ABSTRACT
OBJECTIVE: To investigate the feasibility of small incision evisceration with an injectable ocular implant that is biocompatible and preserves globe size. DESIGN: Experimental animal study. METHODS: The axial length of the eyes of 12 rabbits was determined by ultrasound before surgery. Subsequently, 12 eyes of 12 separate rabbits were eviscerated and injected with hydroxyapatite (HA) paste (BoneSource; Stryker Leibinger, Kalamazoo, MI). Three rabbits each were killed at 2 weeks, 6 weeks, 3 months, and 6 months after evisceration, and measurements of globe size were compared with measurements of the fellow eye. Histologic examination of the eviscerated eyes was performed. MAIN OUTCOME MEASURES: The axial length and lateral globe measurements of the eviscerated eye were compared with the fellow eye. The eviscerated eye was examined histologically and the degree of inflammation, vascularization, and ossification was noted for each period of observation. RESULTS: The mean preoperative difference in axial length between the control (fellow eyes) and the subsequently eviscerated eyes was 0.15 +/- 0.04 mm (mean +/- standard error of mean). The average axial and lateral globe measurements of the operated eye were 0.8 +/- 0.4 mm less than the fellow eye 2 weeks after surgery, and this difference increased to 3.1 +/- 0.7 mm 6 months after surgery. Histologic examination showed a decrease in granulomatous inflammation and an increase in vascularization of the implanted HA over the time of observation with early osseous metaplasia. CONCLUSIONS: Small incision evisceration is possible with ocular volume replacement with an injectable orbital implant. Injectable HA paste shows promise as an option for implantation after eye evisceration; however, further studies are required to establish the stability of this material for this application.
