Increased orbital volume after periodic intrabulbar injections of silicone in growing rabbits

The intent of this experiment was to determine whether with an increase in ocular mass there would be an increase in orbital volume. Eighteen, four‐week old, 220 to 420 gm Dutch rabbits were used. In 12 animals silicone was injected into one eye but not the opposite one. No silicone was injected into the eyes of six untreated rabbits. In a ten week period the total amount of ten silicone injections into each treated eye ranged from 1.2 to 1.6 ml. After each rabbit was euthanatized, elastic rubber base imprints were made of both cleaned orbits to determine the volumes. In the untreated animals the differences between the right and left orbital volumes ranged from — 0.1 to 0.2 ml (— 2.4 to 4.7%). The mean of the differences was not statistically significant. When the eyes were injected with silicone, the differences in orbital volumes between the injected and non‐injected sides ranged from 0.6 to 0 ml (14.6 to 0%). The mean of the differences was 0.3 ml which is statistically significant. It was concluded that periodic intrabulbar injections of silicone in the growing rabbit significantly increased orbital volume.