Infantile esotropia

Infantile esotropia is an ocular condition of early onset in which one or either eye turns inward. It is a specific sub-type of esotropia and has been a subject of much debate amongst ophthalmologists with regard to its naming, diagnostic features, and treatment.

Infantile esotropia
Specialty	Ophthalmology

Presentation

Historically the term 'congenital strabismus' was used to describe constant esotropias with onset between birth and six months of age. However, this term was felt to be an inadequate classification as it covered a variety of esotropias with different causes, features and prognoses.

In 1988, American ophthalmologist Gunter K. Von Noorden discussed what he described as 'Essential Infantile Esotropia'.[1] He described the condition as:

"early acquired, not... congenital ..., although congenital factors may favor its development between the ages of 3 and 6 months"

and identified this squint sub-type as having the following features:

1. Onset between birth and six months of age.
2. Large size (greater than 30 dioptres)
3. Stable size
4. Not associated with abnormalities of the central nervous system.
5. Often associated with defective abduction (outward movement) and excessive adduction (inward movement) of the eyes.
6. Also associated with oblique muscle dysfunction and Dissociated Vertical Deviation.
7. Initial alternation of the squint present with crossed fixation, i.e. the affected individual uses the left eye to look right and the right eye to look left.
8. Limited potential for binocular vision.

The same condition had also previously been described by other ophthalmologists, notably Cianca (1962) who named it Cianca's Syndrome and noted the presence of manifest latent nystagmus, and Lang (1968) who called it Congenital Esotropia Syndrome and noted the presence of abnormal head postures. In both cases, however, the essential characteristics were the same, but with emphasis placed on different elements of the condition.

Helveston [2] (1993) further clarified and expanded upon von Noorden's work, and incorporated the work of both Lang and Cianca into his summary of the characteristics of the condition:

1. Esotropia between 10 and 90 dioptres in size
2. Either alternation or fixation preference may be present (if the latter then amblyopia may result).
3. Neurologically normal.
4. Hyperopic correction does not eliminate or significantly reduce the squint size.
5. Frequent nystagmus (latent or manifest latent).
6. The patient may or may not have any or all of the following associated conditions: Oblique muscle dysfunction, vertical incomitance, dissociated vertical deviation, asymmetric optokinetic nystagmus, torticollis.
7. Presence will be 'confirmed' by six months.
8. Best treatment results in subnormal binocular vision.

The expressions congenital esotropia, infantile esoptropia, idiopathic infantile esotropia and essential infantile esotropia are often used interchangeably.

Cross-fixation

Cross-fixation congenital esotropia, also called Cianci's syndrome is a particular type of large-angle infantile esotropia associated with tight medius rectus muscles. With the tight muscles, which hinder adduction, there is a constant inward eye turn. The patient cross-fixates, that is, to fixate objects on the left, the patient looks across the nose with the right eye, and vice versa. The patient tends to adopt a head turn, turning the head to the right to better see objects in the left visual field and turning the head to the left to see those in the right visual field. Binasal occlusion can be used to discourage cross-fixation.[3] However, the management of cross-fixation congenital esotropia usually involves surgery.[4]

Cause

This remains undetermined at the present time. A recent study by Major et al.[5] reports that:

Prematurity, family history or secondary ocular history, perinatal or gestational complications, systemic disorders, use of supplemental oxygen as a neonate, use of systemic medications, and male sex were found to be significant risk factors for infantile esotropia.

Further recent evidence indicates that a cause for infantile strabismus may lie with the input that is provided to the visual cortex.[6] In particular, neonates who suffer injuries that, directly or indirectly, perturb binocular inputs into the primary visual cortex (V1) have a far higher risk of developing strabismus than other infants.[7]

Diagnosis

Differential Diagnosis

Clinically Infantile esotropia must be distinguished from:

1. VIth Cranial nerve or abducens palsy
2. Nystagmus Blockage Syndrome
3. Esotropia arising secondary to central nervous system abnormalities (in cerebral palsy for example)
4. Primary Constant esotropia
5. Duane's Syndrome

Treatment

According to a Cochrane review of 2012, controversies remain regarding type of surgery, non-surgical intervention and age of intervention.[8]

The aims of treatment are as follows:

• The elimination of any amblyopia
• A cosmetically acceptable ocular alignment
• Long-term stability of eye position
• Binocular cooperation

Initially

It is essential that a child with strabismus is presented to the ophthalmologist as early as possible for diagnosis and treatment in order to allow best possible monocular and binocular vision to develop. Initially, the patient will have a full eye examination to identify any associated pathology, and any glasses required to optimise acuity will be prescribed – although infantile esotropia is not typically associated with refractive error. Studies have found that approximately 15% of infantile esotropia patients have accommodative esotropia. For these patients, antiaccommodative therapy (with spectacles) is indicated before any surgery as antiaccommodative therapy fully corrects their esotropia in many cases and significantly decreases their deviation angle in others.[9][10]

Amblyopia will be treated via occlusion treatment (using patching or atropine drops) of the non-squinting eye with the aim of achieving full alternation of fixation. Management thereafter will be surgical. As alternative to surgery, also botulinum toxin therapy has been used in children with infantile esotropia.[11][12][13] Furthermore, as accompaniment to ophthalmologic treatment, craniosacral therapy may be performed in order to relieve tension[14][15] (see also: Management of strabismus).

