This video lecture covers ocular motility, specifically the difference between tropias and phorias. This is a simplified approach to detecting strabismus and documenting your findings. I’ve created an animatronic set of eyes out of cardboard to simulate these findings!
Misalignment that is always there, even when both eyes are open and attempting
to work together. Large angle deviations are obvious. If small angle, you can
detect it with the Cover-Uncover test.
Misalignment that only occurs some of the time, such as when the synchronization
between the eyes is broken by covering one eye. You can “break fusion” using
the Cross-Cover test.
Exotropia is when an eye turns outwards.
Esotropia is when an eye turns inwards.
Hypertropia is when an eye turns upwards.
Hypotropia is when the eyeball turns downwards.
Explaining the skull structure between horses and humans, and how this affects
the cardinal directions.
It helps to understand the ocular anatomy if you’re going to understand cardinal
directions of eye movement.
There are several ways to document large eye deviations. This is my preferred
method for large angle ductions.
This is another method to document eye tropias. On this scale, "0"
is normal, while "-4" is no movement.
The cover-uncover test is used to pick up small-angle tropias.
The cross-cover test (also known as the alternate cover test) is used to tease
out phorias. This works because you break fusion between the eyes.
Thank you Dr.Root
Your presentation is very helpful and simple as you usually do..
keep good work up and thanks again.
Comment by zen — November 10, 2010
Thanks, Dr. Root.
Comment by I Am Name — November 14, 2010
Thank you Dr Root for your good and scholar presentation
Comment by mortezashamsizadeh — December 14, 2010
Comment by feras mohdor — December 18, 2010
Dr.root a salute to u.wat an amazing job you have done.sir please continue to do this noble work by giving out these great informative and intereting lectures.thank you.hope to meet you some time in the future.thank you again
Comment by DR.root fan — January 5, 2011
GREAT PRESENTATION THANK YOU DR ROOT
Comment by sulay — June 21, 2011
This was a great works and did a a tremendous help in teaching our student to understand this topic.
Comment by Wahyu Raharja — June 29, 2011
In the frist I want say thank you for your lectures
I have a question when we do the glasses to the patient we but prism in front of the natural eye or in front of the eye in which have tropia
Comment by Anas — July 30, 2011
superb!!!! Simply the best
Comment by anshuman — August 13, 2011
Thank you so much.This’s very usefull for my study.
Comment by magnagiled — August 16, 2011
u r great sir. all dr teachers should like u. thank u very much
Comment by lovely — August 24, 2011
Thanks so much! Great video for distinguishing between phoris and tropias.
Comment by Jen — September 15, 2011
I learnt retinoscopy prety well with the help of your video and now the difference between Tropias and Phorias. Your explanations are simply simple. Thank you so much.
Sir, I wish to see a animated/live demo of usage of JCC (Jackson’s cross cylinder).
Thanking you once again.
Comment by Anant — October 11, 2011
Thanks a lot .
Comment by yasmine — March 23, 2012
Thank you!! I am a medical student and i now can totally understand tropis and phoria. hope i can make a Mandarin version in the future. Love your work~~!!
Comment by nichin — April 1, 2012
You spoke about double vision that comes from they eyes not being in alignment with each other… I have episodes of that too, but the thing that sets me apart is I have double vision in my left eye and sometimes triple vision in my right. I’m talking about when one or the other eye is completely closed and still each eye has multiple images, a primary and then some secondary one or ones… Can that really be from cataract like I was told by my eye doctor? I have been diagnosed with Ehlers Danlos type 3 and am afraid to get surgery til I feel confidant my eye doctor knows what’s going on. My eyesight gets worse then better then worse and it’s worrysome to say the least. Annoying as all get out too. I wish I could find more info on caratact surgery for Ehlers Danlos patients and am afraid of getting macular degeneration after the surgery so I’m just scared!