Predicting the ideal implant size before enucleation

Purpose: This study of volume replacement in anophthalmic sockets compares the volume replaced by the implant and prosthesis with the volume removed from the socket and evaluates A-scan ultrasonography as a tool to predict an ideal implant size before enucleation. Methods: In this retrospective study of 59 anophthalmic patients, the volume replaced by the implant and the prosthesis was compared with the volume of the enucleated eye. The volume removed was estimated by calculating the volume of the fellow eye using A-scan ultrasonography. Enophthalmos and superior sulcus deformity were measured and correlated with the percent volume replacement in the anophthalmic sockets. Results: Greater enophthalmos and superior sulcus deformity were found in patients with less than 100% volume replacement compared with those with 100% or more volume replacement. The axial length determined by A-scan ultrasonography of the fellow eye suggested that a larger implant size should have been placed in 76.3% of those patients with less than 100% volume replacement. Sixty-three percent of adult patients could have received an implant more than 22 mm in diameter to fill 80% of the volume removed at enucleation. Conclusions: A-scan ultrasonography of the fellow eye provides a useful tool for predicting the implant size before surgery for optimal volume replacement.