Performance assessment of a pupil tracking system for adaptive optics retinal imaging

Adaptive Optics (AO) is particularly suitable for correction of aberrations that change over time - a necessity for high resolution imaging of the retina. The rapidly changing aberrations originating from eye movements require wavefront sensors (WFS) with high repetition rates. Our approach is enhancing aberration correction by integrating a Pupil Tracking System (PTS) into the AO loop of the retinal imaging system. In this study we assessed the performance of the PTS developed for this purpose. Tests have demonstrated that the device achieves an accuracy of <15 μm in a ±2 mm range of eye movements with a standard deviation <10 μm. PTS can tolerate ±5 mm defocus with an increase of 4 μm in mean standard deviation. In vivo measurements done with temporarily paralyzed pupils have resulted in a precision of approximately 13 μm.