[Passive mechanical characteristics of the eyeball joint system during rabbit ontogenesis]

The postnatal development of vestibulo-ocular reactions is among other factor probably caused by changes of the passivee mechanical properties of the bulb joint system. Therefore, curarized rabbits from the newborn up to the adult age were studied in respect of the passiv deviation of the ocular bulb. The required force of stepwise traction (5 degrees each) of the bulb between the primary position and a 20 degrees deviation was measured. A linear enhancement of the force with increasing deviation angles was found in all age groups. Force relief resulted in a hysteresis in each case, the bulb did not reach the primary position. There were no differences of the force between newborns and adult animals, but 16 to 20 d old rabbits exhibited a statistical significant decrease of the required force in all deviation steps, except in 5 degrees.