APPARATUS FOR MAINTAINING FLUID PRESSURE IN AN OCULAR GLOBE AT A PREDETERMINED LEVEL

An ophthalmic device and system for measuring and controlling relative pressure of fluid inside an ocular globe includes a surgical instrument which is adapted to penetrate the ocular globe. A fluid pressure transducer is mounted on the instrument so that, when the instrument penetrates the ocular globe, the transducer is located adjacent to an opening that communicates with the interior of the globe so that it can react to pressure changes in the fluid therein and generate signals in response to pressure changes in the fluid. The signal is transmitted external of the instrument to a pump or other fluid transfer device which is operatively connected to the transducer for first receiving signals and then supplying or removing fluid from the ocular globe in response to the signals according to a predetermined set of instructions. The pump is connected to a closed loop in which fluid is continuously circulated. Fluctuations in intraocular pressure cause the pump to speed up or slow down and then supply fluid to or remove fluid from the ocular globe through a conduit connected to the closed loop.