An apparatus includes an optics tube extending from a proximal end to a distal end and a distal tip member positioned proximate the distal end of the optics tube. The optics tube includes a cladding material, a core material encased by the cladding material and configured to transmit light from the proximal end of optics tube to the distal end, and a lumen defined by the core material. A core wire is disposed in the lumen. The core wire is configured to prevent longitudinal stretching of the optics tube.
