Self-inflating hydrogel expanders have been used to treat anophthalmia and blind microphthalmia. This study aimed to investigate the long-term outcomes of treatment with self-inflating hydrogel expanders for congenital anophthalmia and blind microphthalmia.In this retrospective study, the medical records of 161 patients with anophthalmia and blind microphthalmia who underwent hydrogel expansion were reviewed. We measured the palpebral fissure height (PFH), palpebral fissure length (PFL), and distance between the inner canthal and mid-nasal line (ICMN) before and after surgery. Cox regression analysis was conducted to determine which variables were related to the implantation of spherical expanders following hemispherical expander implantation.After treatment, the PFH and PFL increased significantly (p < 0.001). Complications including expander migration and extrusion occurred in 15 cases. Five patients needed enucleation or further dermis fat graft implantation because of insufficient expansion. The necessity for further spherical expansion was substantially related to a relative axial length (rAL) <0.5 (p = 0.007).Self-inflating hydrogel expansion can significantly increase the lid fissure. The occurrence of complications is rare, and surgical intervention can effectively address them. Abnormal eyes with a rAL of less than 0.5 demonstrate a higher possibility of needing additional orbital expansion.Copyright © 2024 British Association of Plastic, Reconstructive and Aesthetic Surgeons. Published by Elsevier Ltd. All rights reserved.