Surgery

Controversy has arisen regarding the selection and planning of surgical procedures, the timing of surgery and about what constitutes a favourable outcome.

1. Selection and planning

Some ophthalmologists, notably Ing [16] and Helveston,[17] favour a prescribed approach often involving multiple surgical episodes whereas others prefer to aim for full alignment of the eyes in one procedure and let the number of muscles operated upon during this procedure be determined by the size of the squint.

2. Timing and outcome

This debate relates to the technical anatomical difficulties of operating on the very young versus the possibility of an increased potential for binocularity associated with early surgery. Infants are often operated upon at the age of six to nine months of age[18] and in some cases even earlier at three or four months of age.[19] Some emphasize the importance of intervening early such as to keep the duration of the patient's abnormal visual experience to a minimum.[20] Advocates of early surgery believe that those who have their surgery before the age of one are more likely to be able to use both eyes together post-operatively.

A Dutch study (ELISSS)[21] compared early with late surgery in a prospective, controlled, non-randomized, multicenter trial and reported that:

Children operated early had better gross stereopsis at age six as compared to children operated late. They had been operated more frequently, however, and a substantial number of children in both [originally-recruited] groups had not been operated at all.

Other studies also report better results with early surgery, notably Birch and Stager[22] and Murray et al.[23] but do not comment on the number of operations undertaken. A recent study on 38 children concluded that surgery for infantile esotropia is most likely to result in measureable stereopsis if patient age at alignment is not more than 16 months.[24] Another study found that for children with infantile esotropia early surgery decreases the risk of dissociated vertical deviation developing after surgery.[25]

Aside the strabismus itself, there are other aspects or conditions that appear to improve after surgery or botulinum toxin eye alignment. Study outcomes have indicated that after surgery the child catches up in development of fine-motor skills (such as grasping a toy and handling a bottle) and of large-muscle skills (such as sitting, standing, and walking) in case a developmental delay was present before.[26] Evidence also indicates that as of the age of six, strabismic children become less accepted by their peers, leaving them potentially exposed to social exclusion starting at this age unless their eye positioning is corrected by this time[27] (see also: Psychosocial effects of strabismus).

