Effects of congenital ptosis on the refractive development of eye and vision in children.

Aim: To investigate the influence of unilateral congenital ptosis on the development of the eye and vision in children.

Methods: In this prospective observational study, 41 patients with unilateral congenital ptosis were enrolled (age range 3-15y). The blepharoptosis was divided into 3 subgroups according to the margin reflex distance-1 (MRD-1), including mild group (MRD-1≥2 mm), moderate group (0≤MRD-1<2 mm), and severe group (MRD-1<0 mm). The fellow eyes served as controls. All subjects underwent ocular examinations, including axial length, keratometry, and refractive error.

Results: The incidence of astigmatism (ptotic eyes: 58.5% fellow eyes: 24.4%, =0.002) and magnitude of cylindrical power (ptotic eyes: -0.86±0.79 D fellow eyes: -0.43±0.63 D, =0.003) differed significantly between the ptotic eyes and the fellow eyes. The spherical equivalent refraction (=0.006), spherical power (=0.01), cylindrical power (=0.011), axial length-corneal radius (AL/CR) ratio (=0.009), frequency of hyperopia (=0.002) and astigmatism (=0.004) were significantly different among the ptotic eye subgroups and the fellow eye group. In addition, in patients with congenital ptosis, the incidence of amblyopia is 43.9% and the incidence of anisometropia is 24.4%. More importantly, the ratio of AL/CR showed significantly positive correlation with the severity of ptosis (=0.002).

Conclusion: Congenital ptosis may lead to a delayed eyeball development in the aspect of AL/CR. The risk of amblyopia is also increased due to visual deprivation and aggravated anisometropia, particularly in severe ptosis case.