**6. Considerations in children**

The anophthalmic or microphthalmic socket in children has special features that we will discuss. One of the most important issues is that the orbit of the child should continue growing after the eye is removed. The surgeon must have that in mind in order to achieve good cosmetic and anatomical results. This will condition the implant selection.

The most frequent cause of enucleation in pediatric age is retinoblastoma. There has been a special concern whether to place an implant in these orbits due to the difficulties in the followup and the detection of tumor recurrence with an orbital implant in place. However, once it was observed that orbits in children with no orbital implants did not develop appropriately, the decision to implant was taken. Normal face and bony orbit growth depends on the orbital soft tissue contents. When the child is five and a half years old, his face is about 90% of the size of an adult's face [45]. Generally talking, the management of an anophthalmic socket in a child younger than 5 years old requires an implant that can increase in size, such as a dermis-fat graft or orbital tissue expander. A large fixed-sized orbital implant can be placed in children older than 5 years [46]. Orbital growth is completed by the time the child is 12-14 years old [47]. Dermis-fat grafts harvested from the thigh have shown to stimulate orbital growth in children [48], but their motility is poor. Thus, this is an ideal implant for children younger than 5 years old. The dermis-fat graft is also used to cover hydroxyapatite exposures and to reconstruct sockets. A low incidence of complications has been reported with hydroxyapatite implants in a large series of pediatric patients who had undergone enucleation surgery for different reasons after 60 months of follow-up and excellent cosmetic results. We should not forget that when treating an anophthalmic cavity in a child, we need to increase the conjunctival fornices, increase the width of the palpebral fissure promoting at the same time the eyelid growth, and expand the orbital bones. These goals can be achieved with a good surgical implant and the use of progressively larger conformers.

Jordan and Klapper recommend choosing the implant depending on several factors. If a child younger than 5 years undergoes enucleation, they choose a 16-18 mm of diameter wrapped nonporous implant (e.g., silicone). They stress that you should introduce the biggest implant that does not create tension when closing the Tenon's and conjunctival layers. Another option may be dermis-fat grafts, knowing that they can reabsorb and loose some of its volume and taking into account that the artificial eye movements will be very limited. In children aged 5-15 years, they recommend hydroxyapatite or aluminum oxide [16]. On the other hand, Shah et al. used hydroxyapatite implants with low complication rates and good motility and high patient/family cosmetic satisfaction on long-term follow-up in 531 orbits of children with an average age of 3 years.
