Imaging of Laser-Photocoagulated Diabetic Microaneurysm With Spectral Domain Optical Coherence Tomography

Abstract

Summary Statement: Microaneurysms were evaluated with SD-OCT before and after photocoagulation. Focal photocoagulation may be a less invasive method for treating microaneurysms and that SD-OCT is useful for evaluating the efficacy of photocoagulation. Methods: In 13 eyes of diabetic patients who underwent focal photocoagulation for clinically significant macular edema, microaneurysms were evaluated before and immediately, 1 month and 2 months after photocoagulation with SD-OCT.The microaneurysms were also evaluated by fluorescein angiography and color fundus photography. The patients underwent focal photocoagulation for microaneurysm.Results: The microaneurysms before photocoagulation in SD-OCT were observed as circular or elliptical structures with hyper-reflective foci within vessel walls. Immediately after photocoagulation, the microaneurysms were changed to indistinct lesions with hyper-reflectivity around the microaneurysms. Acoustic shadows developed on the choroidal side of the microaneurysms. If photocoagulation for microaneurysms was appropriately done, retinal changes were limited to within the inner-retina around the microaneurysms and no changes were observed in retinal pigment epithelium. Within 2 months after 5 photocoagulation, the microaneurysms changed into fine scars, and the retinal structure normalized. Average retinal thickness of the fovea was 432±70 μm before the procedure, but reduced to 373±84 μm at 2 months post-surgery.Conclusions: Focal photocoagulation may be a less invasive method for treating microaneurysms and that SD-OCT is useful for evaluating the efficacy of photocoagulation.

Structural Changes in Individual Retinal Layers in Diabetic Macular Edema

“…Among the capsular structure patterns, the “incomplete” and “absent” types, in contrast to the “complete” type, often were accompanied by fluorescein leakage and cystoid spaces [36, 37]. Recently, using SD-OCT, clinicians have confirmed that the number of microaneurysms decrease after focal photocoagulation, which suggested that in the future FA would be replaced with noninvasive OCT to evaluate treatment efficacy [38, 39]. …”

The Pearl Necklace Sign

“…Scattered hyperreflective foci on OCT have been well described in diabetic patients with DME and were observed throughout all retinal layers and within the walls of intraretinal microaneurysms. [21][22][23] Subfoveal hyperreflective foci have also been noted in patients with diabetic maculopathy with serous macular detachments. 24 The deposits could not be identified by biomicroscopy, fundus photography, or infrared imaging as long as they were not confluent.…”

Theoretical investigation of loading Ni clusters on the α-Ga2O3 surfaces for photocatalytic hydrogen evolution

“…Among developed photocatalytic semiconductors, materials with d 10 configuration exhibit excellent photocatalytic activity [5][6][7][8] , mainly because their conduction bands are composed of the mixture of s and p orbitals with large dispersion, which is favorable to provide photoexcited electrons with large mobility [9] . Gallium oxide (Ga 2 O 3 ) is a typical metal oxides with d 10 metal ions, exhibiting high activity for degradation of organic pollutants and decomposition of water [10][11][12][13][14][15] . It is found that loading proper cocatalysts on Ga 2 O 3 plays an essential role in achieving photocatalytic hydrogen evolution reaction (HER) with high activity [10,11,16,17] .…”

“…Gallium oxide (Ga 2 O 3 ) is a typical metal oxides with d 10 metal ions, exhibiting high activity for degradation of organic pollutants and decomposition of water [10][11][12][13][14][15] . It is found that loading proper cocatalysts on Ga 2 O 3 plays an essential role in achieving photocatalytic hydrogen evolution reaction (HER) with high activity [10,11,16,17] . Experiments show that cocatalysts not only construct active sites but also promote charge separation for redox reactions [18][19][20] .…”

“…Since the nickel oxide cocatalyst is the mixture of Ni and NiO components and often written as NiO x in literatures [32][33][34][35][36][37][38][39] . Yanagida and co-workers showed that when semiconductor Ga 2 O 3 was applied as the photocatalyst without loading NiO x , the activity was quite low and only H 2 production was obtained [10] . Wang et al found that loading NiO x cocatalysts is required to induce the stoichiometric generation of H 2 and O 2 by photocatalytic water splitting on Ga 2 O 3 with tunable α-β phase junctions [11] .…”