Purchase this article with an account.
M. Pircher, B. Baumann, H. Sattmann, E. Götzinger, C. K. Hitzenberger; Temporal Changes of Single Cone Photoreceptors Observed in vivo With High Speed, High Resolution SLO/OCT. Invest. Ophthalmol. Vis. Sci. 2009;50(13):5171.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
To demonstrate the capability of transversal scanning (TS) optical coherence tomography (OCT) to observe long term changes of single human cone photoreceptors.
A TS OCT system operating at a frame rate of 40 fps (imaging area ~300 x 300µm2) was used to record 3D data sets of the human cone mosaic. To minimize axial eye motion artifacts a high speed depth tracking device was developed and implemented into the TS-OCT instrument. The accuracy of the device and the high loop speed of 1kHz enabled the reduction of the residual tracking error below the axial resolution of the OCT system (<5µm). Simultaneously recorded scanning laser ophthalmoscope (SLO) images were used to correct for transverse eye motion. Because the cone mosaic represents a unique pattern exactly the same location can be found within averaged SLO images and within en-face OCT images. Therefore corrected 3D volumes recorded at different times could be aligned to each other with an accuracy better than the extension of a single cone using software based algorithms.
Practically no changes of cone photoreceptors could be observed within a measurement series recorded in 15 minutes which demonstrates the good reproducibility of the system. However, changes of single cone photoreceptors within the imaging area could be observed from day to day in the majority of the cone photoreceptors. These changes include: Differing backscattered intensities either from the junction between inner outer segments (IS/OS) and/or the posterior tips of outer segments (PTOS), changes in outer segment lengths and changes of the relative position of IS/OS and/or PTOS.
Due to the fast transverse imaging speed of the instrument and the implemented axial eye tracking, the system is capable to image in vivo exactly the same location on the retina from measurement to measurement with cellular resolution. This technology enables for the first time temporal studies of changes of cone photoreceptors that might lead to a better understanding of the underlying physiology.
This PDF is available to Subscribers Only