The optics best suited for floater treatment with a YAG laser is: all six beams of the laser and the slit lamp must be made nearly coaxial. The six beams consist of the two aiming beams, the treatment beam, the illuminating beam from the slit lamp, and the two viewing beams. With all beams nearly coaxial the floater can be seen, aimed upon, and treated regardless of how deep the floater is located in the vitreous. If the laser does not have this optical set up, one can treat floaters in the anterior vitreous, but visualization will not be adequate in the mid and posterior vitreous.

Laser Set Up Diagram

In other words, your YAG laser needs ideally about the same beam arrangement as the typical argon laser with which you can see burns you make on the retina. Unfortunately, several YAG lasers do not have the optical set up needed. Their usual deficiency is the illuminating beam originates from an angle far below the treatment beam to reduce reflexes during posterior capsulotomies. With such an arrangement the illumination may be blocked by the iris when working in the mid and posterior vitreous. The ideal placement of the illumination beam is just inferior to the bottom of the treatment beam.