Iori Wada

Optical coherence tomography angiography reveals spatial bias of macular capillary dropout in diabetic retinopathy

Purpose Our purpose is to evaluate the spatial bias of macular capillary dropout accompanying diabetic retinopathy (DR) using optical coherence tomography angiography (OCTA). Methods This study included 47 patients with diabetes and 29 healthy individuals who underwent OCTA. Retinal capillary flow density (FD) of 2.6 × 2.6 or 5.2 × 5.2 mm foveal area as well as the four divided areas (superior, inferior, temporal, nasal) without a foveal avascular zone (FAZ) at the superficial capillary plexus and deep capillary plexus (DCP) were measured respectively using ImageJ and NI Vision. Spatial biases of FD (orientation bias ratio and hierarchical bias ratio) and the correlation between FAZ and FD were examined. Results OCTA showed focal capillary dropout in DR patients. The orientation bias of FD was significantly higher in NPDR compared to NDR in the DCP (P = 0.03). The hierarchical bias of FD was significantly shifted to a DCP dominance with progression of DR (P < 0.01). In addition, the FD and FAZ area were significantly inversely correlated in both plexus in DR patients but not in healthy subjects (P < 0.01). Conclusions Area-divided OCTA quantification shows the appearance of spatial biases of macular capillary dropout with the onset of DR, suggesting that DR-related macular capillary dropout occurs locally and randomly. Future studies are necessary to determine the clinical relevance of the spatial pattern of capillary dropout in DR.

Rho-Kinase/ROCK as a Potential Drug Target for Vitreoretinal Diseases

Rho-associated kinase (Rho-kinase/ROCK) was originally identified as an effector protein of the G protein Rho. Its involvement in various diseases, particularly cancer and cardiovascular disease, has been elucidated, and ROCK inhibitors have already been applied clinically for cerebral vasospasm and glaucoma. Vitreoretinal diseases including diabetic retinopathy, age-related macular degeneration, and proliferative vitreoretinoapthy are still a major cause of blindness. While anti-VEGF therapy has recently been widely used for vitreoretinal disorders due to its efficacy, attention has been drawn to new unmet needs. The importance of ROCK in pathological vitreoretinal conditions has also been elucidated and is attracting attention as a potential therapeutic target. ROCK is involved in angiogenesis and hyperpermeability and also in the pathogenesis of various pathologies such as inflammation and fibrosis. It has been expected that ROCK inhibitors will become new molecular target drugs for vitreoretinal diseases. This review summarizes the recent progress on the mechanisms of action of ROCK and their applications in disease treatment.

Imaging of Retinal Vascular Layers: Adaptive Optics Scanning Laser Ophthalmoscopy Versus Optical Coherence Tomography Angiography

Purpose Retinal vascular networks are observed as a layered structure residing in a nerve fiber layer and an inner nuclear layer of the retina. This study aimed to evaluate reflectance confocal adaptive optics scanning laser ophthalmoscopy (AO-SLO) for imaging of the layered retinal vascular networks. Methods This study included 16 eyes of 16 healthy cases. On the fovea, 2.8- and 3.0 mm2-areas were imaged using a prototype AO-SLO and optical coherence tomography angiography (OCTA), respectively. AO-SLO images focused on the nerve fiber and photoreceptor layers were recorded in the area. Two different vessel images (capillary networks in the superficial layer and in all layers) were generated to examine if the deep capillary network could be distinguished. We compared AO-SLO with OCTA in imaging of the layered retinal vascular networks. Results Sufficient images of capillary networks for analysis could be generated when the motion contrast was enhanced with AO-SLO movies in seven cases (43.8%). The deep capillary network could be distinguished in the merged image. Vascular depiction performance in AO-SLO was significantly better than in OCTA at both 0.5- and 1.0-mm areas from the fovea (P < 0.05). Conclusions Retinal vascular imaging using AO-SLO might be a useful adjunct to OCTA as a supportive method to evaluate the retina in healthy patients and patients with disease. Translational Relevance In cases requiring accurate and detailed retinal vasculature observation, AO-SLO might be useful for evaluating retinal vascular lesions as a supportive imaging method of OCTA.

Regorafenib-induced retinal and gastrointestinal hemorrhage in a metastatic colorectal cancer patient with liver dysfunction: A case report

Rationale: Regorafenib is effective for metastatic colorectal cancer but its toxicity such as hemorrhage should be considered. The safety of regorafenib for the patient with the liver disease is not known. Patient concerns: Seventy-one-year old man of colon cancer had myodesopsia and blood stool after 14 days from the initiation of regorafenib administration with 50% dose reduction due to liver dysfunction. Diagnoses: Fundus examination revealed hemorrhage of the retinal vein. Interventions: Regorafenib treatment was discontinued and observational therapy was pursued. Outcomes: Retinal and gastrointestinal hemorrhage resolved in 1 week. Lessons: Retinal hemorrhage should be considered as the differential diagnosis of myodesopsia in the patient treated by regorafenib. Safety and pharmacokinetic of continuous regorafenib administration for patients with liver dysfunction remains to be clarified.

Quantifying metamorphopsia with M-CHARTS in patients with idiopathic macular hole

Purpose The purpose of this study was to determine the degree of metamorphopsia using M-CHARTS™ in patients with idiopathic macular hole before and after pars plana vitrectomy and internal limiting membrane (ILM) peeling. Patients and methods The records of 22 eyes of 22 patients with a full-thickness macular hole who underwent pars plana vitrectomy and ILM peeling were reviewed. All patients underwent a complete ophthalmic examination including spectral-domain optical coherence tomography (OCT). Horizontal metamorphopsia (MH) and vertical metamorphopsia (MV) scores were determined using M-CHARTS at the same time. The time course of changes in metamorphopsia and the relationship between best-corrected visual acuity (BCVA) and OCT parameters were assessed. Results Sealing of the macular hole was noted in all eyes after surgery. BCVA improved significantly from 1 month after surgery (P<0.001). The MV score was significantly higher than the MH score before surgery (P<0.05) and improved significantly from 1 month after surgery (P<0.03). The MH score improved significantly at 6 months after surgery (P<0.001). The postoperative MV and MH scores became closer to one another from 1 month after surgery. Moreover, the MV score was higher than the MH score at all postoperative assessments. There was a significant correlation between the MV and MH scores at all follow-up assessments. There was no significant correlation between BCVA and the MV or MH score at any follow-up assessment. Conclusion The satisfaction of the patients with macular hole after surgery cannot be necessarily measured by BCVA alone, because M-scores were not correlated to BCVA in postoperative evaluation. Therefore, evaluation of the MV and MH scores can be an independent treatment outcome in addition to BCVA.