Background: To report refractive outcomes, describe types of strabismus and evaluate the outcomes of surgical intervention for unilateral coronal synostosis (UCS) in paediatric patients.
Methods: This study retrospectively included 30 UCS cases. Patients aged from 3 months to 6 years (median: 1.8 years) were enrolled from January 2018 to December 2019 at Shanghai Children's Hospital. Sixteen patients had all types of strabismus; 15 of these patients underwent surgery.
Results: Refractive errors of 30 cases were included. In 60% of patients, astigmatism of 1.00D or more existed in not less than one eye at last record. Twenty (66.7%) patients had the larger amount of astigmatism in the contralateral eye. Fifteen patients received strabismus surgery, of whom 6 patients with monocular elevation deficiency (MED) underwent the standard Knapp procedure, with or without a horizontal deviation procedure. Fifteen cases were horizontally aligned within 5 prism dioptres (Δ). Six patients with MED (100%) had attained ≥25% elevation improvement after surgery, and the vertical deviation decreased from 25.83 Δ ± 4.92 Δ (range, 20 Δ-30 Δ) to 0.83 Δ ± 4.92 Δ after surgery (range, 0 Δ-10 Δ), for an improvement of 26.67 Δ ± 4.08 Δ (t = 16 P < 0.05). In 1 patient with esotropia, the horizontal deviation decreased from + 80 Δ to + 5 Δ after surgery. One patient was diagnosed with trichiasis and one with contralateral lacrimal duct obstruction.
Conclusions: Contralateral MED was also the main type of strabismus in UCS. Superior oblique muscle palsy was still the most common, as previously reported. There is a risk of developing a higher astigmatism and anisometropia in the contralateral eye to synostosis. Other ophthalmic disorders should be treated in a timely manner.
Trial registration: The study was approved by the Institutional Review Board of Shanghai Children's Hospital (approval No. 2020R023-E01) and adhered to the tenets of the Declaration of Helsinki. Ethics approval was procured on March 30, 2020. This was a retrospective study. Written informed consent was sought from the patients' parents or legal guardians. Clinical Trials Registry number: ChiCTR2000034910 . Registration URL: http://www.chictr.org.cn/showproj.aspx?proj=56726 .
Keywords: Forced duction test; Monocular elevator deficiency; Standard Knapp procedure; Superior oblique muscle palsy; Unilateral coronal synostosis.