Figure 5.

Coupling efficiency of a light-guiding Müller cell. (a–f) A perfectly straight Müller cell was chosen for the experiment; it was moved in 2-μm steps perpendicular to the divergent light beam to investigate the effects for different coupling conditions into a Müller cell (illustrated in right schemata). (a and f) When the laser light illuminates a region between two Müller cells, no light is guided. The situation corresponds to that in Fig. 2c. (b and e) If the retina was moved to a region close to the center of a Müller cell, only oblique light rays enter the Müller cell. The transmitted spot intensity increased and the spot was displaced (b, below the beam axis; e, above the beam axis). (c and d) For ideal coupling conditions, the laser beam hits the center of a Müller cell. The spot intensity became brightest and no displacement was observed.