Unilateral Congenital Ptosis Is Associated With Impaired Binocular Vision and Reduced Contrast Sensitivity in Children

Purpose: To evaluate binocular visual function and quantitative contrast sensitivity function (qCSF) in children with unilateral congenital ptosis and determine whether abnormalities varied with ptosis severity. Methods: Forty-five children with unilateral congenital ptosis and 26 healthy controls were enrolled. Worth 4-dot responses, synoptophore fusion, near and distance stereoacuity, and qCSF testing were assessed. Outcomes were compared between groups and analyzed according to margin reflex distance 1–based severity. Regression analyses were adjusted for age and absolute cylindrical refractive error. Eye-related functional vision and quality of life were additionally assessed using the Pediatric Eye Questionnaire. Results: Compared with controls, children with ptosis had a reduced divergence amplitude, a smaller fusion range, poorer near stereoacuity, and poorer distance stereoacuity (2.60 [interquartile range (IQR), 2.00–4.00] vs. 2.00 [IQR, 2.00–2.53] log arcsec; P = 0.001). Absent distance stereopsis was more frequent in the ptosis group (40.0% vs. 0.0%; P < 0.001). Children with ptosis also had a lower area under the log CSF (1.27 [IQR, 1.19–1.41] vs. 1.39 [IQR, 1.28–1.47]; P = 0.009) and a lower spatial frequency cutoff (1.19 [IQR, 1.09–1.26] vs. 1.27 [IQR, 1.22–1.30]; P < 0.001). These abnormalities were most evident in severe ptosis. After adjustment, severe ptosis remained associated with a poorer distance stereoacuity, lower area under the log CSF, and lower spatial frequency cutoff. Children with ptosis also had lower Pediatric Eye Questionnaire scores across child-, proxy-, and parent-reported domains. Conclusions: Children with unilateral congenital ptosis showed binocular dysfunction and reduced contrast sensitivity despite preserved visual acuity, especially in severe ptosis. Binocular visual function and qCSF assessment may provide additional information in evaluating congenital ptosis.