lead, some of which is experienced by the patient as an interference with distance vision
–describes what accommodative (excess/spasm/insufficiency)
spasm
Children 8-12 years old will have a \_\_ cpm binocularly/ \_\_cpm monocularly A)5 -7 B)6-8 c)4-5 d) 7-8
5-7
Adults 13-30 y: \_\_ cpm binocularly/\_\_ cpm monocularly A)10-11 B)11-13 c)4-5 d) 7-8
10-11
Monocular findings should be within \_\_cpm for each eye. A)5 B)6 c)4 d) 7
4
-The lag is abnormally high
- e.g. 5D accommodation is required, yet 4D is the accommodative response (less)
(1/5=.20 1/4= .25)
-The response is reduced for the patient’s age
- Clearing additional minus power at near is difficult for this patient
- -describes what accommodative (excess/spasm/insufficiency)
Accommodative Insufficiency
Abnormally high lead, e.g. 5D accommodation required, yet the accommodative response is (more) 5.75D.
Usually seen in younger patients.
Clearing additional plus lens power is difficult for this patient.
Accommodative Excess
