An apparatus to exchange a fluid of a container implantable in an eye , the apparatus comprising: a needle defining an injection lumen configured for injecting a therapeutic agent into the container implanted in the eye through a distal opening; a sheath structure providing one or more channels extending along the needle ; an elongate structure collectively formed by the needle and the sheath , the elongate structure comprising a proximal portion , an intermediate portion , and a distal portion extending along an axis, the intermediate portion extending along the axis between the proximal portion and the distal portion , the sheath structure extending over the needle along the proximal portion and the intermediate portion , and the proximal portion of the sheath structure comprising one or more openings into an outflow path (140P1) from the container; wherein the distal portion of the elongate structure comprises a tip shaped to penetrate tissue and a barrier of the container when the container is implanted in the eye ; a first receiver container coupled to the elongate structure and configured to receive fluid via the outflow path (140P1); characterized in that : a second receiver container coupled to the elongate structure and configured to receive fluid via the outflow path (140P1); a valve positioned in fluid communication with the outflow path (140P1), wherein injection of a fluid through the injection lumen displaces fluid from the container through the one or more openings into the outflow path (140P1), and wherein the valve directs flow of the fluid displaced from the container into at least one of the first receiver container and the second receiver container . a needle defining an injection lumen configured for injecting a therapeutic agent into the container implanted in the eye through a distal opening; a sheath structure providing one or more channels extending along the needle ; an elongate structure collectively formed by the needle and the sheath , the elongate structure comprising a proximal portion , an intermediate portion , and a distal portion extending along an axis, the intermediate portion extending along the axis between the proximal portion and the distal portion , the sheath structure extending over the needle along the proximal portion and the intermediate portion , and the proximal portion of the sheath structure comprising one or more openings into an outflow path (140P1) from the container; wherein the distal portion of the elongate structure comprises a tip shaped to penetrate tissue and a barrier of the container when the container is implanted in the eye ; a first receiver container coupled to the elongate structure and configured to receive fluid via the outflow path (140P1); characterized in that : a second receiver container coupled to the elongate structure and configured to receive fluid via the outflow path (140P1); a valve positioned in fluid communication with the outflow path (140P1), wherein injection of a fluid through the injection lumen displaces fluid from the container through the one or more openings into the outflow path (140P1), and wherein the valve directs flow of the fluid displaced from the container into at least one of the first receiver container and the second receiver container . a second receiver container coupled to the elongate structure and configured to receive fluid via the outflow path (140P1); a valve positioned in fluid communication with the outflow path (140P1), wherein injection of a fluid through the injection lumen displaces fluid from the container through the one or more openings into the outflow path (140P1), and wherein the valve directs flow of the fluid displaced from the container into at least one of the first receiver container and the second receiver container . <EOS>