References

1. von Noorden G.k.; A Reassessment of Infantile esotropia. XLIV Edward jackson Memorial lecture; American Journal of Ophthalmology, 1988; 105:1-10
2. Helveston EM (1993). "19th annual Frank Costenbader Lecture--the origins of congenital esotropia". Journal of Pediatric Ophthalmology and Strabismus. 30 (4): 215–32. PMID 8410573.
3. Marc B. Taub; Mary Bartuccio; Dominick Maino (26 September 2012). Visual Diagnosis and Care of the Patient with Special Needs. Lippincott Williams & Wilkins. p. 303. ISBN 978-1-4511-7834-0.
4. Kenneth W. Wright; Yi Ning J. Strube (19 November 2014). Color Atlas Of Strabismus Surgery: Strategies and Techniques. Springer. pp. 16–17. ISBN 978-1-4939-1480-7.
5. Major, Archima; Maples, W.C.; Toomey, Shannon; DeRosier, Wesley; Gahn, David (2007). "Variables associated with the incidence of infantile esotropia". Optometry - Journal of the American Optometric Association. 78 (10): 534–541. doi:10.1016/j.optm.2006.11.017. ISSN 1529-1839. PMID 17904494.
6. Lawrence Tychsen (2012). "The Cause of Infantile Strabismus Lies Upstairs in the Cerebral Cortex, Not Downstairs in the Brainstem". Archives of Ophthalmology. 130 (8). pp. 1060–1061. doi:10.1001/archophthalmol.2012.1481.
7. Tychsen L (2007). "Causing and curing infantile esotropia in primates: the role of decorrelated binocular input (an American Ophthalmological Society thesis)". Transactions of the American Ophthalmological Society. 105: 564–93. PMC 2258131. PMID 18427630.
8. Elliott, S; Shafiq, A (29 July 2013). "Interventions for infantile esotropia". The Cochrane Database of Systematic Reviews. 7 (7): CD004917. doi:10.1002/14651858.CD004917.pub3. PMID 23897277.
9. S.A. Havertape; C.R. Whitfill; O.A. Cruz (1999). "Early-onset accommodative esotropia". Journal of Pediatric Ophthalmology and Strabismus. 36 (2): 69–73. PMID 10204132.
10. F. Koç; H. Ozal; E. Firat (August 2003). "Is it possible to differentiate early-onset accommodative esotropia from early-onset essential esotropia?". Eye (Lond). 17 (6): 707–710. doi:10.1038/sj.eye.6700483. PMID 12928681.
11. Thouvenin D, Lesage-Beaudon C, Arné JL (January 2008). "(translated from French) Botulinum injection in infantile strabismus. Results and incidence on secondary surgery in a long-term survey of 74 cases treated before 36 months of age". J Fr Ophtalmol. 31 (1): 42–50. doi:10.1016/S0181-5512(08)70329-2. PMID 18401298. Retrieved January 3, 2019.
12. de Alba Campomanes AG, Binenbaum G, Campomanes Eguiarte G (April 2010). "Comparison of botulinum toxin with surgery as primary treatment for infantile esotropia". J Aapos. 14 (2): 111–116. doi:10.1016/j.jaapos.2009.12.162. PMID 20451851.
13. Gursoy, Huseyin; Basmak, Hikmet; Sahin, Afsun; Yildirim, Nilgun; Aydin, Yasemin; Colak, Ertugrul (2012). "Long-term follow-up of bilateral botulinum toxin injections versus bilateral recessions of the medial rectus muscles for treatment of infantile esotropia". Journal of American Association for Pediatric Ophthalmology and Strabismus. 16 (3): 269–273. doi:10.1016/j.jaapos.2012.01.010. ISSN 1091-8531. PMID 22681945.
14. Clinical Application of Neuromuscular Techniques: Practical Case Study Exercises. Elsevier Health Sciences. 2005. p. 48. ISBN 978-0-443-10000-0.
15. Leon Chaitow (2005). Cranial Manipulation: Theory and Practice : Osseous and Soft Tissue Approaches. Elsevier Health Sciences. p. 9. ISBN 978-0-443-07449-3.
16. Ing, M.R. (February 1983). "Early Surgical Alignment for Congenital Esotropia". Ophthalmology. 90 (2): 132–135. doi:10.1016/s0161-6420(83)34586-3. PMC 1312199. PMID 6856250.
17. Helveston, E.M.; Ellis, F.D.; Patterson, J.H.; Weber, J. (May 1978). "Augmented Recession of the Medial Recti". Ophthalmology. 85 (5): 507–511. doi:10.1016/s0161-6420(78)35647-5. PMID 673330.
18. Esotropia (Crossed Eyes), Pediatric Ophthalmic Consultants
19. Experts discuss infantile esotropia, airbag injuries and timing of surgery, Ocular Surgery News U.S. Edition, June 1, 2002 (downloaded 3 October 2013)
20. Birch EE, Wang J (2009). "Stereoacuity outcomes after treatment of infantile and accommodative esotropia". Optometry and Vision Science (Review). 86 (6): 647–52. doi:10.1097/OPX.0b013e3181a6168d. PMC 2769257. PMID 19390468.
21. Simonsz HJ; Kolling GH; Unnebrink K. (December 2005). "Final report of the early vs. late infantile strabismus surgery study (ELISSS), a controlled, prospective, multicenter study". Strabismus. 4 (13). pp. 169–199. PMID 16361188.
22. Birch EE, Stager DR Sr.Long-term motor and sensory outcomes after early surgery for infantile esotropia. J AAPOS. 2006 Oct;10(5):409-13
23. Murray AD, Orpen J, Calcutt C. Changes in the functional binocular status of older children and adults with previously untreated infantile esotropia following late surgical realignment. J AAPOS. 2007 Apr;11(2):125-30. Epub 2007 Feb 15
24. Eren Çerman; Muhsin Eraslan; Mehdi S. Öğüt (2014). "The relationship of age when motor alignment is achieved and the subsequent development of stereopsis in infantile esotropia". Journal of American Association for Pediatric Ophthalmology and Strabismus. 18 (3). pp. 222–225. doi:10.1016/j.jaapos.2013.12.017.
25. Arslan U, Atilla H, Erkam N (June 2010). "Dissociated vertical deviation and its relationship with time and type of surgery in infantile esotropia". The British Journal of Ophthalmology. 94 (6): 740–2. doi:10.1136/bjo.2008.157016. PMID 20508049.
26. Babies' Development 'Catches Up' After Surgery To Fix Crossed Eyes, sciencedaily.com, 21 April 2008 (downloaded 4 October 2013)
27. Six-Year-Olds With Squint Less Likely to Be Invited to Birthday Parties, Study Suggests, sciencedaily.com, 19 August 2010 (downloaded 4 October 2013)

External links

Classification	D
External resources	eMedicine: article/1198876

• Infantile esotropia, Medscape, updated 30 May 2012