Vision 1 Year after Gene Therapy for Leber's Congenital Amaurosis

Each video shows fixation epochs of 10-second duration to one of four target luminances from brighter (2.7 log10) to dimmer (1.8 log10). The small circle indicates the location of the continuously illuminated deep-red target (685-nm peak, 80-nm full width at half maximum). The target subtended 1 degree in the visual field. The normal perceptual threshold was close to 0.0 log10 (arbitrary) units. Video imaging of the retina was performed monocularly with near-infrared light (MP1, Nidek Technologies America). Translation of each video frame with respect to a reference image was recorded at 25 Hz. Video representations of the fixation data were generated by applying the horizontal and vertical offset values to a near-infrared image of the fundus; each translated image then contributed a single frame of the video which was played back at the same 25-Hz rate as the original recording. Isosensitivity contours defining the foveal and superotemporal regions of vision derived from microperimetric examinations are shown for reference (white lines). At the 1-month visit, the patient perceived the three highest luminance targets and fixated using the foveal region (videos 1 through 3). The lowest luminance target was not perceived, and the patient attempted to point straight ahead with a resulting fixation overlapping with the fovea as well as a larger extrafoveal region (video 4). At the 12-month visit, the patient perceived all four targets, including the dimmest target that was not perceived at all previous visits (videos 5 through 8). For the highest luminance target, fixation was at the fovea (video 5). At incrementally lower target luminances, fixation dwelled for increasingly longer periods in the superotemporal retina that was treated (videos 6 through 8).

Category:

Science & Technology

Tags:

• gene therapy
• retinal degeneration
• congenital blindness
• Leber's Congenital Amaurosis