Characterization of In Vivo Retinal Lesions of Diabetic Retinopathy Using Adaptive Optics Scanning Laser Ophthalmoscopy

Figure 2

Multimodal imaging (color fundus photo, OCT, IR image, and AOSLO) of six hallmark lesions: a microaneurysm, MA (A–D), a blot hemorrhage (E–H), a cotton wool spot, CWS (I–K), intraretinal cysts (L–N), hard exudate, HE (O–R), and neovascular proliferation, NV (S–V). (A) Microaneurysm visible as small red dot in 30° color fundus photo (CF) centered on the macula. (B) In the corresponding B-scan the inner plexiform layer, MA is visible primarily by its shadowing effect on the outer retinal layers. (C) In the AOSLO image focused at the vascular level, the MA is visible as a well-defined saccular bulge within the capillary network. Feeding and draining vessels (arrowheads) are discernable. (D) When focused at the photoreceptor plane, shadowing from the MA is present surrounded by a clearly imaged photoreceptor mosaic. (E) Small blot hemorrhage easily visible in 30° color fundus photo and Spectralis IR image (F) but not clearly identifiable in the corresponding cross-sectional SDOCT B-scan. G Outlines of the hemorrhage are blurred even in the AOSLO image focused at the hemorrhage plane. (H) When focused on the photoreceptor plane, there is shadowing of the photoreceptor mosaic by the anteriorly located blot hemorrhage. (I) CWS clearly visible in 30° Optos color fundus image and Spectralis IR image (J). In the corresponding SDOCT B-scan, the CWS appears as a nodular thickening of the retinal nerve fiber layer (RNFL) compressing the inner plexiform and inner nuclear layer. Notice the faint shadowing effect on the outer retinal layers. (K) Montage of 17 AOSLO images focused at the RNFL level to cover an area of 3° × 4.5°. The CWS appears hyperreflective with a less clearly delineated nerve fiber striation pattern compared to adjacent areas. Nerve fiber bundles adjacent to the CWS are pushed aside at the lower right border of the lesion. (L) DME is not evident on the 30° color fundus and Heidelberg Spectralis IR (M) photographs, but is clearly visible on the montaged MSL AOSLO images (N) and corresponding SDOCT B-scan. The white boxes in (L) and (M) correspond to the area imaged on AOSLO (N). An asterisk marks a microaneurysm and [1, 2] indicates corresponding cysts in the AOSLO (N) and SDOCT (M) images. (O) The HE is clearly visible on color fundus photography (O) OCT and IR image (P). In confocal AOSLO images (Q), the HE appears as a hyperreflective granular structure with an internal honeycomb-like pattern. Two months after intravitreal ranibizumab injections for center involved diabetic macular edema, the HE decreased in size to reveal an intact photoreceptor pattern. (S) Fundus photograph of neovascularization elsewhere (NVE) that is clearly visible on OCT and IR image (T). (U) Corresponding NVE imaged with AOSLO before treatment (U) and 3 months after administration of intravitreal ranibizumab (V). AOSLO imaging reveals the persistence of an involuted neovascular formation.