Dr. Silvia Moguel-Ancheita is a Strabismologist, Ophthalmological Doctor, Master in Neurosciences & a
Master in Research Ethics. While Dr. Moguel-Ancheita’s Master in Neurosciences is from the Pablo De
Olavide University, Spain, her Masters in Research Ethics, Third Level is from the University of Hong
Kong. She is the High Specialty Headline Professor in Strabismus at the Universidad Autonoma De
Mexico, in addition to being a Professor of Neurostimulation and Neurofacilitation at the Sociedad
Mexicana De Pediatria. She is also the Ex-President of the Centro Mexicano De Estrabismo, the Current
Counselor of Centro Mexicano De Estrabismo & is also a Member of the International Strabismological
Association. She is also a Member of the European Strabismological Association, in addition to being a
Member of Consejo Latinoamericano De Estrabismo. Dr. Moguel-Ancheita is the Coordinator of the
Amblyopia Commission & also Heads the Amblyopia Campaign. She is a Member of the Panamerican
Ophthalmology Association, & has been Heading the Strabismus Department for the past 20 Years at the
National Medical Center “20 De Noviembre”, Issste. She is a Member Certified by the Mexican Council of
Ophthalmology, in addition to being the Revisor of the Archivos Magazine of the Spanish Society of
Ophthalmology. Dr. Moguel-Ancheita is a Member and Revisor of the Editorial Committee of the
Mexican Journal of Ophthalmology & has more than 432 Papers, 230 Courses, 84 Publications, 20 Thesis
Advisor, 6 Magistral Conferences & even 4 Honorary Mentions.

1) How would you address diplopia in this case?
Eye Muscle Surgery
I can see that it is a case with exophthalmos and significant eye movement restriction, despite having undergone a decompression operation. In the images I can still see signs of inflammatory activity, however I must assume that the activity has already been verified through autoimmune tests and antibody levels, because only under autoimmune stability I would decide the surgery for strabismus. If not, and the patient persists in the autoimmune active phase, I would prefer treatment with botulinum toxin.

2) If you would operate, what procedure would you choose?
Both eyes MR + right IR recession
As normally occurs, the inferior and medial rectus muscles are the most common of affectation in thyroid disease; although the degree of infiltration may be occurring asymmetrically and irregularly even in all muscles, it is more common to observe hypotrophies and esotropias. It is also one of the most frequent strabismus after decompression surgery. And since the most common cause is related to a greater tension of these, the initial indication is to weaken them, which is why I prefer the bilateral weakening of both medial rectus and to initially add the recession of the right inferior rectus, taking into account that the left one may require it in another time.

3) What would you do further for his diplopia?
Additional Surgical Procedure
As we can see, surgery in thyroid strabismus, even when planned correctly, may not have the expected response. It must be considered that strabismus, in this case, is caused by all orbital disorders, including the posterior tissues, that impede the good functionality of the muscles, as well as the structural loss of the muscle fibre, damaging both its elasticity, its contractile force, and even the loss of affected tendon supports after decompression, etc. So we have to re operate. Either to add further weakening, if we can see that the previous was not enough, or even to consider the resection of the lateral rectus, which can be evaluated with topical anaesthesia.

4) Would You Opt for Adjustable or Fixed Suture Surgery? & Why?
The final result in this case is extremely good and demonstrates the possibility of the use of reinforcement techniques that are normally less recommended in surgery for thyroid strabismus. Personally, I prefer to do the second surgery under topical anaesthesia, trying to make it a little undercorrected. Doing the surgery under topical anaesthesia is a good procedure to evaluate the muscle function, allows observing the immediate effect when the muscle has been removed and it also allows evaluating the final position and the effect on the entire strabismus.
I would not have done fixing techniques.

5) What According to You (if any) is the Role of Transposition of IR Muscle While Recessing it?
I agree on transposition of the inferior recti when they are tense and this can bring improvement over the horizontal deviation; I have used it especially in cases of congenital fibrosis of both inferior rectus as in CFEOM type I.

6) What is the Role of Traction Test for Obliques?
I consider that the traction test for oblique muscle examination is not useful in this case since the posterior restrictions generated by the inflammatory and fibrous process do not allow us to adequately evaluate the eyeball rotation manoeuvres to identify the action of the oblique muscles, and which is, on the contrary, very useful in other pathological entities.

7) Would You Weaken the SO if You Are Doing a Bilateral IR Recession to Prevent A Pattern?
I think that weakening of both inferior rectus muscles, especially when they are fibrous or tense, as in CFEOM type I can cause a secondary A pattern, that is why I add the simultaneous transposition. In one case of CFEOM type I, operating under topical anaesthesia, I simultaneously performed the weakening of the both superior obliques demonstrating the little effect on the divergence, that is why I consider that the displacements during the recession of both inferior rectus muscles is sufficient.

8) Do You Take into Account Late Overcorrection After IR Recession, Especially in Adjustable Surgery?
Yes, we should always keep in mind the possibility of late overcorrection after inferior rectus recession, especially in monocular surgery, which is why I always prefer to leave little undercorrection. When we leave the patient with a minimal hypotropia, we can see that in a few months it has been corrected, which is preferable to leaving it in a good orthotropia at the beginning, but then possibly later having an overcorrection.

9) Would You Use Vicryl or Non Absorbable Sutures for the Inferior Rectus?
I always use non-absorbable sutures when I operate a highly tense inferior rectus muscle and try to ensure adequate and secure fixation to the sclera; and generally I also use more tendon for my suture compared when I operate a normal tension muscle.

10) What is Your Response to Per mm of Recession in Tight Thyroid Muscles?
The response for each mm of muscular recession in thyroid strabismus is generally increased, especially when the test shows a tight muscle, so I always prefer to do every time a small amount of recession, especially when operating inferior rectus muscles, so we can correct an important amount of strabismus no related with the minimum of the recession, for example. To know how much recession I should do, I do traction tests with the sutures and check to decrease the tension with the least recession.
But I think that this is not the case anymore when the orbital infiltrative process is more severe on the non-muscular posterior tissues, fat, etc., since this generates a more generalized restriction of the eyeball and the response to muscular surgery is no longer the common one; or as this case, the natural fixation and support of muscles tissues has been lost because of the previous decompression surgery, it is when, despite doing a good recession, the residual strabismus is still important, or even sometimes like we haven’t done anything, and that is when we have to especially consider the need to perform combined techniques, such as adding botulinum toxin injection in the muscle to be recessed at the same time of surgery, or even, as in this case, the need to do the resection of the opposing muscles.