Purpose:
Adaptive optics scanning laser ophthalmoscope (AOSLO) can be used to diagnose photoreceptor diseases with a 2µm resolution in the horizontal plane. However, the limited field of view prevents a rapid detection of changes and evaluations of the lesion size. The aim of this study was to assess the feasibility and usefulness of our newly developed dioptric AOSLO (d-AOSLO), which is capable of obtaining wide field images of the photoreceptor mosaic.
Methods:
Our d-AOSLO consists of a wavefront sensor, a deformable mirror, a vertical scanner, and a horizontal scanner. The light source for imaging and wavefront sensing is an 840nm super luminescent diode. One healthy volunteer and two patients with occult macular dystrophy were examined through dilated pupils. First, two 10 degree-wide images were obtained at the fovea and at 5 degrees from the fovea. Second, we obtained 2.5 degree-wide images to examine the details of the cone mosaic of the lesion and of the normal retinal area outside the lesion. The lesion size measured by d-AOSLO was compared to that obtained by spectral domain optical coherence tomography (SD-OCT).
Results:
The cone mosaic was resolved in all eyes by 2.5 deg-wide images. In the 10 degree-wide images, the lesion appeared as a low reflecting area. The horizontal and vertical size of the lesion was 2700µm and1400µm in one eye , and 1800µm and 900µm in the other which agreed with that of the photoreceptor layer disruption in the SD-OCT image.
Conclusions:
Wide-view imaging with d-AOSLO is feasible for an overall view of the entire photoreceptor lesion in one image.
Keywords: imaging methods (CT, FA, ICG, MRI, OCT, RTA, SLO, ultrasound) • photoreceptors • macula/fovea