Evaluation of Variables Influencing Orbital Implant Motility

Purpose To evaluate the variables influencing orbital implant motility following enucleation. Methods This was a single-centre observational, non-randomised, non-masked cohort study in 54 enucleated eyes. A standard ruler measured (SRM) vertical and horizontal movements to calculate a total motility score (TMS), comprising adduction, abduction, up-gaze, and infraduction. Variables assessed included implant size and type, presence of post-enucleation socket syndrome (PESS), and reason for enucleation. Student’s T-test was used to analyse differences between variables influencing implant motility. Statistical significance was set at P < 0.05. Results Fifty-four eyes from 54 patients were assessed: 22 (40.7%) with acrylic implants and 32 (59.3%) with hydroxyapatite. Implant sizes were 18mm (3 patients), 20mm (17), and 22mm (28). Mean time since enucleation was 1,367 days, median 282 days. Motility differences between acrylic and hydroxyapatite implants were not statistically significant (P = 0.36), though acrylic showed higher motility (mean TMS = 14.1mm vs 12.8mm). Larger implants showed greater TMS. Patients with PESS had poorer motility (12.8mm vs 13.6mm, P = 0.61). Motility was better without trauma (13.6mm vs 12.5mm, P = 0.38). Conclusions Type and size of implant, PESS, and trauma influenced motility without reaching significance. Surgical technique may play a more prominent role in long-term motility.