Normally, from birth to adulthood, the orbits develop in proportion to the bones of the skull, while accommodating and meeting the exponential growth of the eyeball during development. Fetal and infant eyelid, fossa, orbit, and maxillofacial development are dependent on the presence and development of the normal eye, especially the development of the orbital bones. Although different researchers have come to different conclusions regarding the orbital growth curve, they all agree that the orbital growth period is the fastest before 1 year of age and is the critical period for the entire developmental period of the orbit. Bentley’s MRI measurements of orbital volume in children aged 8 months to 15 years with non-ophthalmic diseases showed that orbital volume at 5 years of age is a cutoff for orbital development, with a linear increase in orbital volume until 5 years of age and a significant decrease in growth rate thereafter. The main influences on delayed orbital development include congenital microphthalmos and anophthalmos, acquired anophthalmos, ocular atrophy, and ocular radiation therapy. Acquired anophthalmos is defined as those who have undergone ocular extraction or removal of eye contents after birth and is commonly associated with various reasons such as trauma, intractable intraocular malignancies, refractory inflammatory conditions inside and outside the eye, painful, lightless eyes, and to improve appearance. The most common diseases requiring ocular removal in young children are ocular tumors, among which retinoblastoma (RB) is the most common intraocular tumor in children. 80% of children are diagnosed before the age of 3 years, and the average age of diagnosis is 2 years, which is an important period of rapid orbital growth. 2001 Peylan-Ramu and 2012 Lin et al. found that orbital growth was delayed after orbital removal for retinoblastoma, despite intraorbital implantation of a hydroxyapatite prosthesis. Furthermore, orbital development is more severely affected in children who have had their eyes removed when they are younger than 1 year old. With the improvement of diagnosis and treatment, the cure rate of RB patients is now higher than 90% and more and more children with RB are surviving for a long time. Thus, it is increasingly important to evaluate and correct post-treatment developmental appearance and long-term complications that affect their quality of life.