Symmetric Versus Asymmetric Bilateral Lateral Rectus Recession in Management of Basic Intermittent Exotropia With Ocular Dominance
Phase: NA
Conditions: Intermittent Exotropia
Sponsor: Benha University

NCT05234957
[
] December 15, 2021 
 
1 
 
 
 
 
 
 
 
 
 
 
 
Symmetric versus Asymmetric Bilateral Lateral Rectus 
Recession in Management of Basic Intermittent Exotropia 
with Ocular Dominance 
 
December 2021 
 
 
 
 
 
 
 
 
 

NCT05234957
[
] December 15, 2021 
 
2 
 
 
 
 
INTRODUCTION 
  Intermittent exotropia (XT), is the commonest type of exodeviation, and represents about 
44.7% of all childhood exotropia[1]. Intermittent XT is classified into basic, true divergence 
excess, pseudo-divergence excess, and convergence insufficiency (CI) type [2, 3] The basic 
type where the deviation is similar at distance and near, is  the most common subtype [4] 
     For basic XT, the choice of surgical procedure is still controversial. Many strabismologists 
prefer bilateral recession surgery (BLR) while others prefer unilateral recess-resect (RR) 
surgery [5-9]. The choice between either strategy depends on many factors including ocular 
dominance and surgical experience. Surgeons weight advantages of each procedure including 
easier surgical manipulations for BLR and higher success rates of the R-R procedure against 
drawback of each procedure including higher rate of recurrence in BLR versus higher rate of 
consecutive esotropia and lateral incomitance for R-R procedure [4, 10-13].  
    Despite ocular dominance is an important factor affecting long term results of surgery, no 
standard surgical procedure has been suggested for exotropic patients with a dominant eye. 
Some studies suggested the R-R procedure on the non-dominant eye for basic XT [2, 7, 10], 
while others suggested BLR, asymmetrical with more recession in the deviating non-
dominant eye [14, 15] or symmetrical without considering effect of ocular dominance on 
surgical decision [16, 17].  
    In our study, we will compare long term motor and sensory effects of symmetric and 
asymmetric BLR recession in treatment of basic XT with a dominant eye.  
 

NCT05234957
[
] December 15, 2021 
 
3 
 
 
 
AIM OF THE WORK 
To study the clinical safety and efficacy of Symmetric versus asymmetric bilateral lateral 
rectus recession in management of basic intermittent exotropia with ocular dominance.  
 
PATIENTS AND METHODS 
  This is a prospective study including patients diagnosed as basic intermittent exotropia with 
a dominant eye in the strabismus unit, ophthalmology department, Benha University 
Hospital. Written informed consent will be provided by legal guardian of each patient before 
inclusion in the study. 
  These patients will undergo complete ophthalmologic and orthoptic examinations before 
surgery including BCVA, cycloplegic refraction, state of ocular dominance and ocular 
motility assessment. The angle of deviation at far and near is measured with the prisms and 
alternating cover test. Eye dominance was determined with the alternative cover test. Sensory 
testing was performed using the Titmus stereo test and the Worth 4-Dot test at distance and 
near.  
  Patients with a history of orbital or scleral buckle surgery, and those with incomitant 
strabismus including thyroid eye disease, myasthenia gravis, Duane syndrome, cranial nerve 
palsies and patient with any degree of preoperative limitation of ductions were excluded. 
Besides, patients with a preoperative A or V-pattern, dissociated vertical deviation, or oblique 
muscle overactions were also excluded. 

NCT05234957
[
] December 15, 2021 
 
4 
 
 Patients will be randomized into two groups. The first group, referred to as the symmetric 
bilateral rectus recession group (S-BLR group). The other group, referred to as the 
asymmetric bilateral rectus recession group (A-BLR group).  
   In the S-BLR group, the amount of recession, based on the largest angle of exodeviation 
measured before surgery, was symmetrically divided between two eyes guided by standard 
strabismus surgical tables. In A-BLR group, the amount of recession in the non-dominant eye 
will be 2 mm more than in the dominant eye.  
  Postoperative measurements will be performed in the same way as the preoperative ones, at 
one week, one month, three months, six months, one year, and later at six months intervals 
after surgery. Outcome parameters at one year after surgery will be used for comparisons and 
analysis. Satisfactory outcome is defined as between 10 PD of exophoria/tropia and 10 PD of 
esophoria/tropia at one year after surgery. Recurrence is considered if alignment is more than 
10 PD of exophoria/tropia, while overcorrection is considered if alignment is more than 10 
PD of esophoria/tropia.  
 
