Clinical Characteristics of Intermittent Exotropia in Children with Myopia and Myopic Anisometropia

Abstract

Objective

Previous studies have yielded contradictory conclusions on the relationship between intermittent exotropia (IXT) and the magnitude of myopia, especially in children. The aim of this study was to determine the clinical characteristics of IXT in children with myopia and myopic anisometropia.

Methods

We retrospectively evaluated the clinical data of patients (4–15 years of age) with convergence insufficiency (CI)-IXT and basic IXT who underwent surgery between 2022 and 2023. All patients underwent cycloplegia before the examinations and surgery. The degree of strabismus was measured when the patient viewed from the center of the glasses. Ocular dominance was routinely tested in children with IXT via the “hole-in-card test” after best-corrected visual acuity was obtained. Children were subsequently grouped into 2 groups (anisometropia and nonanisometropia) according to the difference in binocular spherical equivalent (SE) values (≥ 1.0 diopters [D]).

Results

A total of 197 patients were included in the study. The preoperative deviation at near was significantly lower in the basic IXT group than in the CI-IXT group, whereas the distance exodeviation was significantly greater in the basic IXT group than in the CI-IXT group (P < 0.05). Patients with anisometropia were older than those without anisometropia (P < 0.001). The dominant eyes had significantly less myopia than the nondominant eyes did in the CI-IXT and anisometropia groups (P = 0.049 and P = 0.003, respectively). High myopia was more prevalent in middle school students with IXT (16.67%) than in preschool students (4.55%) and primary schoolchildren (3.18%). The percentage of individuals with anisometropia (≥ 3.0 D) varied in the low (1.68%), moderate (8.7%), and high myopia groups (22.22%). Binomial logistic regression analysis revealed that age and SE of the dominant eye were independent factors related to anisometropia in children with IXT (P < 0.001 and P < 0.001, respectively).

Conclusion

Patients with IXT, especially those with anisometropia and CI-IXT, were shown to have less myopia in the dominant eye. Age and SE of the dominant eye were found to be independent factors related to anisometropia in children with IXT.

Keywords

Intermittent exotropia / Myopia / Anisometropia / Children

References

[1] Ma MM, Scheiman M. Divergence excess and basic exotropia types of intermittent exotropia: a major review. Part 1: prevalence, classification, risk factors, natural history and clinical characteristics. Strabismus. 2023;31(2):97–128.

[2] Kim S, Babiuch A, Xiao H, et al.. Comparison of Myopia Progression among Myopic Children with Intermittent Exotropia and No Strabismus. Optom Vis Sci., 2023, 100(8): 508-514

[3] Ekdawi NS, Nusz KJ, Diehl NN, et al.. The development of myopia among children with intermittent exotropia. Am J Ophthalmol., 2010, 149(3): 503-507

[4] Meng Q, Wang L, Zhao M, et al.. Comparing myopic error in patients with basic and convergence insufficiency intermittent exotropia in China. BMC Ophthalmol., 2023, 23(1): 290

[5] Oruz O, Pelit A, Akar S, et al.. Refractive change in pediatric patients with intermittent exotropia. J AAPOS., 2023, 27(5284.e1-284.e4

[6] Shen T, Liang M, Chen L. Myopic progression in school-aged children with moderate intermittent exotropia. Front Pediatr., 2023, 11: 1192387

[7] Cheng CY, Yen MY, Lin HY, et al.. Association of ocular dominance and anisometropic myopia. Invest Ophthalmol Vis Sci., 2004, 45(8): 2856-2860

[8] Chia A, Jaurigue A, Gazzard G, et al.. Ocular dominance, laterality, and refraction in Singaporean children. Invest Ophthalmol Vis Sci., 2007, 48(83533-3536

[9] Cao Y, Gu X, Zhang Y, et al.. Assessment of the effects of myopic and hyperopic anisometropia on choroidal vascular structure in children using SS-OCTA. Ophthalmic Physiol Opt., 2024, 44(3): 525-536

[10] Gong W, Chen H, Yang F, et al.. Intereye Differences in Ocular Biometric Parameters of Concomitant Exotropia. Front Med., 2021, 8 724122

[11] Burian HM. Exodeviations: their classification, diagnosis and treatment. Am J Ophthalmol., 1966, 62(6): 1161-1166

[12] Deng L, Gwiazda JE. Anisometropia in children from infancy to 15 years. Invest Ophthalmol Vis Sci., 2012, 53(7): 3782-3787

[13] Qiao S, Chen J, Zhang J, et al.. Study on the impact of refractive anisometropia on strabismus, stereopsis, and amblyopia in children. Medicine., 2024, 103(44 e40205

[14] Kim YJ, Kim TG. Analysis of 2-year spherical equivalent progression in emmetropic children with noncycloplegic refraction: a retrospective chart review. BMC Ophthalmol., 2023, 23(1): 131

[15] Wang Z, Li T, Zuo X, et al. 0.01% Atropine Eye Drops in Children With Myopia and Intermittent Exotropia: The AMIXT Randomized Clinical Trial. JAMA Ophthalmol. 2024;142(8):722–730.

