Introduction to Ocular Motility Extraocular Muscles EOM ...

1.
Cover-Uncover Test
Observe eye movement as the
unoccluded eye recovers fixation.
Esotropia Esotropia - Eye pulls out
Exotropia Exotropia - Eye pulls in
Hypertropia Hypertropia - Eye pulls down
Hypotropia Hypotropia - Eye pulls up
Left hypotropia. OD fixing.
3.
Cover-Uncover Cover Uncover Test
Test - Vertical
Vertical
Right Hypertropia. OS fixing.
2.
4.
Cover fixing eye (OD)
Hypotropic OS pulls up.
OD under cover deviates up.
Cover fixing eye (OS)
Hypertropic OD pulls down
OS under cover deviates down
Measuring the deviation
Use PACT if possible
Use Krimsky if patient cannot fixate well.
If only one eye moves - place prism in front of eye
with restricted motion.
1.
3.
Cover-uncover test: Esotropia
LET. OD fixing.
Cover is removed.
Neither eye moves.
Bifovial fixation
2.
4.
Cover deviated OS.
OD does not move.
Cover fixing eye.
Deviated OS pulls out.
OD under cover deviates in.
Cover-uncover test: Exophoria
1. 2.
3.
Cover is removed, deviated
eye moves in to regain fusion.
Cover left eye.
Eye under cover deviates out.
Measuring Strabismus
4.
Cover right eye.
Eye under cover deviates out.
PACT - Prism Alternate Cover Test
Most accurate, requires good fixation
Hirschberg and Krimsky
If poor vision, poor fixation, nystagmus
Young children, inattention
Maddox rod
useful for measuring small vertical deviations
in cooperative patient.
8