Thursday, July 31, 2014

August 2014 Strabismus Rounds

This is our first strabismus rounds for the year. I'll present 3 recent cases that have gone to the OR, and your job is to come up with a surgical plan for each and submit it in the comments section. The new twist for this year: you will demonstrate your ability to perform the surgery in the wet lab. So prior to the session, pick a case and a few friends, go to the wet lab, and record your surgical correction with the appropriate model.


Case 1: This is a 10 month old boy who has had crossed eyes since birth.




He cross-fixates, and does not object to occluding either eye. His ocular exam is otherwise normal, and his cycloplegic refraction is +1D in both eyes. His alignment is stable from his initial exam 2 months ago. You estimate he is ET 40 by Krimsky. What is your surgical plan?


Case 2: This is a 12 year old girl who has been concerned about her friends noticing her eye drifting.





You find her acuity to be 20/20 in both eyes without correction. Her X(T) measures 45PD, she becomes tropic spontaneously, and will often remain tropic through a blink. Her stereoacuity has decreased over the past 6 months from 40 sec to 200 sec. What is your surgical plan?


Case 3: This is a 7 year old girl, who had surgery for esotropia when she was 8 months old. For the past year, she has been turning her face to the right, and sometimes adopting a small tilt to the right.


Her acuity is 20/20 in both eyes without correction. You measure LHT 6 in forced primary gaze, LHT 15 in right gaze, Ortho in left gaze and downgaze. Her LHT increases on left head tilt. What is your surgical plan?

Friday, October 11, 2013

October 18 session

We'll be covering the chapters on Vertical and A- and V-patterns strabismus in an interactive session.
The link to the Brainshark is here.
As usual, 1st years review the chapter and lecture and send questions my way- either comment on the blog, or e-mail me. 2nd years should pull a relevant article and circulate it to the group prior to the session. 3rd years prepare a 5 minute teaching session for us.

I'll be doing a traditional lecture/webinar on the chapter on Special Forms of Strabismus. The slides (without audio) are here.

The link to the webinar is here

Monday, September 23, 2013

Exotropia webinar

For those who missed the exotropia talk in the classroom, the recording can be found here.

Friday, September 13, 2013

September 20 lectures

We will be covering Esotropia and Exotropia this week.

Both talks are on Brainshark:

Exotropia

Esotropia

The Exotropia talk has no audio- I will cover it in class as a webinar and add the link afterwards.

The Esotropia talk has audio. In class, we will have an open discussion about the work-up and management of ET:

Each 1st year should review the chapter in BCSC and review the Brainshark presentation. Add any questions or areas that need clarification in the comment section of this blog.

Each 2nd year should pull an article on esotropia, send it to all of us, and prepare a 2-3 minute "digest" of its clinical relevance.

Each 3rd year should create a 3-5 minute teaching session on some aspect of esotropia.


Wednesday, March 27, 2013

4/3/13 Cases

Case 3

36 y/o man with longstanding strabismus, concerned that left eye "goes off" and he has trouble in social situations.
No prior eye surgery or patching. Specs for myopia.

Exam:

Va cc 20/20 ou

Rotations: Trace limitation to elevation in adduction OD

Alignment:
R gaze: LHT 8    Primary: LHT 12     L gaze: LHT 15

Double Maddox Rod: No torsion ou

Worth 4 dot: Suppresses left eye distance and near

Stereo: Nil

Displays a left head tilt ~5-10 degrees

Photos:


Questions:

Q 3.1 What is your working diagnosis? Are there additional tests that may help confirm your diagnosis?

Q3.2 What is your surgical plan?





Case 4

42 y/o woman with 2 day history of left-sided numbness (face, arm, torso, leg) and bilateral dysacusis, presents with "right eye turning in."
MRI shows 1.2 cm ring-enhancing lesion of  the right pons consistent with tumefactive demyelination.
Remote history of subfoveal CNV OD secondary to ocular histoplasmosis, had submacular surgery with no recurrence.

