To evaluate the clinical characteristics of amblyopia between amblyopic siblings.

Siblings diagnosed with monocular amblyopia were included in the present study and were classified into older and younger groups according to age. All siblings were treated for amblyopia for at least three months. The age at diagnosis, type of amblyopia, and visual acuities of the amblyopic eye and sound eye were compared between the two groups. The therapeutic results were analyzed.

The age at diagnosis of 13 sibling pairs was 4.7 ± 1.6 and 3.8 ± 1.6 years, a difference that was not statistically different ( p = 0.169). Nine of 13 sibling pairs had the same type of amblyopia; anisometropic amblyopia in 7 pairs and strabismic amblyopia in 2 sibling pairs. There were no significant differences in the visual acuities of the amblyopic eye and sound eye at diagnosis. There were no differences in visual acuity or lines of improvement from baseline visual acuity in the amblyopic eye at the final follow-up.

Age at diagnosis, cause of amblyopia, and visual acuities of the amblyopic and sound eyes were similar in siblings with monocular amblyopia. There was no difference in treatment results for amblyopia between siblings.