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 Table of Contents  
Year : 2020  |  Volume : 32  |  Issue : 1  |  Page : 87-88

Concerns in the surgical treatment of intermittent exotropia

Department of Ophthalmology, Chaithanya Eye Institute, Kochi; Vettam Eye Clinic, Mulanthuruthy, Ernakulam, Kerala, India

Date of Submission06-Mar-2020
Date of Acceptance06-Mar-2020
Date of Web Publication17-Apr-2020

Correspondence Address:
Dr. Sanitha Sathyan
Vettam Eye Clinic, Perumpilly, Mulanthuruthy, Ernakulam - 682 314, Kerala
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Source of Support: None, Conflict of Interest: None

DOI: 10.4103/kjo.kjo_28_20

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Management of intermittent exotropia raises several concerns, regarding the indication for surgery, timing of the surgery, and the type of surgical procedure. This article attempts to highlight the controversial aspects of surgical management of intermittent exotropia and the consensus, in light of current evidence.

Keywords: Controversies, intermittent exotropia, overcorrection, surgery, timing of surgery

How to cite this article:
Sathyan S. Concerns in the surgical treatment of intermittent exotropia. Kerala J Ophthalmol 2020;32:87-8

How to cite this URL:
Sathyan S. Concerns in the surgical treatment of intermittent exotropia. Kerala J Ophthalmol [serial online] 2020 [cited 2020 Aug 4];32:87-8. Available from: http://www.kjophthal.com/text.asp?2020/32/1/87/282668

Exotropia is one of the most common types of strabismus in children,[1],[2] especially in Asian populations. Intermittent exotropia X(T) is the most common subtype of exotropia.[2],[3],[4] Despite being a prevalent form of strabismus, the management of intermittent exotropia remains controversial. The natural history of X(T) remains unclear, and many studies have shown that a considerable percentage of patients who were delayed immediate surgery showed improvement in the ocular alignment in the long term.[5],[6],[7] A recent randomized control study concluded that in intermittent exotropes between 3 and 10 years of age, for whom the surgery was not immediately considered, stereoacuity deterioration or progression to constant exotropia over 3 years was uncommon. The study also showed that exotropia control, stereoacuity, and magnitude of deviation remained stable or improved slightly at 3 years.[8] Results of this longitudinal study favor delaying surgical intervention in many cases with X(T) and call for change in practice patterns in the management of X(T).

The second controversy is regarding the assessment of fusional control in cases with X (T). The measurement of the amount of deviation is more or less standardized using prisms. However, determination of the grade of fusional control remains problematic and often results in suboptimal surgical results. The Newcastle score was designed to provide a better guide to assess the control in cases with intermittent exotropia. However, the home control part in Newcastle score is based upon recall by the parents and may be subjective, inaccurate, or biased.[9] Therefore, another score solely based upon office control has been designed.[10] However, in the practical scenario, the decision to operate remains the choice of a surgeon and is difficult to define objectively, unlike the case of esotropias, where the indications are clearer. The choice of methods to assess the fusional control in X(T) needs to be better defined.

The third controversy is regarding the timing of surgery in X(T). The main goals of surgery in intermittent exotropia are to preserve binocularity[11] and to improve psychosocial quality of life.[12],[13],[14],[15],[16],[17] The decision to operate is mainly based on four aspects: increasing angle of exodeviation, deteriorating control of X(T), decrease in stereopsis for near or distance, and quality of life. This problem also adds to the timing of surgery for intermittent exotropia. Early surgery is recommended by some authors to preserve binocularity and to achieve optimum results.[11],[18],[19],[20] Many other surgeons advocate delayed surgery for fear of overcorrections.[21],[22],[23] A few others have concluded that age at surgery does not affect the surgical outcome.[24],[25],[26],[27],[28] The consensus regarding the appropriate age for surgical intervention still remains unanswered.

Planned initial overcorrection in the surgery for X (T) was supported by some studies. They argued that the long-term alignment was better when slight overcorrection is planned and that the overcorrection would resolve within 6 weeks of surgery.[26],[29],[30],[31] However, a few others did not find that overcorrection beneficial.[18],[32]

These controversies in the management of X (T) remain unsettled and lack consensus at the practice level.

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Conflicts of interest

There are no conflicts of interest.

  References Top

Chia A, Dirani M, Chan YH, Gazzard G, Au Eong KG, Selvaraj P, et al. Prevalence of amblyopia and strabismus in young Singaporean Chinese children. Invest Ophthalmol Vis Sci 2010;51:3411-7.  Back to cited text no. 1
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Mohney BG, Huffaker RK. Common forms of childhood exotropia. Ophthalmology 2003;110:2093-6.  Back to cited text no. 3
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Pediatric Eye Disease Investigator Group, Writing Committee, Mohney BG, Cotter SA, Chandler DL, Holmes JM, et al. Three-year observation of children 3 to 10 years of age with untreated intermittent exotropia. Ophthalmology 2019;126:1249-60.  Back to cited text no. 8
Haggerty H, Richardson S, Hrisos S, Strong NP, Clarke MP. The Newcastle Control Score: A new method of grading the severity of intermittent distance exotropia. Br J Ophthalmol 2004;88:233-5.  Back to cited text no. 9
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Hatt SR, Leske DA, Holmes JM. Comparison of quality-of-life instruments in childhood intermittent exotropia. J AAPOS 2010;14:221-6.  Back to cited text no. 14
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Satterfield D, Keltner JL, Morrison TL. Psychosocial aspects of strabismus study. Arch Ophthalmol 1993;111:1100-5.  Back to cited text no. 17
Pratt-Johnson JA, Barlow JM, Tillson G. Early surgery in intermittent exotropia. Am J Ophthalmol 1977;84:689-94.  Back to cited text no. 18
Abroms AD, Mohney BG, Rush DP, Parks MM, Tong PY. Timely surgery in intermittent and constant exotropia for superior sensory outcome. Am J Ophthalmol 2001;131:111-6.  Back to cited text no. 19
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Edelman PM, Brown MH, Murphree AL, Wright KW. Consecutive esodeviation. Then what? Am Orthopic J 1988;38:111-6.  Back to cited text no. 21
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Beneish R, Flanders M. The role of stereopsis and early postoperative alignment in long-term surgical results of intermittent exotropia. Can J Ophthalmol 1994;29:119-24.  Back to cited text no. 24
Folk ER. Surgical results in intermittent exotropia. AMA Arch Ophthalmol 1956;55:484-7.  Back to cited text no. 25
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