Methods: Forty-eight children with cycloplegic refractive error of ≥ 5.00 diopters (spherical equivalent) in each eye. Age < 4 years old at the time of the first visit, and follow-up until the patient was > 8 years old were enrolled. Best-corrected visual acuity (BCVA) and refractive errors were evaluated serially over 8 years old. The presence of strabismus was identified through use of the alternating cover test and examination of duction and version test. The children were divided into 2 groups according to BCVA at 8 years. A BCVA worse than 20/25 in either eye was considered as the presence of amblyopia.

Results: Amblyopia was detected in 20 out of 48 (41.7%) patients. In amblyopia group had a high rate of male children. The refractive error was similar in amblyopic and non-amblyopic children at both 4 and 8 years of age. Strabismus (exotropia and esotropia) was more common in the amblyopia group. A significant correlation was found between refractive errors at 4 years of age and BCVA at 8 years of age (Spearman rho=0.417, p=0.009). BCVA at 4 years of age was also strongly correlated with BCVA at 8 years of age (Spearman rho=0.517, p=0.001).

Conclusions: Early onset myopic children who have strabismus or early onset myopic boys may develop amblyopia.