STATISTICAL ANALYSIS  
Statistical analyses were performed using SPSS software version 17.0 (SPSS Inc, Chicago, 
IL). The pre- and postoperative values are described as means plus or minus standard 
deviations. The data were compared using the t test with a P value of < .05 was considered 
statistically significant.  
 
REFERENCES 

NCT05234957
[
] December 15, 2021 
 
5 
 
1. 
Mohney, B.G. and R.K. Huffaker, Common forms of childhood exotropia. 
Ophthalmology, 2003. 110(11): p. 2093-6. 
2. 
Burian, H.M., Exodeviations: their classification, diagnosis and treatment. Am J 
Ophthalmol, 1966. 62(6): p. 1161-6. 
3. 
Audren, F., [Intermittent exotropia]. J Fr Ophtalmol, 2019. 42(9): p. 1007-1019. 
4. 
Kushner, B.J., Selective surgery for intermittent exotropia based on distance/near 
differences. Arch Ophthalmol, 1998. 116(3): p. 324-8. 
5. 
Pratt-Johnson, J.A., J.M. Barlow, and G. Tillson, Early surgery in intermittent 
exotropia. Am J Ophthalmol, 1977. 84(5): p. 689-94. 
6. 
Richard, J.M. and M.M. Parks, Intermittent exotropia. Surgical results in different age 
groups. Ophthalmology, 1983. 90(10): p. 1172-7. 
7. 
Burian, 
H.M. 
and 
B.E. 
Spivey, 
THE 
SURGICAL 
MANAGEMENT 
OF 
EXODEVIATIONS. Am J Ophthalmol, 1965. 59: p. 603-20. 
8. 
Oliva, O. and Á. Morgado, Bilateral lateral rectus recession versus unilateral 
recession/resection for basic intermittent exotropia. Medwave, 2018. 18(6): p. e7319. 
9. 
Mohan, K. and S.K. Sharma, Long-term Motor and Sensory Outcomes After 
Unilateral Lateral Rectus Recession-Medial Rectus Resection for Basic Intermittent 
Exotropia. J Pediatr Ophthalmol Strabismus, 2020. 57(5): p. 326-332. 
10. 
Jeoung, J.W., M.J. Lee, and J.M. Hwang, Bilateral lateral rectus recession versus 
unilateral recess-resect procedure for exotropia with a dominant eye. Am J 
Ophthalmol, 2006. 141(4): p. 683-8. 
11. 
Kim, D.H., H.K. Yang, and J.M. Hwang, Long term surgical outcomes of unilateral 
recession-resection versus bilateral lateral rectus recession in basic-type intermittent 
exotropia in children. Sci Rep, 2021. 11(1): p. 19383. 

NCT05234957
[
] December 15, 2021 
 
6 
 
12. 
Choi, J., et al., The long-term survival analysis of bilateral lateral rectus recession 
versus unilateral recession-resection for intermittent exotropia. Am J Ophthalmol, 
2012. 153(2): p. 343-351.e1. 
13. 
Yuksel, D., M. Spiritus, and S. Vandelannoitte, [Symmetric or asymmetric surgery for 
basic intermittent exotropia]. Bulletin de la Societe belge d'ophtalmologie, 1998. 268: 
p. 195-9. 
14. 
Song, H.J. and H.J. Paik, Augmented Asymmetric Lateral Rectus Recession in 
Intermittent Exotropia With Fixing Eye. jkos, 2010. 51(7): p. 992-997. 
15. 
Cho, Y.A., S.M. Kang, and G.H. Roh, Asymmetric bilateral lateral recti recession in 
intermittent exotropia. Journal of the Korean Ophthalmological Society, 1999. 40(2): 
p. 544-549. 
16. 
Ing, M.R., J. Nishimura, and L. Okino, Outcome study of bilateral lateral rectus 
recession for intermittent exotropia in children. Trans Am Ophthalmol Soc, 1997. 95: 
p. 433-43; discussion 443-52. 
17. 
Lee, H.-J., S.-J. Kim, and Y.S. Yu, Long-term outcomes of bilateral lateral rectus 
recession versus unilateral lateral rectus recession-medial rectus plication in children 
with basic type intermittent exotropia. Eye, 2019. 33(9): p. 1402-1410.