Exam:

Va cc: 20/400 OD (central scotoma stable), 20/20 OS

Rotations: Severe limitation to abduction OD

Alignment:
R gaze: ET 45     Primary: ET 25     L gaze: ET 4

Ocular exam: Stable 2+ NS, foveal RPE atrophy; optic nerves pink and flat ou with no RAPD

Photos:
Upper photo: Left gaze; Lower photo: Attempted right gaze   
Representative photo from http://bingskee.hubpages.com

Questions

Q 4.1 Assuming her alignment is stable in 4-6 mos, what is your surgical plan?





Tuesday, February 19, 2013

2/15/13 Case Summary

We discussed Cases 1 and 2 during a webinar last Friday. The presentation is saved at:
http://meet79792352.adobeconnect.com/p516enlgmqt/
Some of the audio is involved with the formatting and use of smartphones and tablets to answer the questions.

Summary of Case 1:









The patient has a sensory extropia secondary to traumatic optic neuropathy and correction can involve right lateral rectus recession and right medial rectus resection. Patients with one poor-seeing eye usually prefer to have surgery on that eye, and usually that is feasible.

There are some cases where the plan with the higher likelihood of success involves operating on the better seeing eye. In those cases, I try to explain to patient (or parent) how their goals are more likely to be achieved with surgery on the sound eye, and what to expect if surgery is only performed on the unsound eye. If they decide to only operate on the poor eye, then I operate on that eye only.




Summary of Case 2:
















An intermittent hypertropia implies an early onset, which can be important when evaluating a patient with a "new" vertical deviation- if they are fusing a hypertropia >5PD, it's probably not an acute process.

The management of 4th nerve palsy with or without inferior oblique overaction has a number of options, determined by assessment of versions, torsion, head osition, and patient age. A general rule of strabismus surgery planning is to operate on the muscles with a field of action on the direction where the deviation is greatest. In this case, the left hypertropia is worse in right gaze, so the options are to work on the vertical recti of the right eye, or the obliques of the left eye.

Left inferior oblique myotomy/recession would correct the inferior oblique overaction and up to 12-15PD of hypertropia. It will have a modest incyclorsion. I've found a myotomy works well in children, but may leave residual deviations in adults. Myotomy is not adjustable; recession can be adjusted.

Left superior oblique tuck will improve the ability to depress in adduction, so can be considered in cases with moderate to severe superior oblique underaction. It will result in a large incyclorotation and may cause a Brown syndrome if the tuck is too tight. A tuck is not easily adjusted.

Left superior oblique Harada-Ito can cause a moderate to large incyclotorsion with minimal effect on vertical alignment. The procedure can be used as a solitary procedure for isolated torsion, or combined with other vertical muscle surgery. The Harada-Ito can be adjusted.

Right inferior rectus recession works well in adults and is easily adjusted. It can result in a moderate incyclotorsion, especially if it is displaced nasally. Inferior rectus recession should be avoided if there is minimal (or no) hypertropia in downgaze, as it may cause the hypertropia to "flip" in downgaze with difficulty reading post-operatively.

Tuesday, February 12, 2013

2/15/13 Cases


Here are two cases that we will be discussing during a webinar session 2/15/13. Both cases have had surgery for their strabismus. Your assignment is to review the clinical history and images, develop a surgical plan, and post your plan and reasoning in the comments section. You don't need to worry about specific surgical dosages, but should indicate which muscle you plan to work on, and whether you will weaken, strengthen, transpose, or otherwise modify the muscle.

I will moderate the comments and "publish" them after our session with a summary of our discussion. Please separate your comments into Case 1 and Case 2.


Case 1:
5y/o boy, history of shaken baby syndrome and optic atrophy OD>OS.
Va 20/200 OD, 20/40 OS. + RAPD OD
20ft: XT 40
13in: XT 35
Strongly prefers fixing with OS. Full versions. Mom wants his right eye to be straight before he enters kindergarten.


Representative image from healthinset.com

Questions:

Q1.1 What is your surgical plan?



 Case 2:

7y/o girl brought in by mother because "eyes look funny". No prior injuries or surgery. Mom notes that patient has always tilted her head to the right.
Va 20/20 OU
Rotations: 2-3+ LIOOA
Primary: LH(T) 12
R gaze: LHT 15; L gaze: LHT 4
Down: LHT 6

L gaze
Questions:
Q2.1 What measurements would you expect on head tilt to the right and left?
Q2.2 What would you expect with double Maddox rod testing?
Q2.3 What is your surgical plan?