Figure 1
Imaging of the temporal, outer retina before and during the light stimulation period with white light in a healthy, young volunteer.”n” denotes the measurement index of one volume and therefore represents a non linear axis of time. Volumes are presented as their A-scan average, which is the average of all their A-scans. The duration of each measurement was about five seconds and a break of one minute was held between all measurements except 15 and 16 where the break was five minutes long, due to the longer initial light exposure. (a) Spectrum of the stimulation light. (b) Comparison of two measurements (number 12 and 19) before and during the light stimulation period. The OCT tomogram represents a section of the outer retina, containing photoreceptor outer segments and RPE, and has been averaged along the fast axis, which can be understood as one row of A-scans averaged into one column. (c) VM-scan: rod outer segment tips (ROST) and RPE are clearly separated before light exposure. After light exposure, a distinct change in optical path length between inner segment/outer segment (IS/OS) junction and RPE leads to the convergence and merging of the reflective bands of the ROST and the RPE. Each column represents the A-scan average of a whole volume at any distinct time point (measurement index). (d) En face map of the region of interest at the photoreceptor level. Scale bar corresponds to 3.5 degrees. Retinal vessels were used as landmarks in the en face maps to assure a constant measurement region. (e) Normalized scattering intensity over depth in two measurements (index 12 and 19). The merging of the reflective bands corresponding to the ROST and the RPE is observable in n = 19.
