Risk Factors Associated with Reoperation for Exposed Hydroxyapatite Orbital Implants

Purpose: We evaluated risk factors associated with reoperation following exposed hydroxyapatite orbital implant placement.Methods: We retrospectively analyzed 34 patients (34 eyes) diagnosed with exposed hydroxyapatite orbital implants at our institution between 2008 and 2022; all patients had a minimum follow-up of 12 months. All patients initially received conservative management. However, if symptoms, such as pain, discharge, or progressive exposure persisted, surgery was undertaken. We analyzed several variables, including age, sex, diabetic status, preoperative diagnosis, surgical approach, implant type and size, and exposed implant surface area. Regression analysis was performed to identify variables associated with reoperation.Results: Of the 34 patients (34 eyes), 17 (50.0%) were managed conservatively, whereas 17 (50.0%) required surgical intervention. Regression analysis revealed a significant association between the size of the exposed area and the need for reoperation (p = 0.018); however, other factors did not significantly impact reoperation rates. Receiver operating characteristic curve analysis identified a threshold of 4.5 mm for exposed area size, with an area under the curve of 0.934, sensitivity of 0.882, and specificity of 0.824. Patients categorized into small and large groups based on the 4.5 mm threshold revealed a statistically significant difference in reoperation rates (<i>p</i> < 0.001).Conclusions: Our study demonstrates that the size of the exposed area is the single most significant predictor of revision surgery in patients with exposed hydroxyapatite orbital implants. Notably, an exposed area > 4.5 mm was associated with a significantly increased risk of reoperation.