Exposure Rate Of Unwrapped Orbital Implants In Enucleation Surgery

ObjectiveThe aim of the study was to analyze the long-term exposure rate and to explore the possible risk factors of unwrapped coralline hydroxyapatite(HA)orbital implants.MethodThis was a retrospective case series study of 234 patients(from May 2008 to April 2013)with anophthalmia who underwent insertion of unwrapped HA orbital implants by two different surgical closing techniques.ResultsIn 234 cases,151 underwent the rectus end-to-end suturing closure technique,and 83 underwent the rectus orthotopic suturing closure technique.The time of follow-up mean 41.9 months(ranged from 25 months to 69 months).Implants exposure developed in 11 cases,three in the rectus end-to-end suturing closure group(2.0%),and eight in the rectus orthotopic suturing closure group(9.6%).In the rectus end-to-end suturing technique,a crosswise fixation of vascularised rectus muscle tissue was formed across the front of the implant;In this group the incidence of implant exposure was reduced(OR=8.11,p=0.013).Prior ocular surgery was found to be a factor increasing the incidence of HA exposure(OR=2.73,p=0.032).ConclusionsThe placement of unwrapped HA orbital implants with rectus end-to-end suturing in enucleation surgery was associated with a low rate of exposure in most cases.The end-to-end suturing creates a joint-like structure over the HA sphere,protecting the Tenon’s capsule and conjunctiva from its rough surface and reducing the risk of implant exposure.Prior ocular surgery may be another risk factor for HA exposure.