ASSESSMENT OF ACCOMMODATION
ACCOMMODATIVE SKILLS
a. amplitude
b. facility
c. accuracy
d. sustainability
e. consistency
f. interactivity
AMPLITUDE OF ACCOMMODATION
1. DONDER'S PUSH UP
a. minimum amplitude = 15 - .25(age in years)b. monocular vs. binocular
c. overall low sensitivity in non-presbyopes
2. MINUS LENS METHOD
a. binocular = PRA
1. +2.00/-2.00 lens facility
a. 40 cms with 20/30 size targetb. 60 sec duration
c. monocular
d. binocular with suppression checks
e. expected
i. 10-11 cycles / min monocularii. <3-4 definitely abnormal
f. observations
i. OD vs. OSii. monocular vs. binocular
iii. decreased rate over time
2. near-far fixation facility
a. 20/20 distance letterb. 40 cms or closer 20/20 letter
c. expected
i. should be instantaneousii. any delay is abnormal
(stimulus vs. response function)
can be considered the gain of accommodation
lag of accommodation
1. MEM retinoscopy
a. 40 cms or less fixation distanceb. age appropriate reading material
c. OD & OS concurrently
d. loose lenses for neurtralization
e. very brief observations
f. observe both principal meridians
g. expected
i. between +0.50 and -0.25
2. FUSED CROSS CYLINDER
a. an excellent tool for presbyopesi. predictable and linear responsesii. accommodation remains stable
b. not a pure lag measurement in non-presbyopes
ii. accommodation responds to the neutralizing lenses
3. KINETIC COVER TEST
a. combines cover test and NPC-like target movementb. constant dissociation leads to more accurate accommodative responses
i. Point A : 40 cm alternate cover test amplitudeii. Point B : 5 cm alternate cover test
iii. Point C : 40 cm alternate cover test amplitude
c. interpretation
i. positive KCTPoint C cover test amplitude >=5 pd eso relative to Point Aii. negative KCT