Tuesday, January 15, 2013

Strabismus Surgery: The Discussion Continues

A colleague of mine (I believe this to be Dr. EA Pennock, a pediatric ophthalmologist (OMD)) responded to one of my earlier posts and then to the one noted below. Please read his comments and then my response:

Dr. Maino, I enjoyed reading your blog and you bring up many good points. However, this page in particular has many unfounded claims and untruths. In the spirit of congeniality I'd like to make a few comments. First, surgery is often NOT the first option for treatment of strabismus. I am an ophthalmologist who specializes in pediatrics and strabismus. If there is a non-surgical option for my patients I always recommend it first. I've even had some parents of accommodative esotropes question me as to why I prescribe glasses instead of just straightening their child's eyes ("can't you just do surgery and be done with it?"). I won't operate when it's not appropriate. In fact, I can't think of any of my esteemed colleagues across the nation who would jump right into strabismus surgery if there were viable non-surgical options. "Strabismus surgery has well [sic] many well-known risks and complications". ANY surgery has well-known risks and complications. These are spelled out to all on Another risk of strabismus surgery? Increased risk of learning disabilities and attention deficit hyperactivity disorder (ADHD) because of exposure to anesthesia.


Dear Dr. Pennock, I would like to respond to your comments (also in the spirit of congeniality).

Saying something has unfounded claims and untruths does not prove it so. If you have published data to support what you say, I would love to see it (no sarcasm here, I really would love to see it). I should also point out that my Canadian colleague had references for many of her statements about strabismus surgery.

I am thrilled that you try non-surgical approaches before surgical intervention. Those patients with accommodative esotropia must wear an appropriate pair of glasses with an add (and maybe even prism). Then if there is a residual strabismus still present, optometric vision therapy should be instituted to improve accommodative (focus) function, oculomotor abilities and (hopefully) fusion. Only then should surgery be considered. I have looked for the data to ascertain how often non-surgical interventions are used by my OMD colleagues and haven't found the information just yet. Do you have one or more papers I could review?

Although as you note, ANY surgery has well-known risks and complications, unfortunately these are not often known by our patients...and may not even be known by our non-eye colleagues.

Strabismus surgery is an option, but only after all non-strabismic interventions have been tried. This should include optometric vision therapy.

I refer to my ophthalmological colleagues for surgical intervention when appropriate. Dr. Peenock, when was the last time you referred to an optometrists for non-surgical intervention? Click here to find some doctors who might be able to improve your surgical outcomes.

Our professions have a great deal to do to improve the care of our patients with strabismus. We also have numerous research studies to conduct in this area for better evidence based treatment options. The first step is recognizing the benefits and problems associated with our current treatment approaches. The next step is to work together to improve outcomes.

I deeply appreciate your comments and hope to be able to continue this conversation in person some day. It is obvious that you care about what you do. It is obvious you want the very best for all your patients. We have this in common. From this common ground, let us begin building a relationship between our professions to break down barriers.

See reviews and articles below for information on strabismus surgery outcomes.

Cochrane Reviews for strabismus surgery:

No reliable conclusions could be reached regarding which technique (adjustable or non-adjustable sutures) produces a more accurate long-term ocular alignment following strabismus surgery or in which specific situations one technique is of greater benefit than the other. High quality RCTs are needed to obtain clinically valid results and to clarify these issues. ......

See: Haridas A, Sundaram V. Adjustable versus non-adjustable sutures for strabismus. Cochrane Database of Systematic Reviews 2005, Issue 1. Art. No.: CD004240. DOI: 10.1002/14651858.CD004240.pub2
The majority of published literature on the use of botulinum toxin in the treatment of strabismus consists of retrospective studies, cohort studies or case reviews. Although these provide useful descriptive information, clarification is required as to the effective use of botulinum toxin as an independent treatment modality. Four RCTs on the therapeutic use of botulinum toxin in strabismus have shown varying responses ranging from a lack of evidence for prophylactic effect of botulinum toxin in acute sixth nerve palsy, to poor response in patients with horizontal strabismus without binocular vision, to no difference in response in patients that required retreatment for acquired esotropia or infantile esotropia. It was not possible to establish dose effect information. Complication rates for use of Botox™ or Dysport™ ranged from 24% to 55.54%.

See: Rowe FJ, Noonan CP. Botulinum toxin for the treatment of strabismus. Cochrane Database of Systematic Reviews 2012, Issue 2. Art. No.: CD006499. DOI: 10.1002/14651858.CD006499.pub
The main body of literature on interventions for IE are either retrospective studies or prospective cohort studies. It has not been possible through this review to resolve the controversies regarding type of surgery, non-surgical intervention and age of intervention. There is clearly a need for good quality trials to be conducted in these areas to improve the evidence base for the management of IE.
See: Elliott S, Shafiq A. Interventions for infantile esotropia. Cochrane Database of Systematic Reviews 2005, Issue 1. Art. No.: CD004917. DOI: 10.1002/14651858.CD004917.pub2
From PubMed:
Br J Ophthalmol. 2012 Oct;96(10):1291-5. Epub 2012 Aug 11.Surgical intervention in childhood intermittent exotropia: current practice and clinical outcomes from an observational cohort study.
After surgery 65% had fair to poor outcomes and 20% of the subjects remained XT or the XT recurred
BMC Ophthalmol. 2012 Jan 18;12:1. doi: 10.1186/1471-2415-12-1.The improving outcomes in intermittent exotropia study: outcomes at 2 years after diagnosis in an observational cohort.
....8% ...of those treated surgically required second procedures for overcorrection within 6 months of the initial procedure and at 6-month follow-up 21% ... were overcorrected ....
J AAPOS. 2011 Dec;15(6):527-31. doi: 10.1016/j.jaapos.2011.08.007.Postoperative outcomes of patients initially overcorrected for intermittent exotropia.Pineles SL, Deitz LW, Velez FG.
....(49%) were orthotropic to <8 ...="..." 8="8" after="after" b="b" diopters="diopters" exotropia="exotropia" eyes="eyes" means="means" of="of" omment:="omment:" still="still" surgery="surgery" the="the" turned="turned"> (41%)
had recurrence of exotropia >8(Δ), and ... (10%) had monofixational esotropia <10 div="div">
These are only a few examples of why strabismus surgery should not be considered before other forms of intervention are tried. Patients should know surgical outcomes if the data is available. DM


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