The invention provides peptide derivatives designed to deliver peptides having growth factor inhibitory activity, especially somatostatin analogs, to the retina by sequential metabolism. A pair of casting pool confinement plates are thrust against the ends of rolls by thrusters mounted with the side plastes on carriages forming part of moveable structures which are connected to the outer rends of nozzle pieces by pins and which can be moved by operation of screw jacks. When the master ECU detects a given ECU that is in an abnormal state, it restarts, through the communications network, the given ECU to return to an initial state. Still further, the bit comprises a plurality of primary cutter elements mounted to the second primary blade in different radial positions. The outer dimension of the lens barrel is kept from increasing.