Background: High astigmatism is frequently associated with congenital ptosis. Ptosis surgery itself may also induce astigmatic refractive change that will cause amblyopia in young children. The purpose of this study was to assess postoperative astigmatic change and the effect of different ptosis surgical procedures on astigmatism.
Methods: An analysis of 63 consecutive surgical cases of congenital ptosis was conducted. The preoperative incidences of anisometropia, amblyopia, strabismus and high astigmatism were evaluated. All patients underwent levator resection or received frontalis sling. The postoperative astigmatic change after the follow-up period of 12 months was assessed in 28 patients. It included a total of 40 ptotic eyelids from 12 bilateral and 16 unilateral cases of ptosis. The eyes on the contralateral side in unilateral cases served as the control group.
Results: In 63 cases of congenital ptosis, 30.2% (19/63) were associated with anisometropia and 39.7% (25/63) with amblyopia, and 11.1% (7/63) were combined with strabismus. Most cases of amblyopia were associated with high astigmatism (64%). The incidence of high astigmatism (> 2.5 diopters, D) in congenital ptosis was 25.3%. Of 40 ptotic eyelids included for the study of postoperative astigmatism change, 15% showed an increase of more than 0.5 D, whereas 27.5% showed a decrease of more than 0.5 D, and no significant change was observed in 57.5%. An average decrease of 0.18 D in astigmatism was observed, while no statistical difference was found between the study group and the control group for astigmatic change. Moreover, both the levator resection and frontalis sling groups showed a decrease in average cylinder, and again, demonstrated no statistically significant difference in astigmatic change.
Conclusions: A high incidence of amblyopia was associated with astigmatism in congenital ptosis. Postoperative astigmatic study also revealed some change in astigmatic power, but no new cases of amblyopia developed after ptosis surgery. Patients with congenital ptosis should have cycloplegic refraction as soon as possible, and long-term postoperative refraction check-up is also recommended.