Abstract: Immunocompromised or immunosuppressed non-primate chimeric mammalian hosts comprising a neuronal graft in the eye are provided for studying various events associated with humans. Particularly, the chimeric host may have solely human fetal neuronal xenografts or other fetal xenografts with other tissue, where the various tissues may be studied as to their response to a variety of agents, their response to pathogens or other diseased states, or their response to agents for the treatment of the various indications.

Abstract: An intraretinal delivery and withdrawal instrument which has (a) a curved, distal frame for insertion into an orbit, which insertion is effected (i) inferior to the supraorbital ridge, (ii) superior to the eye, and (iii) in a caudal direction so as to reach the retina; (b) a tip for penetration into the subretinal region of the eye connected to the frame; and (c) an adjustable collar connected to the tip which collar is capable of being positioned so that the collar regulates the depth of tip penetration into the subretinal region including methods for uses thereof.

Abstract: An intraretinal delivery and withdrawal instrument which has (a) a curved, distal frame for insertion into an orbit, which insertion is effected (i) inferior to the supraorbital ridge, (ii) superior to the eye, and (iii) in a caudal direction so as to reach the retina; (b) a tip for penetration into the subretinal region of the eye connected to the frame; and (c) an adjustable collar connected to the tip which collar is capable of being positioned so that the collar regulates the depth of tip penetration into the subretinal region including methods for uses thereof.