BACKGROUND: Prior studies comparing ophthalmic outcomes after treating unicoronal synostosis (UCS) by early endoscopic strip craniectomy (ESC) versus later fronto-orbital advancement (FOA) are modest in sample size, or lack consistent age adjustment. We report long-term, age-adjusted ophthalmic outcomes for a large cohort after nonrandomized treatment by one of these two options. METHODS: The following data was retrieved from a retrospective review of the medical records of patients with treated UCS born since 2000: cycloplegic refractions, sensorimotor examinations, and strabismus procedures before craniofacial repair and postoperatively at approximately 18 and 60 months of age. V-pattern strabismus was graded as mild (absent or + 1/-1 oblique dysfunction) versus moderate-to-severe (≥+2/-2 oblique dysfunction or left to right vertical alignment change of ≥20Δ or ocular torticollis >15°). RESULTS: A total of 120 infants were included: 60 treated by FOA and 60 by ESC. By the late examination, aniso-astigmatism was present in 71.8% of FOA-treated patients and 46% of ESC-treated patients (P < 0.0001). By late examination, the age-adjusted odds ratio of moderate-to-severe V-pattern strabismus after treatment by FOA versus ESC was 2.65 (95% CI, 1.37-6.28; P = 0.02); strabismus surgery was performed in 26 infants treated by FOA compared with 13 treated by ESC (OR = 2.8; P = 0.02). Amblyopia developed in 60% of FOA-treated patients compared with 35% of those treated by ESC (OR 3.0; 95% CI, 1.3-6.7; P = 0.02). CONCLUSIONS: Our age-adjusted ophthalmic results confirm better long-term outcomes after treatment of USC by endoscopic strip craniectomy. Recognition and referral of affected infants by the earliest months of life facilitates the opportunity for endoscopic repair.