Visual and Ocular Characteristics of Anisometropic Children


Purpose: To compare the demographic and ocular characteristics of patients with low and high levels of anisometropia compared with non-anisometropic individuals.

Methods: This cross-sectional study was conducted on 1803 individuals (age range, 1 to 30 years) examined at strabismus clinics between January 2019 and December 2020. Of these, 203 subjects had anisometropia (11.2%); 66 cases were excluded due to the history of prior ocular surgery except from strabismus surgery. Finally, data from 137 subjects were analyzed. Spherical or cylindrical differences of 1.50 or 3.00D between the two eyes were defined as low or high anisometropia, respectively, and isometropic subjects (n = 1600) served as controls.

Results: No significant difference was observed between cases and controls regarding age (10.25 ± 8.41 vs. 9.2 ± 1.7 years; P = 0.133) and sex (P = 0.051). History of ocular surgery was present in 33% of anisometropic patients versus 0.8 % of isometropic cases. The rate of amblyopia was 83% and 2.3% in anisometropic and non-anisometropic groups, respectively. Best corrected visual acuity (BCVA) was comparable in amblyopic eyes in both study groups, while BCVA of nonamblyopic eyes of non-anisometropic subjects was better (non-anisometropic: 0.01 ± 0.01 vs. anisometropic: 0.06 ± 0.17 LogMAR; P = 0.001). Eye deviation was significantly more prevalent among anisometropic patients (36.5% vs. 3.25%, P < 0.001) and exotropia was the common type of deviation. Anisohyperopia and anisomyopia were the most common refractive errors under low and high anisometropia categories, respectively. Simultaneous manifestation of amblyopia and strabismus were observed in 30.6% of anisometropic cases, while only 0.7% of subjects with isometropia had a similar status (P < 0.001).

Conclusion: High rates of amblyopia and strabismus in anisometropic subjects, especially with higher degrees of anomaly, indicate the necessity of early visual acuity and refractive error screening to improve detection and enhance the outcomes of treatment.


Anisometropia, Demographic Factors, Hyperopia, Myopia

1. Rajavi Z, Sabbaghi H, Baghini AS, Yaseri M, Moein H, Akbarian S, et al. Prevalence of amblyopia and refractive errors among primary school children. J Ophthalmic Vis Res 2015;10:408–416.

2. Wang B, Naidu RK, Qu X. The use of rigid gas permeable contact lenses in children with myopic amblyopia: A case series. Cont Lens Anterior Eye 2018;41:224–228.

3. Zhang J, Yu KM. Femtosecond laser corneal refractive surgery for the correction of high myopic anisometropic amblyopia in juveniles. Int J Ophthalmol 2017;10:1678– 1685.

4. Kraus CL, Culican SM. New advances in amblyopia therapy II: Refractive therapies. Br J Ophthalmol 2018;102:1611–1614.

5. Lee CW, Fang SY, Tsai DC, Huang N, Hsu CC, Chen SY, et al. Prevalence and association of refractive anisometropia with near work habits among young schoolchildren: The evidence from a population-based study. PLoS One 2017;12:e0173519.

6. Harrington S, Breslin K, O’Dwyer V, Saunders K. Comparison of amblyopia in school children in Ireland and Northern Ireland: A population-based observational cross-sectional analysis of a treatable childhood visual deficit. BMJ Open 2019;9:e031066.

7. McNeill S, Bobier WR. The correction of static and dynamic aniseikonia with spectacles and contact lenses. Clin Exp Optom 2017;100:732–734.

8. Hepschke JL, Ung L, Cabrera-Aguas M, Ross C, Kumar N, Lahra MM, et al. Pediatric microbial keratitis: Experience from tertiary referral centers in New South Wales, Australia. Pediatr Infect Dis J 2020;39:883–888.

9. Kulikova IL, Pashtaev NP, Batkov YN, Pikusova SM, Terent’eva AE. Femtosecond laser-assisted lasik in children with hyperopia and anisometropic amblyopia: 7 years of follow-up. J Refract Surg 2020;36:366–373.

10. Eissa SA. Management of pseudophakic myopic anisometropic amblyopia with piggyback Visian® implantable collamer lens. Acta Ophthalmol 2017;95:188–193.

11. Vasavada V, Srivastava S, Vasavada SA, Sudhalkar A, Vasavada AR, Vasavada VA. Safety and efficacy of a new phakic posterior chamber IOL for correction of myopia: 3 years of follow-up. J Refract Surg 2018;34:817–823.

12. Yildirim Y, Cakmak S, Sucu ME, Kepez Yildiz B, Kirgiz A, Akbas YB, et al. Comparative study of smallincision lenticule extraction and phakic intraocular lens implantation for the correction of high myopia: 6-year results. J Cataract Refract Surg 2020;47:221–226.

13. Sucu ME, Cakmak S, Yildirim Y, Yildiz BK, Yalçınkaya G, Beşek NK, et al. Explantation of phakic intraocular lenses: causes and outcomes. Int Ophthalmol 2020;41:265–271.

14. Krarup TG, Nisted I, Christensen U, Kiilgaard JF, la Cour M. The tolerance of anisometropia. Acta Ophthalmol 2020;98:418–426.

15. Hashemi H, Pakzad R, Yekta A, Bostamzad P, Aghamirsalim M, Sardari S, et al. Global and regional estimates of prevalence of amblyopia: A systematic review and meta-analysis. Strabismus 2018;26:168–183.

16. Faghihi M, Hashemi H, Nabovati P, Saatchi M, Yekta A, Rafati S, et al. The prevalence of amblyopia and its determinants in a population-based study. Strabismus 2017;25:176–183.

17. Li YP, Zhou MW, Forster SH, Chen SY, Qi X, Zhang HM, et al. Prevalence of amblyopia among preschool children in central south China. Int J Ophthalmol 2019;12:820–825.

18. Dikova SP, Dragoev SA, Chernodrinska VS. Prevalence of amblyopia in Bulgaria. Strabismus 2018;26:163–167.

19. Wang B, Naidu RK, Qu X. The use of rigid gas permeable contact lenses in children with myopic amblyopia: A case series. Cont Lens Anterior Eye. 2018;41:224–228.

20. Tychsen L. Refractive surgery for children: Excimer laser, phakic intraocular lens, and clear lens extraction. Curr Opin Ophthalmol 2008;19:342–348.

21. Dvali ML, Tsintsadze NA, Mirtskhulava SI. Features of hyperopic LASIK in children. J Refract Surg 2005;21:S614–S616.

22. Astle WF, Fawcett SL, Huang PT, Alewenah O, Ingram A. Long-term outcomes of photorefractive keratectomy and laser-assisted subepithelial keratectomy in children. J Cataract Refract Surg 2008;34:411–416.