[16] Kim DH, Jung JH, Choi MY, et al.. A cross-sectional study of ophthalmologic examination findings in 5385 Koreans presenting with intermittent exotropia. Sci Rep., 2023, 13(11329

[17] Moon Y, Kim JH, Lim HT. Difference in myopia progression between dominant and nondominant eye in patients with intermittent exotropia. Graefes Arch Clin Exp Ophthalmol., 2020, 258(61327-1333

[18] Yang HK, Hwang JM. Decreased accommodative response in the nondominant eye of patients with intermittent exotropia. Am J Ophthalmol., 2011, 151(1): 71-76.e1

[19] Somer D, Demirci S, Cinar FG, et al.. Accommodative ability in exotropia: predictive value of surgical success. J AAPOS., 2007, 11(5): 460-464

[20] Morgan IG, French AN, Ashby RS, et al.. The epidemics of myopia: Etiology and prevention. Prog Retin Eye Res., 2018, 62: 134-149

[21] Singh NK, Mani R, Hussaindeen JR. Changes in stimulus and response AC/A ratio with vision therapy in Convergence Insufficiency. J Optom., 2017, 10(3): 169-175

[22] Wen Y, Shen T, Yam JCS, et al.. Refractive Profile of Surgical Patients with Intermittent Exotropia: A Large-Sample Cross-Sectional Study in Southern China. Curr Eye Res., 2023, 48(12): 1133-1143

[23] Horwood AM, Riddell PM. Evidence that convergence rather than accommodation controls intermittent distance exotropia. Acta Ophthalmol., 2012, 90(2): e109-e117

[24] Du YQ, Zhou YH, Ding MW, et al.. Observation of peripheral refraction in myopic anisometropia in young adults. Int J Ophthalmol., 2023, 16(12): 2082-2088

[25] Hashemi H, Khabazkhoob M, Emamian MH, et al.. All biometric components are important in anisometropia, not just axial length. Br J Ophthalmol., 2013, 97(12): 1586-1591

[26] Hu YY, Wu JF, Lu TL, et al.. Prevalence and Associations of Anisometropia in Children. Invest Ophthalmol Vis Sci., 2016, 57(3): 979-988

[27] Hashemi H, Khabazkhoob M, Lança C, et al.. Prevalence of anisometropia and its associated factors in school-age children. Strabismus., 2024, 32(1): 1-10

[28] Zhou Y, Zhang XF, Chen XJ, et al.. Prevalence of anisometropia and influencing factors among school-age children in Nantong, China: a cross-sectional study. Front Public Health., 2023, 11: 1190285

[29] Kekunnaya R, Chandrasekharan A, Sachdeva V. Management of Strabismus in Myopes. Middle East Afr J Ophthalmol., 2015, 22(3): 298-306

[30] Kinori M, Nitzan I, Szyper NS, et al.. Correlation of Refractive Error with Anisometropia Development in Early Childhood. Am J Ophthalmol., 2024, 264: 145-153

[31] Lin HW, Young ML, Pu C, et al.. Changes in anisometropia by age in children with hyperopia, myopia, and antimetropia. Sci Rep., 2023, 13(113643

[32] Linke SJ, Baviera J, Munzer G, et al.. Association between ocular dominance and spherical/astigmatic anisometropia, age, and sex: analysis of 10,264 myopic individuals. Invest Ophthalmol Vis Sci., 2011, 52(129166-9173

[33] Jiang S, Chen Z, Bi H, et al.. Elucidation of the more myopic eye in anisometropia: the interplay of laterality, ocular dominance, and anisometropic magnitude. Sci Rep., 2019, 9(1): 9598

[34] Hashemi H, Khabazkhoob M, Yekta A, et al.. Prevalence and risk factors for anisometropia in the Tehran eye study. Iran. Ophthalmic Epidemiol., 2011, 18(3122-128

[35] Quek TP, Chua CG, Chong CS, et al.. Prevalence of refractive errors in teenage high school students in Singapore. Ophthalmic Physiol Opt., 2004, 24(1): 47-55

[36] Zhang XB, Jiang HH, Zhang LL, et al.. Potential causal associations between leisure sedentary behaviors, physical activity, sleep traits, and myopia: a Mendelian randomization study. BMC Ophthalmol., 2024, 24(1): 104

[37] Yam JC, Zhang XJ, Kam KW, et al. Myopia control and prevention: From lifestyle to low-concentration atropine. The 2022 Josh Wallman Memorial Lecture. Ophthalmic Physiol Opt. 2023;43(3):299–310.

[38] Jones LA, Sinnott LT, Mutti DO, et al.. Parental history of myopia, sports and outdoor activities, and future myopia. Invest Ophthalmol Vis Sci., 2007, 48(83524-3532

[39] Hsu CC, Lee LC, Chang HC, et al.. Comparative Outcomes of Amblyopia Treatment in High Astigmatism: Stability and Sustained Improvements. J Clin Med., 2025, 14(10): 3577

[40] Flitcroft DI, Adams GG, Robson AG, et al.. Retinal dysfunction and refractive errors: an electrophysiological study of children. Br J Ophthalmol., 2005, 89(4484-488

[41] Harvey EM, Twelker JD, Miller JM, et al.. Visual Motor and Perceptual Task Performance in Astigmatic Students. J Ophthalmol., 2017, 2017: 6460281

Funding

the National Natural Science Foundation of China ((82371093)

National Natural Science Foundation of China(81970844)

RIGHTS & PERMISSIONS

The Author(s), under exclusive licence to the Huazhong University of Science and Technology